“Motherhood”: Sculpture at the Catacumba Park, Rio de Janeiro, Brazil
Motherhood. It can mean many things, and our own definition of it is largely defined by our individual experiences. To one person, motherhood might simply mean the act of raising children; to another, motherhood might be what defines them.
It is not uncommon to generalize the concept of “motherhood” and lump everyone who upholds a single criterion – being a mom – into one group. But, really, motherhood affects us all in one way or another, and that way is as unique as the pattern of curves and ridges on a fingertip.
Despite the recent outbreak of (heated) discussion surrounding the Time cover story depicting a beautiful and young woman nursing a toddler, and the questioning if following a certain philosophy makes one more or less of a mother, humans, as a whole, are truly bound by a common goal: to raise the next generation to the best of our abilities under the circumstances at hand. But, there is no one answer.
Every mom will have her own definition of motherhood. But, being a mom is by no means a prerequisite for understanding motherhood as it relates to an individual. For this special Mother’s Day post, we would like to pay homage to motherhood in its many forms. Here you will not find a singular description of motherhood. What you will find, however, is what it means on a more personal level, which is to say that the definition can only come from the heart.
Thank you to all of the wonderful people who participated in this project (and with short notice!) – we have answers in paragraph, tweet, and prose forms.
Motherhood means feeling a kaleidoscope of emotions simultaneously – fear, glee, worry, angst, pride. And it means being an advocate and a revolutionary who empowers her children to engage in society in a meaningful, fun, vibrant way. And lastly, motherhood means always giving up the biggest piece of cake and the last popsicle and being okay with that.
Motherhood means accepting responsibility. If you read the news or listen to the hype, you know what I mean. Every choice you make, from before a child is conceived, until long after you’re dead, there is someone out there that will tell you how it impacted your kid. As my nana always said, “It’s always the mother’s fault.” I just hope that as the time passes I get more credit than blame for how my kids turn out.
Motherhood is how you stretch your heart in ways you never thought possible. It’s how you love through the ups & down, the challenges that life brings. And, it lasts a lifetime from that first tiny cry.
I’m a human geneticist by training, so I’ve been told having a child is the ultimate version of participating in my research. But the science analogy that best summarizes it for me is maternal-fetal microchimerism. Data demonstrating that my son and I each likely have some of each other’s intact cells inside us forever — as I have with my mother, and she with hers, and so on — beautifully represent to me the meaning of motherhood. As the quote from Elizabeth Stone goes, having a child “is to decide forever to have yourheart go walking around outside your body.” To me, that includes half my DNA, some of my cells, and so many of my hopes and dreams, all in one sweet, kissable package.
Motherhood: As a mom of triplets, some would say I have triple the work but I like to think of it as triple the hugs, triple the joy, triple the fun! And when people ask me what it’s like to become a mom I tell them “it’s the toughest job you’ll ever love.” Happy Mother’s Day to all of you amazing, do-it-all moms out there!
I’m a man, so I obviously have no first-hand experience as a mother. That said, I was raised by a (wonderful) single mother, and have had the pleasure of watching my wife be an awesome mom to our three daughters. Those experiences have shaped my impressions of motherhood. To me, motherhood means being kind, but honest. Being gentle, but strong. Being nurturing, but encouraging independence. Motherhood is letting your kids think you are ten feet tall and bulletproof, so they feel you can keep them safe — even though there’s stuff out there that scares the hell out of you. It’s encouraging your kids to learn new things and to work their butts off in school, without making them feel stupid. Motherhood is leading by example when it comes to telling right from wrong, and showing your kids which battles are worth fighting. And, when the time comes, motherhood is letting go of the reins to see where the kids go on their own. Motherhood is not for wimps.
The greatest realization of motherhood for me was that the children we have are people of their own, not “our” children or some kind of nutty, messy, screaming, demanding “other” invading our space, disrupting our lives, and taking our precious time. They are people I love to have around me because they make me laugh, they bring out the teacher in me (not hard to do), they are cool and interesting and imaginative and fun, and each of them (I have three) is a complete individual with a unique personality, outlook, potential, talent, and beautiful, beautiful face that I love to see every day. Just as I choose to spend time with others whom I love, respect, admire, and laugh with, I choose to do the same with my children. That said, I also still have what I had before my children arrived–a happy, full busy life with a partner to whom I seem to grow closer every day, and work that I love. Thanks to my children, I’ve got something even more–three more wonderful people added to my life whom I am deeply delighted and, frankly, honored to know. As Bill Murray’s character in Lost in Translation observes, “They learn how to walk and they learn how to talk… and you want to be with them. And they turn out to be the most delightful people you will ever meet in your life.”
Motherhood is humbling. Of all the endeavors I have tackled in my life, never have I wanted so badly to get everything right and yet known that I would not. Never have I been so emotionally invested in the results, so exhausted by the labor of it, and also, so strangely confident that it will turn out OK. It is the most human thing I have ever done.
For men whose ideas of fatherhood were shaped in large part by its absence in our own lives, motherhood may mean something a bit different. I’m by no means a scholar, but I’ve had the opportunity to speak often and at length with women across the globe on this topic, and to curate their thoughts a bit. These women talk about the feeling of connection to their children they know no one else has. They describe the magic of watching their little ones narrate the moments of discovery in their lives. They talk about how their children “complete the circle” and teach them the other side of unconditional love. They help you understand why people invoke the lioness or the grizzly when describing the protective instinct.
My perspective of motherhood is a lot like that last sentiment – it’s the unyielding power that rises up in you when you realize a little person depends on you for everything. I know that many men step up when left in that situation – I’ve seen it first-hand – but I suspect the feeling is different for women because this little person actually came from you, is an extension of you, is connected to you in ways no man will ever fully understand.
When I think of motherhood, I think of unconditional love. It’s what my mother gave to me, and it’s what I expect I would feel for the children I don’t intend to have. My mother made countless sacrifices for me, but she was independent and did not allow motherhood to define her. She has always encouraged me to be my own person and chase my own dreams. She didn’t want me to feel constrained by gender roles. I feel fortunate to live in a time when motherhood is a choice, not an obligation. I admire my peers who have chosen to have kids, but I’m content to enjoy the rich mother-daughter relationship I have with my mom without feeling obliged to replicate it.
Carin Bondar, Blogger and Filmmaker for Scientific American, the David Suzuki Foundation and Huffington Post, @drbondar
As a working mother of 4 very young children, I don’t have much time to reflect on much – this stage of my life is pretty much dedicated to surviving. I do know that once I decided that I really wanted to start having children (when I was almost finished my PhD) – my life seemed oddly empty. It was as though I realized that something tremendous was missing and I became completely obsessed with wanting them. Now that I have them (yes all 4 of them!) there are many times when I feel completely overwhelmed and exhausted, but I will always remember the feelings of desire to have a family. I know that my life would be empty and incomplete without my lovely babies.
Jeanne Garbarino, Biology Editor at Double X Science and Rockefeller University Postdoc, @JeanneGarb
For five years, I have been a mother. I have learned – and am still learning – some very difficult lessons on time management and prioritization, on choosing my battles wisely, and on being ok when things aren’t exactly perfect (or even decent). But, to be honest, these are all lessons I really needed to have in my life. Though it might seem a bit counterintuitive, the mostly delightful chaos associated with rearing my girls has given me more focus. For me, motherhood is more of a state of being, and it has helped me learn how to not sweat the small stuff (for the most part), to be more mindful of the present, and to think more about the future. Oh, and motherhood also gives me that special golden ticket to buy really cool games and toys (because who isn’t interested in seeing what Doggie Doo is all about), as well as provides a dependable companion for roller coaster rides.
Motherhood had made me stand in my living room as my kids run around me and think how odd it is that I protect these three little persons. Motherhood has made me weep at the sight of children hurt or hungry; has made me rageful at a world where monsters are free; has made me face my own capacity for anger; and it has graced me with random gifts like hysterical laughter over blueberry waffles at the breakfast table.
The four basic categories of molecules for building life are carbohydrates, lipids, proteins, and nucleic acids.
Carbohydrates serve many purposes, from energy to structure to chemical communication, as monomers or polymers.
Lipids, which are hydrophobic, also have different purposes, including energy storage, structure, and signaling.
Proteins, made of amino acids in up to four structural levels, are involved in just about every process of life.
The nucleic acids DNA and RNA consist of four nucleotide building blocks, and each has different purposes.
The longer version
Life is so diverse and unwieldy, it may surprise you to learn that we can break it down into four basic categories of molecules. Possibly even more implausible is the fact that two of these categories of large molecules themselves break down into a surprisingly small number of building blocks. The proteins that make up all of the living things on this planet and ensure their appropriate structure and smooth function consist of only 20 different kinds of building blocks. Nucleic acids, specifically DNA, are even more basic: only four different kinds of molecules provide the materials to build the countless different genetic codes that translate into all the different walking, swimming, crawling, oozing, and/or photosynthesizing organisms that populate the third rock from the Sun.
Big Molecules with Small Building Blocks
The functional groups, assembled into building blocks on backbones of carbon atoms, can be bonded together to yield large molecules that we classify into four basic categories. These molecules, in many different permutations, are the basis for the diversity that we see among living things. They can consist of thousands of atoms, but only a handful of different kinds of atoms form them. It’s like building apartment buildings using a small selection of different materials: bricks, mortar, iron, glass, and wood. Arranged in different ways, these few materials can yield a huge variety of structures.
We encountered functional groups and the SPHONC in Chapter 3. These components form the four categories of molecules of life. These Big Four biological molecules are carbohydrates, lipids, proteins, and nucleic acids. They can have many roles, from giving an organism structure to being involved in one of the millions of processes of living. Let’s meet each category individually and discover the basic roles of each in the structure and function of life.
You have met carbohydrates before, whether you know it or not. We refer to them casually as “sugars,” molecules made of carbon, hydrogen, and oxygen. A sugar molecule has a carbon backbone, usually five or six carbons in the ones we’ll discuss here, but it can be as few as three. Sugar molecules can link together in pairs or in chains or branching “trees,” either for structure or energy storage.
When you look on a nutrition label, you’ll see reference to “sugars.” That term includes carbohydrates that provide energy, which we get from breaking the chemical bonds in a sugar called glucose. The “sugars” on a nutrition label also include those that give structure to a plant, which we call fiber. Both are important nutrients for people.
Sugars serve many purposes. They give crunch to the cell walls of a plant or the exoskeleton of a beetle and chemical energy to the marathon runner. When attached to other molecules, like proteins or fats, they aid in communication between cells. But before we get any further into their uses, let’s talk structure.
The sugars we encounter most in basic biology have their five or six carbons linked together in a ring. There’s no need to dive deep into organic chemistry, but there are a couple of essential things to know to interpret the standard representations of these molecules.
Check out the sugars depicted in the figure. The top-left molecule, glucose, has six carbons, which have been numbered. The sugar to its right is the same glucose, with all but one “C” removed. The other five carbons are still there but are inferred using the conventions of organic chemistry: Anywhere there is a corner, there’s a carbon unless otherwise indicated. It might be a good exercise for you to add in a “C” over each corner so that you gain a good understanding of this convention. You should end up adding in five carbon symbols; the sixth is already given because that is conventionally included when it occurs outside of the ring.
On the left is a glucose with all of its carbons indicated. They’re also numbered, which is important to understand now for information that comes later. On the right is the same molecule, glucose, without the carbons indicated (except for the sixth one). Wherever there is a corner, there is a carbon, unless otherwise indicated (as with the oxygen). On the bottom left is ribose, the sugar found in RNA. The sugar on the bottom right is deoxyribose. Note that at carbon 2 (*), the ribose and deoxyribose differ by a single oxygen.
The lower left sugar in the figure is a ribose. In this depiction, the carbons, except the one outside of the ring, have not been drawn in, and they are not numbered. This is the standard way sugars are presented in texts. Can you tell how many carbons there are in this sugar? Count the corners and don’t forget the one that’s already indicated!
If you said “five,” you are right. Ribose is a pentose (pent = five) and happens to be the sugar present in ribonucleic acid, or RNA. Think to yourself what the sugar might be in deoxyribonucleic acid, or DNA. If you thought, deoxyribose, you’d be right.
The fourth sugar given in the figure is a deoxyribose. In organic chemistry, it’s not enough to know that corners indicate carbons. Each carbon also has a specific number, which becomes important in discussions of nucleic acids. Luckily, we get to keep our carbon counting pretty simple in basic biology. To count carbons, you start with the carbon to the right of the non-carbon corner of the molecule. The deoxyribose or ribose always looks to me like a little cupcake with a cherry on top. The “cherry” is an oxygen. To the right of that oxygen, we start counting carbons, so that corner to the right of the “cherry” is the first carbon. Now, keep counting. Here’s a little test: What is hanging down from carbon 2 of the deoxyribose?
If you said a hydrogen (H), you are right! Now, compare the deoxyribose to the ribose. Do you see the difference in what hangs off of the carbon 2 of each sugar? You’ll see that the carbon 2 of ribose has an –OH, rather than an H. The reason the deoxyribose is called that is because the O on the second carbon of the ribose has been removed, leaving a “deoxyed” ribose. This tiny distinction between the sugars used in DNA and RNA is significant enough in biology that we use it to distinguish the two nucleic acids.
In fact, these subtle differences in sugars mean big differences for many biological molecules. Below, you’ll find a couple of ways that apparently small changes in a sugar molecule can mean big changes in what it does. These little changes make the difference between a delicious sugar cookie and the crunchy exoskeleton of a dung beetle.
Sugar and Fuel
A marathon runner keeps fuel on hand in the form of “carbs,” or sugars. These fuels provide the marathoner’s straining body with the energy it needs to keep the muscles pumping. When we take in sugar like this, it often comes in the form of glucose molecules attached together in a polymer called starch. We are especially equipped to start breaking off individual glucose molecules the minute we start chewing on a starch.
Double X Extra: A monomer is a building block (mono = one) and a polymer is a chain of monomers. With a few dozen monomers or building blocks, we get millions of different polymers. That may sound nutty until you think of the infinity of values that can be built using only the numbers 0 through 9 as building blocks or the intricate programming that is done using only a binary code of zeros and ones in different combinations.
Our bodies then can rapidly take the single molecules, or monomers, into cells and crack open the chemical bonds to transform the energy for use. The bonds of a sugar are packed with chemical energy that we capture to build a different kind of energy-containing molecule that our muscles access easily. Most species rely on this process of capturing energy from sugars and transforming it for specific purposes.
Polysaccharides: Fuel and Form
Plants use the Sun’s energy to make their own glucose, and starch is actually a plant’s way of storing up that sugar. Potatoes, for example, are quite good at packing away tons of glucose molecules and are known to dieticians as a “starchy” vegetable. The glucose molecules in starch are packed fairly closely together. A string of sugar molecules bonded together through dehydration synthesis, as they are in starch, is a polymer called a polysaccharide (poly = many; saccharide = sugar). When the monomers of the polysaccharide are released, as when our bodies break them up, the reaction that releases them is called hydrolysis.
Double X Extra: The specific reaction that hooks one monomer to another in a covalent bond is called dehydration synthesis because in making the bond–synthesizing the larger molecule–a molecule of water is removed (dehydration). The reverse is hydrolysis (hydro = water; lysis = breaking), which breaks the covalent bond by the addition of a molecule of water.
Although plants make their own glucose and animals acquire it by eating the plants, animals can also package away the glucose they eat for later use. Animals, including humans, store glucose in a polysaccharide called glycogen, which is more branched than starch. In us, we build this energy reserve primarily in the liver and access it when our glucose levels drop.
Whether starch or glycogen, the glucose molecules that are stored are bonded together so that all of the molecules are oriented the same way. If you view the sixth carbon of the glucose to be a “carbon flag,” you’ll see in the figure that all of the glucose molecules in starch are oriented with their carbon flags on the upper left.
The orientation of monomers of glucose in polysaccharides can make a big difference in the use of the polymer. The glucoses in the molecule on the top are all oriented “up” and form starch. The glucoses in the molecule on the bottom alternate orientation to form cellulose, which is quite different in its function from starch.
Storing up sugars for fuel and using them as fuel isn’t the end of the uses of sugar. In fact, sugars serve as structural molecules in a huge variety of organisms, including fungi, bacteria, plants, and insects.
The primary structural role of a sugar is as a component of the cell wall, giving the organism support against gravity. In plants, the familiar old glucose molecule serves as one building block of the plant cell wall, but with a catch: The molecules are oriented in an alternating up-down fashion. The resulting structural sugar is called cellulose.
That simple difference in orientation means the difference between a polysaccharide as fuel for us and a polysaccharide as structure. Insects take it step further with the polysaccharide that makes up their exoskeleton, or outer shell. Once again, the building block is glucose, arranged as it is in cellulose, in an alternating conformation. But in insects, each glucose has a little extra added on, a chemical group called an N-acetyl group. This addition of a single functional group alters the use of cellulose and turns it into a structural molecule that gives bugs that special crunchy sound when you accidentally…ahem…step on them.
These variations on the simple theme of a basic carbon-ring-as-building-block occur again and again in biological systems. In addition to serving roles in structure and as fuel, sugars also play a role in function. The attachment of subtly different sugar molecules to a protein or a lipid is one way cells communicate chemically with one another in refined, regulated interactions. It’s as though the cells talk with each other using a specialized, sugar-based vocabulary. Typically, cells display these sugary messages to the outside world, making them available to other cells that can recognize the molecular language.
Lipids: The Fatty Trifecta
Starch makes for good, accessible fuel, something that we immediately attack chemically and break up for quick energy. But fats are energy that we are supposed to bank away for a good long time and break out in times of deprivation. Like sugars, fats serve several purposes, including as a dense source of energy and as a universal structural component of cell membranes everywhere.
Fats: the Good, the Bad, the Neutral
Turn again to a nutrition label, and you’ll see a few references to fats, also known as lipids. (Fats are slightly less confusing that sugars in that they have only two names.) The label may break down fats into categories, including trans fats, saturated fats, unsaturated fats, and cholesterol. You may have learned that trans fats are “bad” and that there is good cholesterol and bad cholesterol, but what does it all mean?
Let’s start with what we mean when we say saturated fat. The question is, saturated with what? There is a specific kind of dietary fat call the triglyceride. As its name implies, it has a structural motif in which something is repeated three times. That something is a chain of carbons and hydrogens, hanging off in triplicate from a head made of glycerol, as the figure shows. Those three carbon-hydrogen chains, or fatty acids, are the “tri” in a triglyceride. Chains like this can be many carbons long.
Double X Extra: We call a fatty acid a fatty acid because it’s got a carboxylic acid attached to a fatty tail. A triglyceride consists of three of these fatty acids attached to a molecule called glycerol. Our dietary fat primarily consists of these triglycerides.
Triglycerides come in several forms. You may recall that carbon can form several different kinds of bonds, including single bonds, as with hydrogen, and double bonds, as with itself. A chain of carbon and hydrogens can have every single available carbon bond taken by a hydrogen in single covalent bond. This scenario of hydrogen saturation yields a saturated fat. The fat is saturated to its fullest with every covalent bond taken by hydrogens single bonded to the carbons.
Saturated fats have predictable characteristics. They lie flat easily and stick to each other, meaning that at room temperature, they form a dense solid. You will realize this if you find a little bit of fat on you to pinch. Does it feel pretty solid? That’s because animal fat is saturated fat. The fat on a steak is also solid at room temperature, and in fact, it takes a pretty high heat to loosen it up enough to become liquid. Animals are not the only organisms that produce saturated fat–avocados and coconuts also are known for their saturated fat content.
The top graphic above depicts a triglyceride with the glycerol, acid, and three hydrocarbon tails. The tails of this saturated fat, with every possible hydrogen space occupied, lie comparatively flat on one another, and this kind of fat is solid at room temperature. The fat on the bottom, however, is unsaturated, with bends or kinks wherever two carbons have double bonded, booting a couple of hydrogens and making this fat unsaturated, or lacking some hydrogens. Because of the space between the bumps, this fat is probably not solid at room temperature, but liquid.
You can probably now guess what an unsaturated fat is–one that has one or more hydrogens missing. Instead of single bonding with hydrogens at every available space, two or more carbons in an unsaturated fat chain will form a double bond with carbon, leaving no space for a hydrogen. Because some carbons in the chain share two pairs of electrons, they physically draw closer to one another than they do in a single bond. This tighter bonding result in a “kink” in the fatty acid chain.
In a fat with these kinks, the three fatty acids don’t lie as densely packed with each other as they do in a saturated fat. The kinks leave spaces between them. Thus, unsaturated fats are less dense than saturated fats and often will be liquid at room temperature. A good example of a liquid unsaturated fat at room temperature is canola oil.
A few decades ago, food scientists discovered that unsaturated fats could be resaturated or hydrogenated to behave more like saturated fats and have a longer shelf life. The process of hydrogenation–adding in hydrogens–yields trans fat. This kind of processed fat is now frowned upon and is being removed from many foods because of its associations with adverse health effects. If you check a food label and it lists among the ingredients “partially hydrogenated” oils, that can mean that the food contains trans fat.
Double X Extra: A triglyceride can have up to three different fatty acids attached to it. Canola oil, for example, consists primarily of oleic acid, linoleic acid, and linolenic acid, all of which are unsaturated fatty acids with 18 carbons in their chains.
Why do we take in fat anyway? Fat is a necessary nutrient for everything from our nervous systems to our circulatory health. It also, under appropriate conditions, is an excellent way to store up densely packaged energy for the times when stores are running low. We really can’t live very well without it.
Phospholipids: An Abundant Fat
You may have heard that oil and water don’t mix, and indeed, it is something you can observe for yourself. Drop a pat of butter–pure saturated fat–into a bowl of water and watch it just sit there. Even if you try mixing it with a spoon, it will just sit there. Now, drop a spoon of salt into the water and stir it a bit. The salt seems to vanish. You’ve just illustrated the difference between a water-fearing (hydrophobic) and a water-loving (hydrophilic) substance.
Generally speaking, compounds that have an unequal sharing of electrons (like ions or anything with a covalent bond between oxygen and hydrogen or nitrogen and hydrogen) will be hydrophilic. The reason is that a charge or an unequal electron sharing gives the molecule polarity that allows it to interact with water through hydrogen bonds. A fat, however, consists largely of hydrogen and carbon in those long chains. Carbon and hydrogen have roughly equivalent electronegativities, and their electron-sharing relationship is relatively nonpolar. Fat, lacking in polarity, doesn’t interact with water. As the butter demonstrated, it just sits there.
There is one exception to that little maxim about fat and water, and that exception is the phospholipid. This lipid has a special structure that makes it just right for the job it does: forming the membranes of cells. A phospholipid consists of a polar phosphate head–P and O don’t share equally–and a couple of nonpolar hydrocarbon tails, as the figure shows. If you look at the figure, you’ll see that one of the two tails has a little kick in it, thanks to a double bond between the two carbons there.
Phospholipids form a double layer and are the major structural components of cell membranes. Their bend, or kick, in one of the hydrocarbon tails helps ensure fluidity of the cell membrane. The molecules are bipolar, with hydrophilic heads for interacting with the internal and external watery environments of the cell and hydrophobic tails that help cell membranes behave as general security guards.
The kick and the bipolar (hydrophobic and hydrophilic) nature of the phospholipid make it the perfect molecule for building a cell membrane. A cell needs a watery outside to survive. It also needs a watery inside to survive. Thus, it must face the inside and outside worlds with something that interacts well with water. But it also must protect itself against unwanted intruders, providing a barrier that keeps unwanted things out and keeps necessary molecules in.
Phospholipids achieve it all. They assemble into a double layer around a cell but orient to allow interaction with the watery external and internal environments. On the layer facing the inside of the cell, the phospholipids orient their polar, hydrophilic heads to the watery inner environment and their tails away from it. On the layer to the outside of the cell, they do the same.
As the figure shows, the result is a double layer of phospholipids with each layer facing a polar, hydrophilic head to the watery environments. The tails of each layer face one another. They form a hydrophobic, fatty moat around a cell that serves as a general gatekeeper, much in the way that your skin does for you. Charged particles cannot simply slip across this fatty moat because they can’t interact with it. And to keep the fat fluid, one tail of each phospholipid has that little kick, giving the cell membrane a fluid, liquidy flow and keeping it from being solid and unforgiving at temperatures in which cells thrive.
Steroids: Here to Pump You Up?
Our final molecule in the lipid fatty trifecta is cholesterol. As you may have heard, there are a few different kinds of cholesterol, some of which we consider to be “good” and some of which is “bad.” The good cholesterol, high-density lipoprotein, or HDL, in part helps us out because it removes the bad cholesterol, low-density lipoprotein or LDL, from our blood. The presence of LDL is associated with inflammation of the lining of the blood vessels, which can lead to a variety of health problems.
But cholesterol has some other reasons for existing. One of its roles is in the maintenance of cell membrane fluidity. Cholesterol is inserted throughout the lipid bilayer and serves as a block to the fatty tails that might otherwise stick together and become a bit too solid.
Cholesterol’s other starring role as a lipid is as the starting molecule for a class of hormones we called steroids or steroid hormones. With a few snips here and additions there, cholesterol can be changed into the steroid hormones progesterone, testosterone, or estrogen. These molecules look quite similar, but they play very different roles in organisms. Testosterone, for example, generally masculinizes vertebrates (animals with backbones), while progesterone and estrogen play a role in regulating the ovulatory cycle.
Double X Extra: A hormone is a blood-borne signaling molecule. It can be lipid based, like testosterone, or short protein, like insulin.
As you progress through learning biology, one thing will become more and more clear: Most cells function primarily as protein factories. It may surprise you to learn that proteins, which we often talk about in terms of food intake, are the fundamental molecule of many of life’s processes. Enzymes, for example, form a single broad category of proteins, but there are millions of them, each one governing a small step in the molecular pathways that are required for living.
Levels of Structure
Amino acids are the building blocks of proteins. A few amino acids strung together is called a peptide, while many many peptides linked together form a polypeptide. When many amino acids strung together interact with each other to form a properly folded molecule, we call that molecule a protein.
For a string of amino acids to ultimately fold up into an active protein, they must first be assembled in the correct order. The code for their assembly lies in the DNA, but once that code has been read and the amino acid chain built, we call that simple, unfolded chain the primary structure of the protein.
This chain can consist of hundreds of amino acids that interact all along the sequence. Some amino acids are hydrophobic and some are hydrophilic. In this context, like interacts best with like, so the hydrophobic amino acids will interact with one another, and the hydrophilic amino acids will interact together. As these contacts occur along the string of molecules, different conformations will arise in different parts of the chain. We call these different conformations along the amino acid chain the protein’s secondary structure.
Once those interactions have occurred, the protein can fold into its final, or tertiary structure and be ready to serve as an active participant in cellular processes. To achieve the tertiary structure, the amino acid chain’s secondary interactions must usually be ongoing, and the pH, temperature, and salt balance must be just right to facilitate the folding. This tertiary folding takes place through interactions of the secondary structures along the different parts of the amino acid chain.
The final product is a properly folded protein. If we could see it with the naked eye, it might look a lot like a wadded up string of pearls, but that “wadded up” look is misleading. Protein folding is a carefully regulated process that is determined at its core by the amino acids in the chain: their hydrophobicity and hydrophilicity and how they interact together.
In many instances, however, a complete protein consists of more than one amino acid chain, and the complete protein has two or more interacting strings of amino acids. A good example is hemoglobin in red blood cells. Its job is to grab oxygen and deliver it to the body’s tissues. A complete hemoglobin protein consists of four separate amino acid chains all properly folded into their tertiary structures and interacting as a single unit. In cases like this involving two or more interacting amino acid chains, we say that the final protein has a quaternary structure. Some proteins can consist of as many as a dozen interacting chains, behaving as a single protein unit.
A Plethora of Purposes
What does a protein do? Let us count the ways. Really, that’s almost impossible because proteins do just about everything. Some of them tag things. Some of them destroy things. Some of them protect. Some mark cells as “self.” Some serve as structural materials, while others are highways or motors. They aid in communication, they operate as signaling molecules, they transfer molecules and cut them up, they interact with each other in complex, interrelated pathways to build things up and break things down. They regulate genes and package DNA, and they regulate and package each other.
As described above, proteins are the final folded arrangement of a string of amino acids. One way we obtain these building blocks for the millions of proteins our bodies make is through our diet. You may hear about foods that are high in protein or people eating high-protein diets to build muscle. When we take in those proteins, we can break them apart and use the amino acids that make them up to build proteins of our own.
How does a cell know which proteins to make? It has a code for building them, one that is especially guarded in a cellular vault in our cells called the nucleus. This code is deoxyribonucleic acid, or DNA. The cell makes a copy of this code and send it out to specialized structures that read it and build proteins based on what they read. As with any code, a typo–a mutation–can result in a message that doesn’t make as much sense. When the code gets changed, sometimes, the protein that the cell builds using that code will be changed, too.
Biohazard!The names associated with nucleic acids can be confusing because they all start with nucle-. It may seem obvious or easy now, but a brain freeze on a test could mix you up. You need to fix in your mind that the shorter term (10 letters, four syllables), nucleotide, refers to the smaller molecule, the three-part building block. The longer term (12 characters, including the space, and five syllables), nucleic acid, which is inherent in the names DNA and RNA, designates the big, long molecule.
DNA vs. RNA: A Matter of Structure
DNA and its nucleic acid cousin, ribonucleic acid, or RNA, are both made of the same kinds of building blocks. These building blocks are called nucleotides. Each nucleotide consists of three parts: a sugar (ribose for RNA and deoxyribose for DNA), a phosphate, and a nitrogenous base. In DNA, every nucleotide has identical sugars and phosphates, and in RNA, the sugar and phosphate are also the same for every nucleotide.
So what’s different? The nitrogenous bases. DNA has a set of four to use as its coding alphabet. These are the purines, adenine and guanine, and the pyrimidines, thymine and cytosine. The nucleotides are abbreviated by their initial letters as A, G, T, and C. From variations in the arrangement and number of these four molecules, all of the diversity of life arises. Just four different types of the nucleotide building blocks, and we have you, bacteria, wombats, and blue whales.
RNA is also basic at its core, consisting of only four different nucleotides. In fact, it uses three of the same nitrogenous bases as DNA–A, G, and C–but it substitutes a base called uracil (U) where DNA uses thymine. Uracil is a pyrimidine.
DNA vs. RNA: Function Wars
An interesting thing about the nitrogenous bases of the nucleotides is that they pair with each other, using hydrogen bonds, in a predictable way. An adenine will almost always bond with a thymine in DNA or a uracil in RNA, and cytosine and guanine will almost always bond with each other. This pairing capacity allows the cell to use a sequence of DNA and build either a new DNA sequence, using the old one as a template, or build an RNA sequence to make a copy of the DNA.
These two different uses of A-T/U and C-G base pairing serve two different purposes. DNA is copied into DNA usually when a cell is preparing to divide and needs two complete sets of DNA for the new cells. DNA is copied into RNA when the cell needs to send the code out of the vault so proteins can be built. The DNA stays safely where it belongs.
RNA is really a nucleic acid jack-of-all-trades. It not only serves as the copy of the DNA but also is the main component of the two types of cellular workers that read that copy and build proteins from it. At one point in this process, the three types of RNA come together in protein assembly to make sure the job is done right.
Prenatal care and treatment access are big factors.
By Laura Newman
Last week, the media got all excited about the possibility of a cure for HIV perinatal transmission. What was lacking was the recognition that the public remains largely ignorant about HIV in pregnant women. Yet with good wellness care, prevention, HIV testing, and medication,HIV transmission from mother to child can be close to zero. The public needs to know that women who are pregnant and HIV positive can also live good-quality lives, as can their children.
Thanks to Dr. Judy Levison, an obstetrician/gynecologist whose career centers on caring for HIV-pregnant women, I began to learn how scientific advancements in HIV-care make it possible for pregnant women with HIV and HIV-positive men to have children and not transmit the virus to their newborns. In the midst of this learning experience, I found out that a young woman I know, “Angela*,” was HIV positive and wanted to plan a pregnancy. I was shocked; I knew plenty of gay men with HIV, but rarely had I met a woman who had contracted the virus. Planning a pregnancy while being infected with HIV was something that I couldn’t imagine.
“Angela” is married and has lived with HIV for some years, with a low viral load by taking good care of herself and taking recommended antiretroviral therapy, when needed. She sought artificial insemination, one of several options available to HIV-affected couples. It worked. When she was planning her pregnancy, her parents were resistant. They worried that even though she is healthy now, that might change. They couldn’t imagine being saddled with taking care of a young child. Her parents’ resistance reminded me of the old coming-out stories we used to hear and how parents adapted to learning their child is gay. To their credit, both parents soon rose to the occasion. Angela and her spouse have a healthy toddler, and the grandparents love spending time with him.
Angela’s story isn’t everyone’s story. The hubbub at the recent 20th Conference on Retroviruses and Opportunistic Infections was not on the “functional cure” of the baby born to a pregnant woman with HIV, but on why, in this day and age, the mother doesn’t seem to have received the recommended prenatal care and antiretroviral therapy herself. Under what circumstances did she deliver? How did mom and baby get lost in the healthcare system? It’s far too easy to be captivated by a potential breakthrough and forget that plenty of people don’t get access to basic science-backed care that prevents HIV transmission in the first place.
As I describe below and as Angela’s experience illustrates, a lot of evidence shows that it is very safe for women with HIV to get pregnant, have healthy babies, and not transmit HIV to their children. Unfortunately, for many pregnant women with HIV, harsh judgments and inaccurate assumptions often carry the day. Let’s just say that HIV-positive moms and their kids have not earned the acceptance allotted to, say, a Magic Johnson, who has had HIV for decades, and with good HIV and wellness care, lives a good-quality life.
These inroads in science-based HIV prevention and care that have helped Johnson so much lag behind in poor and minority communities in the United States and low-resource countries around the world. HIV disproportionally affects African-Americans in the United States, and access to care, Medicaid cuts, and poverty reduce the chance that many people in need will receive good state-of-the-art prevention (regular testing, practicing safe sex, not sharing drug needles) and wellness care. Perinatal transmission could well rise in these communities.
Facing down ignorance
At first, being pregnant was not easy for Angela — not because her pregnancy was hard (it was not) — but because of the uneasiness some of her coworkers expressed about her becoming pregnant as an HIV-positive woman. Even though Angela worked in healthcare, some of her coworkers thought she had no business being pregnant. When she complained to her supervisor, the manager urged Angela to take it upon herself to educate staff about scientifically proven treatments for pregnant women with HIV that help moms stay well and prevent transmission to the baby. Angela asked instead for an in-service training, which was scheduled. Her colleagues’ attitudes turned around after the in-service.
It meant a lot to her to change the culture.
Angela had a normal term delivery, gave birth to a healthy baby, who is now a toddler, with no sign of HIV infection. Angela’s viral load remains undetectable. They are living healthy, high-quality lives like many other families, moms, and children.
The parents and prenatal planning
The ideal in the setting of HIV infection is that both partners are involved in preconception planning. Prevention of transmission of HIV from an HIV-positive father to an HIV-negative mom and fetus is now possible. The door is now open to HIV-positive men and women who want families but have HIV. Any plans they had to become parents have not simply vanished.
HIV research has advanced to the point that we now know that if HIV-positive individuals work with knowledgeable medical providers and have good access to proven practices, parents and children do quite well. Essential practices include:
Before trying to conceive, people should take antiretroviral drugs and have their infection under control, shown by a low viral load or undetectable levels of the virus (“undetectable” levels vary, depending on the lab) in their blood;
Couples are instructed to have unprotected sex only when the woman is ovulating. Current guidelines recommend using an ovulation prediction kit, which you can purchase at most drugstores.
Artificial insemination is another option that HIV-affected couples are using, as Angela did.
HIV testing is recommended routinely for all pregnant women, as well as for all non-pregnant adults and teens.
If a woman learns during her pregnancy for the first time that she is HIV infected, she can work with her healthcare provider to stay healthy, prevent mother-to-child transmission, and prevent passing HIV to her partner.
In general, people infected with HIV who are not pregnant begin taking anti-HIV medications when their CD4 counts fall below 500 cells/mm3 (HIV targets these immune cells and destroys them, compromising a person’s immunity). The medication regimen during pregnancy depends on whether or not you are taking medication to improve your own health or just your baby’s. In many cases, healthy women delay starting antiretroviral medication until the second trimester, which is when all women should be on HIV medication. However, HIV medication and interactions with other drugs and the fetus are complicated and require consultation with a physician. If women are diagnosed later in a pregnancy, they should start HIV drugs then. You can find detailed recommendations here.
During childbirth, women whose viral loads are still undetectable can have normal vaginal deliveries. However, according to the National Institutes of Health and other authorities, scheduled cesarean delivery at 38 weeks of gestation is recommended to reduce perinatal transmission of HIV for women with HIV-RNA levels >1,000 copies/mL or unknown HIV levels near the time of delivery, regardless of whether they were taking recommended antiretroviral drugs during pregnancy. The guidelines state that when there is a low rate of transmission (viral loads lower than 1000 copies/mL), the benefits of a scheduled c-section are unclear. Dr. Levison, an obstetrician/gynecologist at Baylor College of Medicine, Houston, TX, says that in her practice, women rarely need a cesarean section.
The newborn child
In the United States, breastfeeding is discouraged because HIV can be transmitted in breast milk. According to the Centers for Disease Control and Prevention (CDC), the risk for HIV transmission goes up as much as 45%. However, the topic of breastfeeding remains controversial. In healthy women with no HIV history, the broad consensus is that breastfeeding is best, giving babies excellent nutrition and helping the infant bond with mom. And many parts of the world have problems with sanitation and dirty water, making breastfeeding preferable to mixing formula. Outside of the US, according to Levison, in the UK, breastfeeding guidelines are more liberal. Furthermore, in some cultures, women are afraid not to breastfeed for fear that they will be outed as having an HIV infection, according to Levison, so many treating physicians adapt practice to the culture, preferences of the mom. Internationally, for example, in Africa, women often breastfeed and remain on antiretroviral drugs during that time. Formula is also costly. In the US, poor moms are eligible for formula through the federal Women’s Infants and Children’s nutritional support program.
Besides breastfeeding, HIV-positive moms need to know that pre-chewing of food before feeding baby is a transmission risk.
As soon as a woman goes into labor and during childbirth, the infantmust begin a six-week course of the antiretroviral medication zidovudine (AZT). Current guidelines also state that the baby should be tested for HIV at 14 to 21 days, at 1 to 2 months, and again at 4 to 6 months. If the viral load remains undetectable after two tests, the baby is considered to not have gotten HIV.
Resolving resource disparities
The moms, dads, and kids with HIV have enormous potential to live healthy lives for decades on proven antiretroviral drugs.
In fact, a December 2012 CDC Fact Sheet states that the number of women with HIV giving birth in the United States increased approximately 30% from 6,000 to 7,000 in 2000 to 8700 in 2006. During that same time frame, the estimated number of perinatal infections per year in all 50 states and 5 dependent areas continued to decline.
It’s not all good news, though, because of marked disparities in resource allocation and pre- and perinatal care. According to CDC data, 63% of perinatal infections were in blacks/African-Americans; 22% were in Hispanics/Latinos, and 13% were in whites. That leaves a lot of work to be done in enhancing targeted prevention programs.
Another recent milestone is that the US Preventive Services Task Force is finally about to endorse universal HIV testing, long after the CDC backed such a move in 2006. This milestone is important to because it is also linked to health reform. All public and private health plans are required to provide coverage for U.S. Preventive Services Task Force-recommended preventive services without patient copayments.
With this availability, perhaps women might learn about an HIV infection before they become pregnant, giving them time to have their own treatment in place before it is too late to protect the baby. The case report of the baby cured of HIV gives a lot of hope, but even more preferable would be preventing HIV infection in the first place, through safe sex and not exchanging needles. Once people become infected, for whatever reason, their lives should no longer be viewed as if they are at in a holding pattern until death.
The world needs to know that just like every other mom, dads and pregnant women with HIV can parent children, stay healthy, and not transmit the virus to their babies. Paramount in this is universal HIV testing for adults and teens, prevention programs, and ensuring scientifically proven treatment of the mother before, during, and after her pregnancy.
Scene 1: Two fathers encounter each other at a Boy Scout meeting. After a little conversation, one reveals that his son won’t be playing football because of concerns about head injuries. The other father reveals that he and his son love football, that they spoke with their pediatrician about it, and that their son will continue with football at least into middle school. There’s a bit of wary nodding, and then, back to the Pinewood Derby.
Scene 2: Two mothers meet on a playground. After a little conversation about their toddlers, one mother mentions that she still breastfeeds and practices “attachment parenting,” which is why she has a sling sitting next to her. The other mother mentions that she practiced “cry it out” with her children but that they seem to be doing well and are good sleepers. Then one of the toddlers begins to cry, obviously hurt in some way, and both mothers rush over together to offer assistance.
Scene 3: In the evening, one of these parents might say to a partner, “Can you believe that they’re going to let him play football?” or “I can’t believe they’re still breastfeeding when she’s three!” Sure. They might “judge” or think that’s something that they, as parents, would never do.
But which ones are actually involved in a war?
War. What is it good for?
I can’t answer that question, but I can tell you the definition of ‘war’: “a state of armed conflict between different nations or states or different groups within a nation or state.” Based on this definition and persistent headlines about “Mommy Wars,” you might conclude that a visit to your local playground or a mom’s group outing might require decking yourself out cap-á-pie in Kevlar. But the reality on the ground is different. There is no war. Calling disputes and criticisms and judgments about how other people live “war” is like calling a rowboat on a pond the Titanic. One involves lots of energy release just to navigate relatively placid waters while the other involved a tremendous loss of life in a rough and frigid sea. Big difference.
I’m sure many mothers can attest to the following: You have friends who also are mothers. I bet that for most of us, those friends represent a spectrum of attitudes about parenting, education, religion, Fifty Shades of Grey, recycling, diet, discipline, Oprah, and more. They also probably don’t all dress just like you, talk just like you, have the same level of education as you, same employment, same ambitions, same hair, or same toothpaste. And I bet that for many of us, in our interactions with our friends, we have found ourselves judging everything from why she insists on wearing those shoes to why she lets little Timmy eat Pop Tarts. Yet, despite all of this mental observation and, yes, judging, we still manage to get along, go out to dinner together, meet at one another’s homes, and gab our heads off during play dates.
That’s not a war. That’s life. It’s using our brains as shaped by our cultural understanding and education and rejection or acceptance of things from our own upbringing and talks with medical practitioners and books we’ve read and television shows we’ve watched and, for some of us, Oprah. Not one single friend I have is a cookie cutter representation of me or how I parent. Yet, we are not at war. We are friends. Just because people go online and lay out in black and white the critiques that are in their heads doesn’t mean “war” is afoot. It means expressing the natural human instinct to criticize others in a way that we think argues for Our Way of Doing Things. Online fighting is keeping up with the virtual Joneses. In real life, we are friends with the Joneses, and everyone tacitly understands what’s off limits within the boundaries of that friendship. That’s not war. It’s friendly détente.
The reality doesn’t stop the news media from trying to foment wars, rebellions, and full-on revolutions with provocative online “debates” and, lately, magazine covers. The most recent, from Time, features a slender mother, hand on cocked hip, challenging you with her eyes as she nurses her almost-four-year-old son while he stands on a chair. As Time likely intended, the cover caused an uproar. We’ve lampooned it ourselves (see above).
But the question the cover asks in all caps, “Are you mom enough?” is even more manipulative than the cover because it strikes at the heart of all those unspoken criticisms we think–we know–other women have in their heads about our parenting. What we may not consider is that we, too, are doing the same, and still… we are not actually at war. We’re just women, judging ourselves and other women, just like we’ve done since the dawn of time. It’s called “using your brain.” Inflating our interactions and fairly easily achieved parental philosophy détentes to “war” caricatures us all as shrieking harpies, incapable of backing off and being reasonable.
The real question to ask isn’t “Are you mom enough?” In fact, it’s an empty question because there is no answer. Your parenting may be the most perfect replica of motherhood since the Madonna (the first one), yet you have no idea how that will manifest down the road in terms of who your child is or what your child does. Whether you’re a Grizzly or a Tiger or a Kangaroo or a Panda mother, there is no “enough.”
So, instead of asking you “Are you mom enough?”, in keeping with our goal of bringing women evidence-based science, we’ve looked at some of the research describing what might make a successful parent–child relationship. Yes, the answer is about attachment, but not necessarily of the physical kind. So drop your guilt. Read this when you have time. Meanwhile, do your best to connect with your child, understand your child, and respond appropriately to your child.
Why? Because that is what attachment is–the basic biological response to a child’s needs. If you’re not a nomad or someone constantly on the move, research suggests that the whole “physically attached to me” thing isn’t really a necessary manifestation of attachment. If you harken to it and your child enjoys it (mine did not) and it works for you without seeming like, well, an albatross around your neck, go for it.
What is attachment?
While attachment as a biological norm among primates has been around as long as primates themselves, humans are more complicated than most primates. We have theories. Attachment theory arose from the observations of a couple of human behaviorists or psychologists (depending on whom you ask), John Bowlby and Mary Ainsworth. Bowlby derived the concept of attachment theory, in which an infant homes in on an attachment figure as a “safe place.” The attachment figure, usually a parent, is the person who responds and is sensitive to the infant’s needs and social overtures. That parent is typically the mother, and disruption of this relationship can have, as most of us probably instinctively know, negative effects.
Bowlby’s early approach involved the mother’s having an understanding of the formational experiences of her own childhood and then translating that to an understanding of her child. He even found that when he talked with parents about their own childhoods in front of their children, the result would be clinical breakthroughs for his patients. As he wrote,
Having once been helped to recognize and recapture the feelings which she herself had as a child and to find that they are accepted tolerantly and understandingly, a mother will become increasingly sympathetic and tolerant toward the same things in her child.
Later studies seem to bear out this observation of a connection to one’s childhood experiences and more connected parenting. For example, mothers who are “insightful” about their children, who seek to understand the motivations of their children’s behavior, positively influence both their own sensitivity and the security of their infant’s attachment to them.
While Bowlby’s research focused initially on the effects of absolute separation between mother and child, Mary Ainsworth, an eventual colleague of Bowlby, took these ideas of the need for maternal input a step further. Her work suggested to her that young children live in a world of dual and competing urges: to feel safe and to be independent. An attachment figure, a safe person, is for children an anchor that keeps them from become unmoored even as they explore the unknown waters of life. Without that security backing them up, a child can feel always unmoored and directionless, with no one to trust for security.
Although he was considered an anti-Freudian rebel, Bowlby had a penchant for Freudian language like “superego” and referred to the mother as the “psychic organizer.” Yet his conclusions about the mother–child bond resonate with their plain language:
The infant and young child should experience a warm, intimate, and continuous relationship with his mother (or permanent mother substitute) in which both find satisfaction and enjoyment.
You know, normal biological stuff. As a side note, he was intrigued by the fact that social bonds between mother and offspring in some species weren’t necessarily tied to feeding, an observation worth keeping in mind if you have concerns about not being able to breastfeed.
The big shift here in talking about the mother–child relationship was that Bowlby was proposing that this connection wasn’t some Freudian libidinous communion between mother and child but instead a healthy foundation of a trust relationship that could healthily continue into the child’s adulthood.
Ainsworth carried these ideas to specifics, noting in the course of her observations of various groups how valuable a mother’s sensitivity to her child’s behaviors were in establishing attachment. In her most famous study, the “Baltimore study” [PDF], she monitored 26 families with new babies. She found that “maternal responsiveness” in the context of crying, feeding, playing, and reciprocating seemed to have a powerful influence on how much a baby cried in later months, although some later studies dispute specific influences on crying frequencies.
Ainsworth also introduced the “Strange Situation” lab test, which seems to have freaked people out when it first entered the research scene. In this test, over the course of 20 minutes, a one-year-old baby is in a room full toys, first with its mother, then with mother and a strange woman, then with the stranger only (briefly), then with the mother, and then alone before the stranger and then the mother return. The most interesting findings of the study came from when the mother returned after her first absence, having left the baby alone in the room with a stranger. Some babies seemed quite angry, wanting to be with their mothers but expressing unhappiness with her at the same time and physically rejecting her.
From her observations during the Strange Situation, Ainsworth identified three types of attachment. The first was “Secure,” which, as its name implies, suggested an infant secure and comfortable with an attachment figure, a person with whom the infant actively seeks to interact. Then there’s the insecure–avoidant attachment type, in which an infant clearly is not interested in being near or interacting with the attachment figure. Most complex seems to be the insecure–resistant type, and the ambivalence of the term reflects the disconnected behavior the infant shows, seeming to want to be near the attachment figure but also resisting, as some of the unhappy infants described above behaved in the Strange Situation.
Within these types are now embedded various subtypes, including a disorganized–disoriented type in which the infant shows “odd” and chaotic behavior that seems to have no distinct pattern related to the attachment figure.
As you read this, you may be wondering, “What kind of attachment do my child and I have?” If you’re sciencey, you may fleetingly even have pondered conducting your own Strange Situation en famille to see what your child does. I understand the impulse. But let’s read on.
What are the benefits of attachment?
Mothers who are sensitive to their children’s cues and respond in ways that are mutually satisfactory to both parties may be doing their children a lifetime of favors, in addition to the parental benefit of a possibly less-likely-to-cry child. For example, a study of almost 1300 families looked at levels of cortisol, the “stress” hormone, in six-month-old infants and its association with maternal sensitivity to cues and found lower levels in infants who had “more sensitive” mothers.
Our understanding of attachment and its importance to infant development can help in other contexts. We can apply this understanding to, for example, help adolescent mothers establish the “secure” level of attachment with their infants. It’s also possibly useful in helping women who are battling substance abuse to still establish a secure attachment with their children.
On a more individual level, it might help in other ways. For example, if you want your child to show less resistance during “clean-up” activities, establishing “secure attachment” may be your ticket to a better-looking playroom.
More seriously, another study has found that even the way a mother applies sensitivity can be relevant. Using the beautiful-if-technical term ‘dyads’ to refer to the mother–child pair, this study included maternal reports of infant temperament and observations of maternal sensitivity to both infant distress and “non-distress.” Further, the authors assessed the children behaviorally at ages 24 and 36 months for social competence, behavioral problems, and typicality of emotional expression. They found that a mother’s sensitivity to an infant’s distress behaviors was linked to fewer behavioral problems and greater social competence in toddlerhood. Even more intriguing, the child’s temperament played a role: for “temperamentally reactive” infants, a mother’s sensitivity to distress was linked to less dysregulation of the child’s emotional expression in toddlerhood.
And that takes me to the child, the partner in the “dyad”
You’re not the only person involved in attachment. As these studies frequently note, you are involved in a “dyad.” The other member of that dyad is the child. As much as we’d like to think that we can lock down various aspects of temperament or expression simply by forcing it with our totally excellent attachment skills, the child in your dyad is a person, too, who arrived with a bit of baggage of her own.
And like the study described above, the child’s temperament is a key player in the outcome of the attachment tango. Another study noted that multiple factors influence “attachment quality.” Yes, maternal sensitivity is one, but a child’s native coping behaviors and temperament also seem to be involved. So, there you have it. If you’re feeling like a parental failure, science suggests you can quietly lay at least some of the blame on the Other in your dyad–your child. Or, you could acknowledge that we’re all human and this is just part of our learning experience together.
What does attachment look like, anyway?
Dr. William Sears took the concept of attachment and its association with maternal sensitivity to a child’s cues and security and… wrote a book that literally translated attachment as a physical as well as emotional connection. This extension of attachment–which Sears appends to every aspect of parenting, from pregnancy to feeding to sleeping–has become in the minds of some parents a prescriptive way of doing things with benefits that exclude all other parenting approaches or “philosophies.” It also involves the concept of “baby wearing,” which always brings up strange images in my mind and certainly takes outré fashion to a whole new level. In reality, it’s just a way people have carried babies for a long time in the absence of other easy modes of transport.
When I was pregnant with our first child and still blissfully ignorant about how little control parents have over anything, I read Sears’ book about attachment parenting. Some of it is common-sense, broadly applicable parenting advice: respond to your child’s needs. Some of it is simply downright impossible for some parent–child dyads, and much of it is based on the presumption that human infants in general will benefit from a one-size-fits-all sling of attachment parenting, although interpretations of the starry-eyed faithful emphasize that more than Sears does.
Because much of what Sears wrote resonated with me, we did some chimeric version of attachment parenting–or, we tried. The thing is, as I noted above, the infant has some say in these things as well. Our oldest child, who is autistic, was highly resistant to being physically attached much of the time. He didn’t want to sleep with us past age four months, and he showed little interest in aspects of attachment parenting like “nurturing touch,” which to him was seemingly more akin to “taser touch.” We ultimately had three sons, and in the end, they all preferred to sleep alone, each at an earlier and earlier age. The first two self-weaned before age one because apparently, the distractions of the sensory world around them were far more interesting than the same boring old boob they kept seeing immediately in front of their faces. Our third was unable to breastfeed at all.
So, like all parents do, we punted, in spite of our best laid plans and intentions. Our hybrid of “attachment parenting” could better be translated into “sensitivity parenting,” because our primary focus, as we punted and punted and punted our way through the years, was shifting our responses based on what our children seemed to need and what motivated their behaviors. Thus, while our oldest declined to sleep with us according to the attachment parenting commandment, he got to sleep with a boiled egg because that’s what he wanted. Try to beat that, folks, and sure, bring on the judging.
The Double X Science Sensitivity Parenting (TM) cheat sheet.
What does “sensitive” mean?
And finally, the nitty-gritty bullet list you’ve been waiting for. If attachment doesn’t mean slinging your child to your body until you’re lumbar gives out or the child receives a high-school diploma, and parenting is, indeed, one compromise after another based on the exigencies of the moment, what consistent tenets can you practice that meet the now 60-year-old concept of “secure” attachment between mother and child, father and child, or mother or father figure and child? We are Double X Science, here to bring you evidence-based information, and that means lists. The below list is an aggregate of various research findings we’ve identified that seem reasonable and reasonably supported. We’ve also provided our usual handy quick guide for parents in a hurry.
Plan ahead. We know that life is what happens while you’re planning things, but… life does happen, and plans can at least serve as a loose guide to navigation. So, plan that you will be a parent who is sensitive to your child’s needs and will work to recognize them.
Practice emotion detection. Work on that. It doesn’t come easily to everyone because the past is prologue to what we’re capable of in the present. Ask yourself deliberately what your child’s emotion is communicating because behavior is communication. Be the grownup, even if sometimes, the wailing makes you want your mommy. As one study I found notes, “Crying is an aversive behavior.” Yes, maybe it makes you want to cover your ears and run away screaming. But you’re the grownup with the analytical tools at hand to ask “Why” and seek the answer.
Have infant-oriented goals. If you tend to orient your goals in your parent–child dyad toward a child-related benefit (relieve distress) rather than toward a parent-oriented goal (fitting your schedule in some way), research suggests that your dyad will be a much calmer and better mutually adapted dyad.
Trust yourself and keep trying. If your efforts to read your child’s feelings or respond to your child’s needs don’t work right away, don’t give up, don’t read Time magazine covers, and don’t listen to that little voice in your head saying you’re a bad parent or the voice in other people’s heads screaming that at you. Just keep trying. It’s all any of us can do, and we’re all going to screw this up here and there.
Practice behaviors that are supportive of an infant’s sensory needs. For example, positive inputs like a warm voice and smiling are considered more effective than a harsh voice or being physically intrusive. Put yourself in your child’s place and ask, How would that feel? That’s called empathy.
Engage in reciprocation. Imitating back your infant’s voice or faces, or showing joint attention–all forms of joint engagement–are ways of telling an infant or young child that yes, you are the anchor here, the one to trust, and really good time, to boot. Allowing this type of attention to persist as long as the infant chooses rather than shifting away from it quickly is associated with making the child comfortable with independence and learning to regulate behaviors.
Talk to your child. We are generally a chatty species, but we also need to learn to chat. “Rich language input” is important in early child development beginning with that early imitation of your infant’s vocalizations.
Lather, rinse, repeat, adjusting dosage as necessary based on age, weight, developmental status, nanosecond-rate changes in family dynamics and emotional conditions, the teen years, and whether or not you have access to chocolate. See? This stuff is easy.
As you read these lists and about research on attachment, you’ll see words like “secure” and “warm” and “intimate” and “safe.” Are you doing this for your child or doing your best to do it? Then you are, indeed, mom enough, whether you wear your baby or those shoes or both. That doesn’t mean that when you tell other women the specifics of your parenting tactics, they won’t secretly be criticizing you. Sure, we’ll all do that. And then a toddler will cry, we’ll drop it, and move on to mutually compatible things.
Yes, if we’re being honest, it makes most of us feel better to think that somehow, in some way, we’re kicking someone else’s ass in the parenting department. Unfortunately for that lowly human instinct, we’re all parenting unique individuals, and while we may indeed kick ass uniquely for them, our techniques simply won’t extend to all other children. It’s not a war. It’s human… humans raising other humans. Not one thing we do, one philosophy we follow, will guarantee the outcome we intend. We don’t even need science, for once, to tell us that.
Leah Gerber is an Associate Professor of ecology at Arizona State University. Her research is motivated by a desire to connect academic pursuits in conservation science to decision tools and effective conservation solutions. This approach includes a solid grounding in natural history and primary data collection, quantitative methods and an appreciation for the interactions between humans and the environment. She is keenly aware of the need for the communication of scientific results to the public and to government and non-governmental agencies. This communication is essential for the translation of scientific results into tenable conservation solutions.
DXS: First, can you give me a quick overview of what your scientific background is and your current connection to science?
LG: I learned about ecology and environmental conservation as an undergraduate and quickly became motivated to do science that impacted the real world of conservation. Learning about the impacts of humans on nature was a wake-up call for me, and inspired me to channel my feeling of concern for the demise of nature in a positive way.
From there, I have walked the tightrope between science and policy. After getting my undergraduate degree in environmental biology, I wanted to do more than just the science. So I enrolled in a masters program at the University of Washington – an interdisciplinary program called Marine Affairs. It was a great experience, but I wanted to have more substance to my science background – I wanted to know how to do the science in addition to how to apply the science.
This compelled me to enter a PhD at the University of Washington, which was largely funded by NOAA. My thesis involved trying to figure out how to make decisions about endangered species – how to determine which were endangered and which were threatened. This was a perfect project given my interest in developing tools to solve problems. After finishing my PhD, I did a postdoc at the National Center for Ecological Analysis and Synthesis (NCEAS) and developed approaches for marine reserve design and endangered species recovery. I was at NCEAS for three years before starting on the tenure track at Arizona State University. I’ve been at ASU for about 10 years now.
A major theme in my work has remained constant – that is, how to use the information we are generating in the natural and social sciences to better manage our natural world. Pre-tenure I focused a lot more on doing the science, publishing in good journals, and hoping that it made its way into good policy. Now that I am midcareer, meaning that I have a good amount of papers and tenure, I am enjoying the opportunity to work with practitioners outside of academia. For instance, I just got off the phone with someone from National Geographic regarding my recent publicationon seafood health and sustainability. In that study, we performed an analysis regarding seafood in the context of health and sustainability, to answer simple questions like, what to order when out to sushi? How do we educate about health benefits and risks? We will be organizing a workshop to help restaurant chains, grocery stores, as well as environmental NGOs identify a path forward in informing consumers about healthy and sustainable seafood choices. As a tenured professor, I feel fortunate to have the opportunity to work at the science-policy interface and to give society some science that is truly applicable.
DXS: It is too bad that you have to wait until you are more established and have tenure to go out and engage with the public, because this type of thing is just so important!
LG: Yes, I agree. There isn’t a clear path in academia when it comes to public engagement. But in recent years I have felt optimistic – the landscape within academia is starting to change, and at ASU this change is noticeable. We have a fabulous president, Michael Crow, who has really transformed ASU from just another state institution to a leader in sustainability. Part of this is the establishment of the Global Institute for Sustainability, and one of Michael Crow’s mantras is “community embeddedness.” He is really on board with this type of thing and I have seen evidence of his commitment trickle down throughout the University. For instance, when I first arrived, I had to justify and explain why I was serving on these federal recovery teams for endangered species. Now I feel that there is no justification needed. Developing solutions is not only so important for society, but should also be a key aspect of what we do at Universities.
DXS: We were introduced by another fantastic science communicator, Liz Neeley, who you met at a communications workshop. Why is it important to take part in this type of training?
LG: I met the Fantastic and Fashionable Liz through the Leopold Leadership Program, offered through the Woods Institute for the Environment at Stanford University. The Leopold Leadership training was the best professional development experience of my career, and has made me a better translator and communicator of science to policy. Pre-Leopold, I had little training in communications, and there I was, in a teaching position where I taught hundreds students. I thought to myself, well, how do I do this? The Leopold experience has solidified my commitment to teaching students about communication and engaging in policy.
One development emerging from this training is a science communication symposium at the AAAS meeting. Elena Bennett and I are giving a talk on overcoming institutional barriers for community engagement, and we will address the issues head on. We put out a survey asking others if they faced institutional barriers, and how they might work to engage more.
DXS: What ways do you express yourself creatively that may not have a single thing to do with science?
LG: I have 2 young kids, a 3yo and a 7yo. Being a mom helps me keep it real - I love that I get to enjoy the awe of discovering the world with my girls. We just got a puppy this weekend and we are having fun dressing her up and painting her nails (only partly joking). Other things that I do that are creative – truthfully, I am uninteresting – I don’t bake bread or go to the opera. I just work and take care of my kids. I practice yoga for my own sanity and also love to work in the garden. Doing these things gives me a reason to pause and step off the treadmill of keeping up with everything.
DXS: Do you find that your scientific background informs the creativity you have with your kids or your yoga practice, even though what you do may not specifically be scientific?
LG: I think there is synergy with my science and my kids and my yoga practice in helping me to accept things and be mindful – but not in any conscious way. For instance, when doing my science, the type A person that I am, I have an inclination to keep pushing, pushing, pushing. My kids and my yoga help me to shift gears and accept that things are going to happen when they happen. I try to let the kids be kids, including the associated chaos, and accept that this is a snapshot in time that they will be little. Now I find joy in that chaos. Having kids and yoga gives me a little more perspective, and the knowledge that things aren’t lined up and neatly placed in a box. It rounds me out.
DXS: Are your kids are major influencers in your career?
LG: My first child, Gabriella, was born just after I submitted my application for tenure – so it was good timing. And I was able to slow down. I quickly realized that I wasn’t able to work a 60+hour week. Before kids, I lived to work. Now, I work to live. I absolutely love my job and I feel so lucky that I have a career that I believe in and that I am actually paid to do it – it’s not just a hobby. But having kids made me chill out a little. If I get a paper rejected, I can let it go instead of lamenting about it for weeks. It has made me healthier. I don’t necessarily know if it has had positive impact on my career – time will tell. While my publication rate may be slightly smaller, I think my work now has different dimensions, and greater depth.
I am still pretty passionate about my work, and my kids know what I do and are proud of it. They share it with their classmates, and take every opportunity to wax poetic about how their mom saves animals in the ocean. They also have a built in conservation effort – my 7YO gets irritated when she can’t find a compost bin, and her new thing is to only fill her cup half way because she will only drink a little bit of water.
DXS: When you decided to have children, did your colleagues view you differently? Did they consider that you were sending your career down the tubes or was it a supportive environment?
LG: I honestly had a really positive experience. I can’t think of any negative sentiments from my colleagues, and they were actually really supportive. For instance, when I was pregnant with my first daughter, ASU did not have a maternity leave policy. Before that, you would have to take sick leave. So my colleague worked within the parameters of the unit to give me maternity leave. And then with my second daughter, our new president had established a maternity policy.
The support of my colleagues at ASU has made me feel loyal to my institution. Normally, I am loyal to people and not institutions, but overall, the support has been fabulous. Of course, with having the kids in each case, I did decline a lot of invitations – some pretty significant ones – but I did not have a desire to drag a newborn to give a talk, especially when I was nursing. And it was hard for me to do this at times, especially given my career driven nature, and I had to learn to accept that there would be other opportunities.
I had to shift it down a notch and realize that the world wasn’t going to freeze over, and that I could shift it back to high gear later. With “mommy brain”, I knew I wasn’t going to be at the top of my game at that point in my life. But I have incredible role models. Most notable is Jane Lubchenco, currently the Director of the National Oceanic and Atmospheric Administration. During the first part of her career, she shared a position with her husband – each did 50% – and they did that on purpose so they’d be able to enjoy having children and effectively take care of them. Now, she is in the National Academy, is having major scientific impacts, and she did it all despite having kids. If she can do it, why cant the rest of us?
DXS: Given your experiences as a researcher, as a mother, and now as a major science communicator, do you feel that your ability to talk to people has evolved?
LG: Absolutely. I think that the Leopold Training Program, which selects 20 academics from North America to participate in retreats to learn how to be better communicate and lead, has re-inspired all who attended. It has recharged our batteries and allowed us to make realizations that doing good science and putting it out there via scientific publication is just not enough. We also have to push it out there and make it available to a broader, more diverse population. As part of the training, we also learned about different thinking styles – super analytical or super emotional – and after I returned, I had my lab group participate in this type of exercise. And now I feel like I can better assess a persons thinking style and adjust the way I communicate accordingly.
DXS: Did you always have the ability to talk to the general public or does having kids help you to better understand some of the nuances associated with science communication?
LG: I think so. In fact, I am thinking back to when I had a paper in Sciencecome out around the time that I had my first child. It got a lot of news coverage and was featured in Time magazine. I thought it was so cool at the time, but looking back on it I realized that have come a long way. I said something to a journalist, who then asked me to translate it into “plain English.” It was a little bit of a jab.
Now, with kids, I can tell you a lot more about my research and can better see the broader impact. Talking to them helps me to do that. Here is a conversation about my research with my daughter:
L: Mama is working on figuring out how to help the whales that people like to eat. It’s a big problem because some people like to eat whales and some like to see them swimming in the ocean.
G: What we have to do is let the people eat the whales in the ocean, and buy some whales from the pet store to put back in the ocean. How much do whales cost?
L: Good idea. But you can’t buy whales at the store. They are too big. And if we take them all out of the ocean there will be none left.
G: Well instead we should ask the people to eat bad things like sharks.
L: Another good idea. But if we take sharks out there will be no predators to eat the big fish. And the whole ecosystem would collapse.=
G: Well then the people should eat other things like fish instead of whales. They should buy a fishing pole and catch a fish and eat those instead of whales.
L: What about chicken, shouldn’t people just eat chicken?
G: Mama, we can’t kill chickens. Chickens are nicer than fish, so that’s why we have to eat fish.
L: What about just eating vegetables?
G: Oh mama, some people are meat-eaters. And there are no more dinosaurs. They all got extinct. They should have saved some of the dinosaur meat in the freezer for the meat-eaters. When the dinosaurs come back, there will be enough meat to eat and people won’t want to eat whales.
The simplicity of taking myself out of my research bubble and engaging with a creative (and nonlinear?) 7YO has taught me how to be a better communicator – with the media, with my students, and with the general population.
DXS: Do you think these efforts in science communication are helping to shift other peoples perspectives about who a scientist actually is? For instance, are we changing the old crazy haired white guy stereotype?
LG: Well, I hope so. A couple of examples – again, as a mom, one of my daughters a Girl Scout and I get to help with the troop. One of the themes was to teach about environmental and conservations awareness. We did this Crayola molding experiment where we put our fingers into cold water. We then did the same thing except we put modeling clay over our fingers before putting them into the cold water and to learn about adaptations to extreme environments. Also, we play games where they simulate fishing – what if there is plastic? What happens to you if you eat that? My hope is that this shows these young girls that science is both interesting and fun.
Another thing that just happened today is that I was contacted by Martha Stewart’s office, and it seems that some of my research results will be featured in the October issue of Martha Stewart Living. The message here is that I happen to care about the ocean, but I also love sushi. I also I care about health. I am not just a nerd in a lab coat. I am a mom, I do yoga, I have wonderful friends, and here is the kind of science that I do. It seems to me that it is better to connect with others when I can give them something that is relevant to their lives instead of a more abstract ecological theory.
DXS: If you had something you could say to the younger you about getting on your chosen career path, what would you say?
LG: I feel like I have been very effective at figuring out how to get from point A to point B, but less successful at savoring the process. I think that I’d tell myself to make time to celebrate the small victories. I have also learned to identify what kind of research is most exciting, and I would tell myself to say “no” to everything that is only moderately interesting. I tell my grad students that if you don’t dive in head first, you won’t ever know. So why just not give it a try! And if it doesn’t work, move on. Also, if something isn’t making you happy, change! Academia isn’t for everyone, and there is a lot more to life than science.
An historic view interpretation of the placenta (source).
She gave me a few minutes to meet my daughter before she reeled me back into a state that was my new reality. “You’re not finished Jeanne. You still need to birth your placenta.” What?!?! More pushing? But I was lucky and the efforts required to bring my placenta ex vivo were minimal.
This is the second placenta my body helped make. OK, so it doesn’t EXACTLY look like meatloaf…
The idea of a placenta, which is the only human organ to completely and temporarily develop after birth, was fascinating. That thing sitting in a rectangular periwinkle bucket was what allowed me to grow another human.. inside of my body! There was no way I was not going to check it out, as well as create a permanent record of its relatively short-lived existence.
My first impression was that it looked like “meatloaf.” Not necessarily a well made meatloaf, but perhaps one that is made by my mother (sorry mom). But, alas, chaos reigned and I wasn’t able to really take a good look. However, for my second birth and hence second placenta, my midwife indulged me with a more detailed look and a mini-lesson.
Baby’s eye view: Where geekling deux spent 39 weeks and 4 days.
Her gloved hands, still wet with my blood and amniotic fluid, slid into the opening that was artificially created with a tool resembling a crocheting needle. She opened the amniotic sac wide so I could get a baby’s eye view of the crimson organ that served as a nutritional trading post between me and my new bundle of joy.
She explained that the word “placenta” comes from from the Greek word plakoeis, which translates to “flat cake” (however, I’m sure if my mom’s meatloaf was more common in ancient Greece, the placenta would be named differently). “It’s one of the defining features of being a mammal,” she explained as I was working on another mammalian trait – getting my baby to nurse for the first time.
That was about all I could mentally digest at the time, but still, more than three years later, the placenta continues to fascinate me, mostly due to the fact that it is responsible for growing new life. It’s a natural topic for this long overdue Pregnancy101post, so let’s dive in!
Development of the placenta
It all starts when a fertilized egg implants itself into the wall of the uterus. But, in order to fully understand how it works, we should start with an overview of the newly formed embryo.
The very early stages of us (and many other things that are alive).
The trophoblast invades the uterus, leading to implantation of the blastocyst.
As soon as a male sperm cell fuses with a female egg cell, fertilization occurs and the cells begin to multiply. But, they remain contained within a tiny sphere. As the cells continue to divide, they are given precise instructions depending on their location within that sphere, and begin to transform into specific cell types. This process, which is called cellular differentiation, actually seals the fate every cell in our body, sort of like how we all have different jobs – some of us are transport things, some of us are involved in policing the neighborhoods, some of us build structures, some of us communicate information, some of us deal with food, some of us get rid of waste, etc. Every cell gets a job (it’s the only example of 100% employment rates!).
Now back to the cells in the fertilized egg. As they start to learn what their specific job will be, the cells within the sphere will start to organize themselves. After about 5 days after fertilization, the sphere of cells becomes something called a blastocyst, which readies itself for implantationinto the wall of the uterus.
The act of implantation is largely due to the cells found on the perimeter of the blastocyst sphere. These cells, collectively known as the trophoblast, release a very important hormone – human chorionic gonadotropin (hCG) – that tells the uterus to prepare for it’s new tenant. (If you recall, hCG is the hormone picked up by pregnancy tests.) Around day 7, the trophoblast cells start to invade the lining of the uterus, and begin to form the placenta. It is at this point that pregnancy officially begins. (Here is a cool video, created by the UNSW Embryology Department, showing the process of implantation.)
Structure of the placenta
Eventually the trophoblast becomes the recognizable organ that is the placenta. Consider the “flat cake” analogy, with the top of the cake being the fetal side (the side that is in contact with the baby), and the bottom of the cake being the maternal side (the side that is in contact with the mother).
Cross section of the placenta: Blood vessels originating from the fetus sit in a pool of maternal blood, which is constantly replenished my maternal arteries and veins. The red represents oxygenated blood, and the blue represents de-oxygenated blood.
Projecting from the center of the fetal side of the placenta are two arteries and one vein, coiled together in a long, rubbery rope, often bluish-grey in color. This umbilical cord serves as the tunnel through which nutrients and waste are shuttled, and essentially serves to plug the baby into the mother’s metabolic processes. At the umbilical cord-placenta nexus, the umbilical cord arteries and vein branch out into a network of blood vessels, which further divide into a tree-like mass of vessels within the placenta.
These tree-like masses originating from the umbilical cord (and thus fetus) sit in a cavity called the intervillous space, and are bathed in nutrient-rich maternal blood. This maternal blood, which provides the fetus with a means for both nutrient delivery and waste elimination, is continually replenished via a network of maternal arteries and veins that feed into the intervillous space. Furthermore, these arteries and veins help to anchor the placenta into the uterine wall. One of the most interesting aspects about the mother-feus relationship is that the blood vessel connection is indirect. This helps to prevent a detrimental immune response, which could lead to immunological rejection of the fetus (sort of like how a transplanted organ can become rejected by the recipient).
Functions of the placenta
Just like a plant needs sunlight, oxygen, and water to grow, a baby needs all sorts of nutrients to develop. And since a baby also produces waste, by nature of it being alive and all, there is an absolute requirement for waste removal. However, because we can’t just give a developing fetus food or a bottle, nor are we able to change diapers in utero, the onus lies completely on the biological mother.
This is where the placenta comes in. Because the fetus is plugged into the circulatory system of the mother via the umbilical cord and placenta, the fetus is provided with necessary nutrients and a mechanism to get rid of all the byproducts of metabolism. Essentially, the placenta acts as a waitress of sorts – providing the food, and cleaning it all up when the fetus is done eating.
But it’s not just about nutrition and waste. The placenta also serves as a hormone factory, making and secreting biological chemicals to help sustain the pregnancy. I mentioned above that the placenta produces hCG, which pretty much serves as a master regulator for pregnancy in that it helps control the production of maternally produced hormones, estrogen and progesterone. It also helps to suppress the mother’s immunological response to the placenta (along with other factors), which cloaks the growing baby, thereby hiding it from being viewed as a “foreign” invader (like a virus or bacteria).
Another hormone produced by the placenta is human placental lactogen (hPL), which tells the mother to increase her mammary tissue. This helps mom prepare for nursing her baby once it’s born, and is the primary reason why our boobs tend to get bigger when we are pregnant. (Yay for big boobies, but my question is, what the hell transforms our rear ends into giant double cheeseburgers, and what biological purpose does that serve?? But I digress…)
Despite the fact that the mother’s circulatory system remains separate from the baby’s circulatory system, there are a clear mixing of metabolic products (nutrients, waste, hormones, etc). In essence, if it is in mom’s blood stream, it will very likely pass into baby’s blood stream. This is the very reason that pregnant mothers are strongly advised to stay away from cigarettes, drugs, alcohol, and other toxic chemicals, all of which can easily pass through the placental barrier lying between mother and fetus. When moms do not heed this warning, the consequences can be devastating to the developing fetus, potentially leading to birth defects or even miscarriage.
There are also situations that could compromise the functions of the placenta – restriction of blood supply, loss of placental tissue, muted placental growth, just to name a few – reducing the chances of getting and/or staying pregnant. This placental insufficiency is generally accompanied by slow growth of the uterus, low rate of weight gain, and most importantly, reduced fetal growth.
And it’s not just the growth of the placenta that is important – where the placenta attaches to the uterus is also very important. When the placenta grows on top of the opening of the birth canal, the chances for a normal, vaginal birth are obliterated. This condition, known as placenta previa, is actually quite dangerous and can cuase severe bleeding in the third trimester. 0.5% of all women experience this, and it is one of the true medical conditions that absolutely requires a C-section.
Then, there is the issue of attachment. If the placenta doesn’t attach well to the uterus, it could end up peeling away from the uterine wall, which can cause vaginal bleeding, as well as deprive the baby from nutrient delivery and waste disposal. This abruption of the placenta is complicated by the use of drugs, smoking, blood clotting disorders, high blood pressure, or if the mother has diabetes or a history of placental abruption.
Conversely, there are times when the blood vessels originating from the placenta implant too deeply into the uterus, which can lead to a placenta accreta. If this occurs, the mother generally delivers via C-section, followed by a complete hysterectomy.
Cultural norms and the placenta
There are many instances where the placenta plays a huge role in the culture of a society. For instance, both the Maori people of New Zealand and the Navajopeople of Southwestern US will bury the placenta. There is also some folklore associated with the placenta, and several societies believe that it is alive, pehaps serving as a friend for the baby. But the tradition that seems to be making it’s way into the granola culture of the US is one that can be traced back to traditional Chinese practices: eating the placenta.
Placentophagy, or eating one’s own placenta, is very common among a variety of mammalian species. Biologically speaking, it is thought that animals that eat their own placenta do so to hide fresh births from predators, thereby increasing the chances of their babies’ survival. Others have suggested that eating the nutrient-rich placenta helps mothers to recover after giving birth.
However, these days, a growing number of new mothers are opting to ingest that which left their own body (likely) through their own vaginas. And they are doing so though a very expensive process involving dehydrating and encapsulating placental tissue.
Why would one go through this process? The claims are that placentophagy will help ward of post partum depression, increase the supply of milk in a lactating mother, and even slow down the ageing process. But, alas, these are some pretty bold claims that are substantiated only by anecdata, and not actual science (see this).
So, even though my placentas looked like meatloaf, there was no way I was eating them. If you are considering this, I’d approach the issue with great skepticism. There are many a people who will take advantage of maternal vulnerabilities in the name of cold hard cash. And, always remember, if the claims sound to good to be true, they probably are!
Thanks for tuning into this issue of Pregnancy101, and enjoy this hat, and a video!