Painkillers and Pregnancy

Which medications can you safely take?

Pregnancy can sometimes be a nonstop ride through Pain-ville. Whether it’s back pain, aching hips, swelling ankles, headaches, burning stretching sensations, or any number of other problems, sometimes you just want some relief. Tara’s first son would have given David Beckham a run for his money in the womb – he once repeatedly kicked her right rib for more than an hour (before she knew to get on all fours and try to shift his position), and the resulting soreness lasted until the end of the pregnancy.

But pain during pregnancy presents a dilemma: what can you take to drug yourself without drugging the fetus – or at least without causing any kind of long-term problems for your baby later on? It would be nice if we had a reliable, effective selection of pain relievers that were guaranteed to be safe for us and our fetus, whether we needed them for pain or more serious concerns, such as fevers, strep throat, or surgical pain. If we did, such medications would fall under Category A in the FDA’s classification system for medications’ safety profiles during pregnancy.

Alas, we don’t. Most of the pain medications we would be likely to pull out of our medicine cabinets, or seek a prescription for, fall under Category B (generally safe because we don’t have evidence of risk so far) or Category C (animal studies show a risk and/or we just don’t have good data for humans). So that leaves us having to sift through the evidence we do have to decide: can I pop this pill without harming that little creature I’m incubating?

We’ve got three main groups of drugs to examine in answering this question: opioids, or narcotics, that typically require a prescription; non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and aspirin; and good old acetaminophen (Tylenol or paracetamol).

Opioids and Narcotics

Opioids, which relieve pain by working in the central brain, include hydrocodone, codeine, oxycodone, morphine, tramadol and methadone, among others. They are commonly prescribed during pregnancy, taken by as many as one in five women, and most, particularly hydrocodone, codeine, and oxycodone, have been regarded as safe enough if a woman needs them even though they cross the placenta. Despite all the women who have taken them, however, the available data on them, outside of a couple special circumstances, is not actually that great.

The majority of research on opioids in pregnancy focuses on labor pain use, which has been linked to a small increased risk of respiratory distress in the newborn, or on addiction, which doesn’t offer much guidance for medically indicated use. For use throughout pregnancy when prescribed for pain, surgery or infections, the research is sparse: we’ve drugged up a lot of rats and pigs and other poor lab creatures to learn what happens to their babies, but in humans, we only have small case-control studies with inconsistent results. Experts have historically thought these meds don’t pose much risk to the fetus, but a lack of data shouldn’t mean presumed safety, and two recent, large studies have cast some doubt on that those assumptions.

One involved more than 20,000 women and found that using an opioid at any point during pregnancy was linked to a slightly increased risk of neural tube defects, about 6 defects among every 10,000 women’s children. The other similarly large study linked opioids taken during the first trimester to a couple of heart defects, gastroschisis (intestines outside the body) and spina bifida, which is a neural tube defect. Codeine and/or hydrocodone were the biggest offenders, but then they were also the drugs most commonly taken, which means the data set was bigger. Oxycodone, another common one, was linked to only one heart defect.

On the surface, these studies should seem pretty reliable because they involved so many women, but they covered such a wide range of birth defects that each subgroup had much smaller numbers of kids. Some groupings were so small there was no way to know if the results were more than chance. Plus, dosages weren’t taken into account, and the data was based on mothers’ recalling what they took up to two years after their pregnancies – it’s doubtful they all had the apocryphal memory of an elephant.

So where does that leave us? If you need to take these medications, you can feel confident that no major red flags have been spotted in the many decades they’ve already been used in pregnant women. If a serious and common risk resulted from opioid use, we’d know by now. But that doesn’t mean they’re harmless and pose no risk. It just appears to be small enough that the benefits likely outweigh the risk, when the drug is really needed. Really, though, we need better data.

Over-the-Counter Meds

Although a little over a dozen NSAIDs are prescription-only, the most common are the three OTC ones: aspirin, ibuprofen and naproxen. We know a lot more about these drugs in pregnancy – especially that they’re not safe during the third trimester – but there are still conflicting data about early pregnancy use. Some large studies have found links to miscarriage or birth defectsothers found no such risks, and a meta-analysis found – you guessed it – mixed results.

The play-it-safe route, then, is to avoid NSAIDs at any point while pregnant, but definitely steer clear of them in the third trimester, when they can wreak all kinds of havoc: delaying labor, increasing blood loss during birth and increasing anemia in the mother, and, in the fetus, causing high blood pressure or kidney problems and prematurely closing a blood vessel that diverts blood away from the underdeveloped lungs until birth.

That brings us to tried-and-true Tylenol, where we (finally!) get some good news. The evidence showing that acetaminophen doesn’t cause birth defects is pretty solid (one recent study had more than 88,000 women). In fact, the birth defects that tend to freak most women out when they worry about this stuff – head, neural tube, intestinal, ear and cleft palate defects – were all less common among women popping acetaminophen for fevers or infections compared to those who suffered through such maladies. That tells us how important it is to treat serious illness in pregnancy.

But when they look hard enough, researchers will find a way to throw pregnant women into a tizzy all over again, wondering if they can take a couple Tylenol for their pounding headache without bestowing some lifelong hardship on their kid. One of these big scares links acetaminophen in pregnancy to the child’s later development of asthma. But the studies finding this link didn’t account for all the reasons women might have taken the acetaminophen in the first place. Whether it was fevers, migraines, infections, chronic illnesses or something else, it’s possible some of those conditions could have been the culprit in causing later asthma – if the asthma can even be traced back to something in pregnancy, which isn’t a sure bet either.

When other studies did account for those factors, or, gee, considered the fact that mom’s asthma might play a role here, then poof! The link pretty much vanishes. Heck, one study of about 1,500 women found less asthma among the 6-year-old children of moms who took acetaminophen in the first or third trimesters. Even women popping Tylenol pretty regularly – up to 10,400 mg (32 regular strength tablets) a month – didn’t have more asthmatic kids than other moms.

Then there was that big study grabbing headlines in 2013 that linked prenatal acetaminophen with the specter of ADHD. But it was just one study that had a lot of weaknesses: the authors did not use official diagnoses of ADHD (only parent report of ADHD behaviors), only certain medical conditions (such as fever) were included as confounders, dosages were not calculated, and about a third of the women had missing data. In short, you can forget that study existed until a LOT more other studies come along and find the same thing.

The bottom line? We don’t currently have any convincing evidence that acetaminophen used as directed during pregnancy is something to worry about. In fact, using it to treat a serious condition might reduce your child’s risk of a birth defect. One study found neural tube defects were twice as likely in women who had a fever-related illness during pregnancy. Acetaminophen is a fever reducer, so withholding it might endanger the fetus.

The only time we need to worry about acetaminophen based on what we know so far is with overdoses. It’s the most common drug implicated in overdoses during pregnancy, and an overdose is serious, causing liver damage and possibly death. The best way to avoid an overdose is to take it as directed and to check the labels of other combination meds, such as cold medicines, that often include it as an ingredient.

So next time you stumble into the bathroom and stare blankly into your medicine cabinet with a steam train barreling between your temples, at least you have a clearer sense of what your options are.

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