Jan 11, 2018

Interview Transcript

Dr. Jones: We get so much advice when we're pregnant, "Do this. Don't do that. This is safe. This could harm your baby." We get this from our mothers, our aunties, our doctors, and the web. Now, there's rumble about acetaminophen, pregnancy and the risk of ADHD. What to do? This is Dr. Kirtly Jones from Obstetrics and Gynecology from the University of Utah Health, and this is The Scope.

Announcer: Covering all aspects of women's health, this is The Seven Domains of Women's Health with Dr. Kirtly Hones on The Scope.

Dr. Jones: In my mother's day, women were told that smoking was good in pregnancy because it made smaller babies with, hopefully, easier births. Well, smoking does do that, but the babies are smaller not in a good way. When we're told that alcohol wouldn't hurt them or the baby, and it would relax the mom, and it would help with breastfeeding. Well, we don't say that anymore. So what is the story?

Let's start with the back story. Women used to take aspirin when they were pregnant with pain or fever, and we thought it was safe for the fetus. Well, we know that it's pretty safe from some very large studies done in the '60s and '70s. But with the rise of acetaminophen, that's known as Tylenol, that was thought to be safer. We're very worried about excess use of narcotics in pregnancy with the risk of addiction in the mom and neonatal abstinence syndrome with the baby, withdrawal symptoms in the newborn. We also worry about softer science of neurologic problems in the developing brain with narcotics that may increase the risk of addiction and learning problems later in life. So we have told women who have fever or pain to take acetaminophen. One brand is Tylenol.

Now, computers have allowed us to look at very big data in health outcomes. And National Health Programs in Scandinavia can track pregnancies and outcomes in millions of women. These studies have informed us about a lot of practices that are good, or not so good for your health.

In the past several years, there have been several very large studies that have suggested that the relatively long-term use of acetaminophen in pregnancy can increase the risk of ADHD, Attention Deficit and Hyperactivity Disorder. These most recent studies, and the most recent one from Norway, followed over 100,000 pregnancies and looked specifically at the use of acetaminophen in pregnancy and the outcome of ADHD in a child.

Now, this is not a randomized controlled study. So many women were given acetaminophen when they had a fever and so many women were given aspirin, and so many women were given placebo. And as we know, that fevers themselves can increase the risk of adverse neurologic outcomes in babies. The study we should do is take women who are pregnant and randomize them to acetaminophen or placebo, and just give it to them not for fever or pain, just for research. One group just for the few days, one group for a month, and then see what happens to the babies. Well, that would be such a great idea, but that study isn't going to happen.

So we can do that with rats, but it's hard to know if rat brains are a good model for baby brains, and it's sort of hard to know if a rat has attention deficit disorder. So we are left with association studies. And that is what this one is about. Women who took acetaminophen for more than a month, 29 days to be exact, when they were pregnant, had two times the incidence of ADHD in their children.

Now, this study didn't come out of the blue. It was done because two earlier studies on smaller numbers of pregnancies found there was an association of long-term use of acetaminophen in pregnancy with neurologic development in the children. This recent study was large enough that they could control for smoking, depression, and other symptoms as long as the women reported these symptoms in pregnancy. They could also control for whether the mother or the father has ADHD because there's some suggestion that it might be inherited.

There are some interesting outcomes. If women took acetaminophen for just a few days during pregnancy, their babies had a decreased risk of ADHD. That's weird. A really interesting finding for me was the association of ADHD in babies whose fathers took acetaminophen. Men who supposedly were the fathers of the pregnancy who had taken acetaminophen for 29 days or more before the conception fathered twice as many children with ADHD. Go figure. The authors write, "The association between paternal preconception acetaminophen use and ADHD was similar to the association between maternal use of acetaminophen during pregnancy and ADHD." Now, here we're dealing with some difficulties and biological plausibility. How does a guy who takes acetaminophen before he makes a baby increase the baby's chance of ADHD?

There's still a lot of room for the fact that women who take acetaminophen for more than 29 days during pregnancy could be a different group of women than pregnant moms who don't. They may have other behavioral and neurologic patterns that cannot be controlled for. Are they more anxious? Do they have a lower pain threshold? Maybe the women who took a lot of acetaminophen are more impulsive. They just go for the bottle of medicine when they don't feel well. All of these conditions can increase stress in the mother in pregnancy and that has been associated with learning problems in children. Stress alone can increase learning problems in children.

Now, there are some animal models that suggest that long term in a mouse world can affect neurologic development if you use a lot acetaminophen in a mouse pregnancy. But, again, we don't know if mice are a good model and what is the appropriate mouse dose and duration to study. So what's the problem?

Well, about 70% of women in the U.S. take acetaminophen during pregnancy, mostly short term for a fever with a cold, with a flu, or maybe a headache but maybe just for two to five days total. Women who take it for a long time may have chronic inflammation disorders like arthritis. Again, chronic inflammation pain had their own effect on the development fetal brain other than the acetaminophen women might take with them. So what are you supposed to do? You're not supposed to take aspirin. You're not supposed to take hot baths. You're not supposed to take narcotics. So if you have taken acetaminophen for a few times for fever, don't worry. Reasonable short-term use is not associated with ADHD. In fact, the risk was slightly lower.

If you have chronic headaches or other problems that you feel you need daily pain management for, perhaps you can talk to your clinician about options. This isn't easy to be perfectly moderate in everything you do when you're pregnant. It's hard to be perfect. And what about those dads? They should clean up their act, too.

But I think we've got some answers. We have some alternatives. We shouldn't be too worried about this, and thanks for joining us on The Scope.

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