Nick Norwitz MD PhD addresses whether prenatal Tylenol use causes autism. A large JAMA study of 2.5 million children found a 0.09% increased risk, but a sibling analysis eliminated the effect, suggesting confounding rather than causation. He urges caution interpreting the findings.
If you're a mother who took Tylenol during pregnancy and now you're feeling guilty like you did something to your kid's neurodevelopment, hear me out for just one minute. First, let me introduce myself. My name is Dr. Nick Norwitz. I'm an MD-PhD, but letters aside, I'm not pretending to be the expert on autism and Tylenol. That said, I can read the literature and try to communicate it to you. So let me give you an example. A study was published in JAMA last year that looked at 2.5 million children. They followed them until age 10 and found a very small association between Tylenol use and autism, specifically a 0.09% increase increased risk of autism. However, this was a correlation. It doesn't prove causation and it's subject to confounding. So the researchers then did something interesting. They did a matched sibling pair analysis, looking at full siblings because they share half their DNA. This can help work out genetic confounding. When they did that, the effect completely disappeared. In fact, if anything, it trended in the opposite direction. So this isn't to say that one study is the be-all end-all. This is to say we need to approach the science with more humility More compassion, less finger-pointing and teasing. And if you want more information, just comment yes and I'll send you a direct message with a letter on this topic. Then we can evolve the conversation. Stay curious.
