If you’ve ever been pregnant (or known someone who was), there’s a good chance a bottle of Tylenol — also known as acetaminophen — was sitting in the medicine cabinet. It’s the go-to pain reliever when you’re expecting, recommended by doctors for headaches, fevers, and general “everything hurts” days.

Roughly 70% of pregnant women take it at some point. That’s a lot of Tylenol.

So when a 2021 article suggested that taking acetaminophen during pregnancy might increase the risk of autism or ADHD in kids, the internet freaked out. News outlets ran with scary headlines. Expectant parents panicked.

But a new systematic review and meta-analysis — basically a super study that pulls together all the best available research — just dropped, and it’s here to clear the air.

The Big Question: Does Tylenol Really Affect a Baby’s Brain?

Short answer: There might be a small link — but it’s complicated, and not nearly as scary as headlines made it sound.

The researchers looked at dozens of studies on acetaminophen use during pregnancy and found that:

  • There was a 17% higher risk of ADHD in children whose moms took acetaminophen while pregnant.
  • The risk for autism or other developmental disorders? No strong evidence.

But here’s where it gets interesting: when the data was analyzed using stricter, more precise methods — accounting for things like genetics, family environment, and how “exposure” was measured — that supposed link to ADHD became less convincing.

In studies that compared siblings (one exposed to Tylenol in the womb, one not), the difference basically disappeared.

Translation: the association might not be Tylenol’s fault at all. It could be confounding factors — like genetics, the mother’s health, stress, or why she took Tylenol in the first place.

Why This Research Is So Tricky

Studying something like this isn’t easy. Tylenol is over-the-counter, meaning no one tracks how much or how often people actually take it. Most studies rely on self-reports (“How many pills did you take during your second trimester?”), which isn’t exactly precise.

Then there’s the problem of confounding by indication — a fancy way of saying “what if it’s not the drug, but the reason for taking it?”
For example, untreated fever during pregnancy has been linked to developmental problems too. So if a mom takes Tylenol for a fever, and her child later develops ADHD, is it the fever, the medication, or something else entirely?

Even diagnosing ADHD or autism in studies isn’t straightforward. Many rely on parent questionnaires or insurance data, which can be inaccurate or inconsistent.

What This New Study Did Differently

This wasn’t your average review. The research team:

  • Followed strict protocols (PRISMA, GRADE, Cochrane — the gold standards of scientific reviews).
  • Screened for quality, excluding weak or biased studies.
  • Used quantitative bias analysis, a fancy math trick to test how much study errors might skew results.

Their conclusion?
👉 There’s a possible small association between acetaminophen use in pregnancy and ADHD, but it could easily be explained by bias or other unmeasured factors.
👉 There’s no solid evidence of a link to autism or other neurodevelopmental disorders.

So What Should Pregnant Women Do?

Don’t panic — and don’t toss your Tylenol.

Experts still say acetaminophen is the safest pain and fever option during pregnancy when used correctly. The CDC and the American College of Obstetricians and Gynecologists both back that up.

The key is moderation:

  • Use the lowest effective dose.
  • For the shortest necessary time.
  • Check with your doctor first.

Untreated pain or fever can be dangerous too — so it’s about balance, not fear.

Bottom Line

This new meta-analysis adds some clarity to the debate:

  • There’s some signal that heavy Tylenol use during pregnancy might be linked to ADHD.
  • But the science isn’t solid enough to prove it’s cause-and-effect.
  • And when studies use better methods, that signal fades fast.

In other words, the “Tylenol causes ADHD” story?
Still more smoke than fire.

Bérard A, Cottin J, Leal LF, Picot C, Pleau J, Friedman JM, Damkier P, Cucherat M, Alwan S, Jurek L, Winn LM, Carleton BC, Bertoldi AD, Grandi SM, Masarwa R, Dodin P, Ceulemans M, Platt RW, Nourredine M, Gram EB, Veroniki AA, Massardier J, Tricco AC. Systematic Review and Meta-Analysis: Acetaminophen Use During Pregnancy and the Risk of Neurodevelopmental Disorders in Childhood. J Am Acad Child Adolesc Psychiatry. 2025 Sep 30:S0890-8567(25)02106-9. doi: 10.1016/j.jaac.2025.09.031. Epub ahead of print. PMID: 41062061.