Tylenol, Autism, and Pregnancy: What the Science Really Says (and Why Listening to Your Doctor Matters)
đź‘‹ Professional Note
I’m a Registered Dietitian (RD/CSR). While I don’t prescribe medications, part of my role is to translate complex health science into plain language so you can make informed decisions. This article is for education only — always talk to your OB/GYN, pharmacist, or healthcare provider before starting or stopping any medication.
🔑 Quick Take
The best available science shows no causal link between acetaminophen (Tylenol) use in pregnancy and autism.
Untreated fever and pain can harm both mom and baby — this is not the time to prove you can “tough it out.” Treating fever promptly — often with acetaminophen — remains the safest recommendation from ACOG and SMFM.
Why This Debate Is Everywhere
You may have seen viral posts or political soundbites blaming Tylenol for autism. This understandably sparks fear — especially for expecting parents. But experts warn these claims are not supported by strong evidence and can actually put pregnancies at risk by discouraging treatment of fever and pain. Yet here we are again listening to the most unqualified people giving their two cents while ignoring the medical community and the research. How did we get here… well I think the majority of people understand how we got here…moving on.
The Real Risk: Untreated Fever
Before we even talk about Tylenol, we need to consider what happens when fever goes untreated:
First trimester: Higher risk of neural tube defects, heart defects, cleft lip/palate
Any trimester: Increased risk of miscarriage, preterm labor, low birth weight, dehydration, worsening infection
For mom: Fevers stress the heart, raise metabolic demand, and can be exhausting
In short — doing nothing is not the safer choice.
What the Strongest Research Shows
The Largest Study to Date: JAMA Psychiatry 2024 study
Who & What They Studied:
Researchers followed 2.48 million kids in Sweden whose moms used (or didn’t use) Tylenol during pregnancy. They tracked them for autism, ADHD, and intellectual disability using medical records.
How They Studied It:
They did two kinds of comparisons:
General population analysis: Compared kids whose moms took Tylenol vs. didn’t, adjusting for things like mom’s health, smoking, income, age, etc.
Sibling analysis: Compared brothers/sisters from the same mom — one pregnancy with Tylenol, one without — which helps account for genetics and family environment.
What They Found:
In the big population analysis, there was a tiny bump in autism/ADHD risk — but very small (about 0.1–0.2% higher).
In the sibling analysis (the more powerful method), the risk completely disappeared.
They also looked at higher vs. lower doses and found no clear pattern showing “more Tylenol = more risk.”
What It Means:
The small risks seen in earlier studies are probably explained by other factors — like the reason moms were taking Tylenol in the first place (fever, infection, pain) — not by Tylenol itself.
This study is one of the biggest and best-designed to date and supports what doctors have been saying:
Tylenol, when used appropriately, is still considered the safest option for pain and fever in pregnancy.
ACOG’s 2025 Statement
“In more than two decades of research… not a single reputable study has successfully concluded that the use of acetaminophen in any trimester of pregnancy causes neurodevelopmental disorders.”
Bottom line: There is research to show an association between acetaminophen and neurological disorders such as autism. However, when studies control for confounders, the supposed link disappears, meaning the data shows no causation. So listen to your doctors on what the safe amount to take is, based on decades of research. We already know that NSAIDS like ibuprofen has known risks which is why they are on the not safe to take for pregnancy
🧠Callout: What Are Confounders?
A confounder is a hidden factor that influences both the thing being studied (Tylenol use) and the outcome (autism risk), making it look like there’s a connection — even if there isn’t.
Example: Pregnant people with infections are:
More likely to take Tylenol (to manage fever or pain)
Slightly more likely to have babies with neurodevelopmental challenges (because infection itself can affect pregnancy)
If researchers don’t fully account for the infection, it may look like Tylenol caused the outcome — when the infection was the real driver.
Common Confounders:
Maternal illness (fever, viral infections, chronic inflammation)
Genetics (family history of autism, ADHD)
Socioeconomic factors (access to care, education, stress)
Environmental exposures (smoking, pollutants)
When high-quality studies control for these confounders, the Tylenol-autism association mostly disappears.
RFK Jr., Lawsuits, and the “Research” They Cite
RFK Jr. and some politicians have amplified the Tylenol-autism claim, often citing Baccarelli’s work. Here’s the context:
To break it down, its not a new study with participants and interventions that they looked at. Instead, they reviewed 46 prior studies that investigated prenatal acetaminophen use and neurological disorders.
The paper is titled “Evaluation of the evidence on acetaminophen use and neurodevelopmental disorders using the Navigation Guide methodology”
The Navigation Guide is a method used to evaluate environmental health evidence
The Conclusion: they found an association consistent with increased incidence of neurodevelopmental disorders in children whose mothers had taken acetaminophen during pregnancy. HOWEVER, they also emphasized that observational data cannot prove causation.
Think of it like this:
People who eat more ice cream also get more sunburns — not because ice cream causes sunburn, but because it’s summer. Tylenol use may simply be a marker for other factors (like infection) rather than the cause of autism.
🥕 Another Example: Beta-Carotene & Lung Cancer
I want to give you another real-world example of why correlation doesn’t always equal causation — and why it matters for the Tylenol debate.
I teach Health 422 at the University of South Dakota, and early in the semester we spend time on how to read and interpret research. One study I use every year looks at beta-carotene supplementation in smokers. (I was reminded of it recently by a social clip from Jessica Knurick — an amazing dietitian to follow if you don’t already.)
Here’s what happened:
Step 1: The observation. Early studies showed that people with higher blood levels of beta-carotene had lower rates of lung cancer. The easy conclusion?
“More beta-carotene must protect against cancer!”
Step 2: The hypothesis. Researchers thought they’d found a cancer-prevention breakthrough: give smokers beta-carotene supplements and prevent thousands of lung cancers.
Step 3: The randomized trial (CARET). When they finally did the gold-standard study — the Carotene and Retinol Efficacy Trial (CARET) — they were shocked.
The group taking beta-carotene + vitamin A actually had higher rates of lung cancer and higher mortality than the placebo group.
The trial was stopped early for safety.
The likely explanation? The first observational studies were seeing the healthy lifestyle effect: people with higher beta-carotene levels were also the ones who exercised more, ate more vegetables, and smoked less — all of which lower cancer risk. When researchers isolated beta-carotene and gave it as a high-dose supplement, it didn’t replicate those benefits and made things worse for smokers.
đź”— The Connection to Tylenol
This is the same kind of issue we see with Tylenol and autism:
Observational studies can spot patterns (Tylenol use → higher autism risk), but those patterns are tangled up with confounders — the reasons people took Tylenol in the first place (fever, infection, pain).
When better studies control for genetics, family environment, and maternal illness — like the massive JAMA sibling-comparison study — the supposed risk basically disappears.
Just like with beta-carotene, the early correlation didn’t hold up when we looked more carefully.
My Takeaways from the Research
Evidence Is Limited & Inconsistent: Most studies don’t show a strong or consistent link, especially once you adjust for genetics, maternal illness, and socioeconomic factors.
No Clear Dose-Response: If Tylenol were causal, higher use should = higher risk — but this pattern doesn’t consistently appear.
Confounding Is a Big Issue: Maternal illness (the reason for taking Tylenol) might explain many of the observed associations, not the medication itself.
Overall Evidence Grade: Using the Navigation Guide approach, the data is considered “inadequate or limited” to prove a causal link.
My bottom line: The risk of leaving a fever untreated is far more proven and dangerous than the hypothetical risk of taking Tylenol.
Practical Guidance for Expecting Parents
Pregnancy already limits medication choices — which makes this conversation so critical.
✅ Talk to your OB/GYN or pharmacist — they know your history and can weigh benefits vs. risks.
✅ Don’t ignore fevers or severe pain — research shows doing so carries risks for both mom and baby.
✅ Rely on evidence-based recommendations — medical societies continue to list acetaminophen as the safest option when needed.
Why This Debate Feels a bit Sexist… in my opinion
Pregnancy already comes with plenty of unsolicited advice (“Sleep now while you can!”). Taking away one of the few safe, evidence-backed meds left in the toolkit is not just unhelpful — it’s dismissive of pregnant people’s needs.
Calls to restrict acetaminophen effectively say: “Endure pain, risk untreated fever, or turn to riskier alternatives — because of a claim that isn’t supported by science.”That’’s not just bad medicine — it’s a reproductive equity issue. Pregnancy deserve evidence-based care, not political soundbites.
Where Dietitians & AND Fit In
The Academy of Nutrition and Dietetics (AND) doesn’t have a formal statement on acetaminophen and autism — and that’s appropriate, since medications are outside our direct scope. But RDs are trained to interpret science and collaborate with physicians and pharmacists.
If AND ever issued guidance, it would almost certainly echo ACOG/SMFM and the entire medical community: Acetaminophen remains the safest recommended option for fever and pain in pregnancy when clinically indicated.
Final Word
I get it—headlines like these can be pretty intimidating, especially when they highlight an “association” without the full context. That’s why it’s so important to let science do its thing and trust the health professionals who dedicate their careers to understanding this stuff. Research isn’t a one-and-done deal. It takes multiple studies, repeated results, and a lot of patience. Think of it as a scientific relay race—you gotta pass the baton multiple times before you get the full picture. Sure, it can be exhausting, but that’s how we build reliable knowledge.
And here’s a little perspective on research that’s tricky to study, like the Tylenol debate. Why is it so hard? Well, ethically, we can’t just give thousands of pregnant women different doses of Tylenol and see who develops autism—that would be wildly irresponsible and unethical. Instead, we rely on observational studies and statistical models to piece together the puzzle. It’s a slow process, but it’s the best we can do without crossing ethical lines.
Overall, you all deserve better than fear-mongering. The best and most reliable research—and every major medical society—supports the careful, short-term use of acetaminophen during pregnancy when necessary.
Pregnancy is tough enough without unnecessary fear. Trust the evidence, treat fevers when they happen, and have honest conversations with your healthcare team. Because good science, like good humor, should always be part of the conversation.
