What You Really Need to Know About Tylenol and Pregnancy
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At a press conference completely out of touch with reality as understood by scientists and doctors, President Trump announced yesterday that the Food and Drug Administration (FDA) will warn doctors and patients against the use of acetaminophen (such as Tylenol) during pregnancy. There have been other unsubstantiated claims about vaccines and autism, so let me clarify what is actually known and understood.
What is acetaminophen?
Acetaminophen is an over-the-counter medication used to relieve pain and reduce fever. Tylenol’s flagship products are acetaminophen tablets and syrups, but Tylenol also sells other products, including those with a mixture of active ingredients. (Always check the medication label when taking medications to ensure you know what you’re getting.) I’ll often use the word “Tylenol” because it’s more well-known, but acetaminophen is also found in other medications, such as Excedrin and NyQuil.
Outside the US, acetaminophen is often referred to as paracetamol—the same drug, but a different generic name—though Trump appeared to stick with the brand name Tylenol during his press conference. The Tylenol company’s website now features a pop-up directing customers to this answer , which correctly points out that there is no credible link between Tylenol and autism.
What the Science Really Says About Acetaminophen and Autism
The short answer: There is no definitive link between autism and acetaminophen use during pregnancy. However, U.S. Secretary of Health and Human Services Robert F. Kennedy Jr. was largely correct when he stated at a press conference that some studies “suggest a potential” link between acetaminophen and autism. For example, a review published this year (not the study itself, but an analysis of previous studies) found that some studies do show a link between acetaminophen use during pregnancy and autism, although the evidence is mixed.
The press release announcing the review noted, “While the study does not prove that acetaminophen directly causes neurodevelopmental impairments [emphasis added], the research team’s findings strengthen the evidence for a link and raise concerns about current clinical practice.” However, it appears most medical experts are not convinced that this review or the studies claiming a link are compelling enough to change clinical practice. (More on what medical experts have to say about these claims in the next section.)
So why isn’t this considered compelling evidence? Association (two events typically occurring together) is not the same as causation (one event clearly causes the other). People who take acetaminophen during pregnancy tend to differ from those who don’t. For example, if a woman takes Tylenol during pregnancy due to an illness, the illness itself, not the Tylenol itself, may be the risk factor. Or people who take Tylenol may differ from those who don’t in some other way.
A large study published last year took this into account. Researchers examined 2.5 million children in Sweden, and their initial analysis found an increased risk of autism in children whose mothers took acetaminophen. But then they tested whether this association persisted among siblings, one of whom was exposed to acetaminophen in the womb and the other was not. And the association disappeared.
In other words, if acetaminophen increased the risk of autism, one would expect that a sibling exposed to the drug in utero would be more likely to develop autism than a sibling not exposed to the drug. But this hasn’t happened. Instead, it appears that some families are more likely to have children with autism than others, and acetaminophen use does not increase the risk in these families.
What medical experts say about using acetaminophen during pregnancy
Acetaminophen (including Tylenol) is generally considered the safest pain reliever for pregnant women. Other common alternatives, such as ibuprofen, have known risks and are not recommended if you can take acetaminophen. Medical experts also agree that leaving pain and fever untreated during pregnancy is dangerous.
Several medical organizations released statements in response to the president’s press conference. Each statement is worth reading in full, but here are some key quotes from each:
The American College of Obstetricians and Gynecologists stated in a statement : “Suggestions that acetaminophen use during pregnancy causes autism are not only deeply concerning to physicians but also irresponsible, given the harmful and confusing message they send to pregnant patients, including those who may require this helpful medication during pregnancy.” The statement goes on to discuss the strength of the evidence: “No reputable studies have concluded that acetaminophen use during any trimester of pregnancy causes neurodevelopmental disabilities in children.”
The Society for Maternal-Fetal Medicine (SMFM) stated in a statement : “In response to today’s announcement at the White House press conference, the Society for Maternal-Fetal Medicine (SMFM) reiterates its recommendation to inform both physicians and patients that acetaminophen is an appropriate medication for the treatment of pain and fever during pregnancy. Despite claims to the contrary, a thorough review of existing studies suggesting a potential association between acetaminophen use during pregnancy and an increased risk of autism and attention deficit hyperactivity disorder (ADHD) in children has not found a causal relationship.”
The American Academy of Pediatrics said in a statement : “Today’s White House event on autism was filled with dangerous claims and misleading information that sends a confusing message to parents and expectant parents and does a disservice to people with autism. … Families with questions about their child’s medications, child care plans for children with autism, or other medical care should consult with their pediatrician or healthcare provider.”
The Autism Science Foundation said in a statement : “Any link between acetaminophen and autism is based on limited, conflicting, and inconsistent scientific evidence and is premature… Today’s announcement distracts from the urgent scientific work needed to understand the true causes of autism and develop more effective supports and interventions for people with autism and their families.”
The European Medicines Agency , which plays a similar role in Europe to the FDA in the US, issued a statement declaring that there is no new evidence to warrant a reassessment of the status or labeling of acetaminophen, which they refer to as paracetamol. “Paracetamol remains an important treatment for pain and fever in pregnant women. Our recommendations are based on a thorough assessment of the available scientific evidence, and we have found no evidence that paracetamol use during pregnancy causes autism in children.”
There is no evidence that vaccines cause autism.
The press conference also repeated long-debunked myths about vaccines and autism. There is no credible connection with vaccines in general, specific vaccine components such as mercury, or combination vaccines such as MMR (measles-mumps-rubella).
And I shouldn’t be telling any parent this, but babies aren’t actually “pumped” with a “tank” of “80 different vaccines” in “one visit,” as Trump claimed. During their first year of life, babies visit the pediatrician every few months, receiving several vaccinations at a time, many of which are combination shots (not just MMR). Many of these vaccines require multiple doses—not a single shot of each.
Therefore, the claim that splitting the MMR vaccine into its components “has no downsides” is false. Splitting the vaccines means children are given more needle sticks and delaying the final dose of each vaccine to ensure full protection. (The Centers for Disease Control and Prevention’s (CDC) Vaccine Advisory Board, stripped of its experienced experts and filled with controversial replacement candidates hand-picked by the Secretary of Health and Human Services, himself a longtime anti-vaccine activist, has already voted to remove the combined MMR-varicella vaccine from the routine vaccination schedule for young children.)
Trump also repeated the myth that babies don’t need hepatitis B vaccinations at birth . Hepatitis B can be transmitted sexually, of course, but not only that . Babies can become infected at birth from an unknowing parent; they can also become infected during childhood from various non-sexual and non-medicinal exposures. Hepatitis B is a more severe disease the earlier you get it, and this is one of the vaccines that infants’ immune systems can process even at such an early age (not all vaccines work that early), so the risk-benefit calculation is simple: this vaccine, like others, provides real protection to children.