During this week’s White House press conference in which President Trump named the over-the-counter drug Tylenol as a possible cause of rising autism rates, he did not mince words, urging pregnant women to “fight like hell” not to take it.

But outside those remarks in the Roosevelt Room — during which Trump himself acknowledged “I’m not so careful with what I say” — the discussion on the common fever and pain reliever’s role during pregnancy is a lot more nuanced.

What the research on Tylenol use during pregnancy actually says

Physicians, researchers on the very studies cited in support of Trump’s position and even other members of the president’s administration are largely united on a few key facts: untreated fevers in pregnancy pose real risks to the fetus, acetaminophen (Tylenol’s active ingredient) remains the safest medication to treat them and any pregnant person seeking advice on the issue should consult their doctor.

“All that we should be asking of the medical profession [is] to actually weigh the risks and benefits for the women, with the women, and be cautious about chronic use of pain medications,” said Dr. Beate Ritz, a UCLA professor of epidemiology who co-authored a paper published last month that the White House cited as evidence for the link between Tylenol and autism.

Ritz said it has been misinterpreted.

The conclusion of the paper, which reviewed existing studies on the topic, was that the association between acetaminophen use in pregnancy and later diagnoses of neurodevelopmental disorders in kids was strong enough to merit doctors’ consideration when determining how to treat fever or pain in pregnancy. The group did not determine a causal relationship between the drug and autism, or suggest barring the drug altogether, she said.

“Looking at all of these studies, yes, there is a risk,” Ritz said. “It’s not very big, but it’s there, but the risk increases are more seen in regular users of Tylenol. This is not a woman who has a fever and takes three Tylenols.”

“There is always a weighing of the risks and the benefits, and fever in women is no good either. … Not having to take any pain medications when you are in severe pain or in chronic pain is also very cruel,” she said. “We all should have an interest in helping out here, making the right decisions without blaming the victim and putting it all on the individual woman.”

Her co-author, University of Massachusetts epidemiologist Ann Bauer, has made similar statements.

“What we recommend is judicious use — the lowest effective dose [for] the shortest duration of time under medical guidance and supervision, tailored to the individual,” Bauer told the news outlet Politico.

The administration’s confusing recommendations

Ultimately, that’s what the administration is recommending as well.

The letter that U.S. Food and Drug Administrator Dr. Marty Makary sent to physicians this week made clear that “a causal relationship” between autism and acetaminophen “has not been established and there are contrary studies in the scientific literature.”

It went on to recommend that clinicians consider limiting their use of acetaminophen for routine low-grade fevers during pregnancy, while noting that medical advice “should also be balanced with the fact that acetaminophen is the safest over-the-counter alternative in pregnancy among all analgesics and antipyretics.” (An analgesic is a pain reliever; an antipyretic reduces fever.)

Untreated fevers during pregnancy are associated with higher rates of birth defects, particularly those of the heart, brain and spinal cord; premature birth; low birth weight; neurodevelopmental disorders including autism; and fetal death, said Dr. E. Nicole Teal, an assistant professor of maternal-fetal medicine at UC San Diego.

“The FDA’s letter, while significantly more nuanced than the president’s comments on the issue, still gives too much weight to findings from poorly designed studies,” she said.

She said she will continue to prescribe acetaminophen to pregnant patients who need to treat fevers or severe pain, as it has the fewest known risks in pregnancy.

Are there other pain-relief and fever-reducing drugs that can be used during pregnancy?

Nonsteroidal anti-inflammatory drugs like ibuprofen (often sold as Advil) or naproxen (often sold as Aleve) are linked to problems with blood vessel and kidney development, as well as oligohydramnios, a condition in which there isn’t enough amniotic fluid to support a healthy pregnancy. Aspirin raises the risk of bleeding complications, and narcotics — which can relieve pain but not fever — pose addiction risks for the mother and infant alike, Teal said.

She referred to a statement from the American College of Obstetricians and Gynecologists noting that two decades of research on the question had failed to find a causal relationship between acetaminophen and autism.

“Acetaminophen is one of the few options available to pregnant patients to treat pain and fever, which can be harmful to pregnant people when left untreated,” American College of Obstetricians and Gynecologists president Dr. Steven J. Fleischman said in the statement.

The group also noted that reviews in 2015 and 2017 from the FDA and the Society for Maternal-Fetal Medicine respectively found no risks associated with appropriate usage of the drug in pregnancy.

How to navigate government communications around Tylenol use

Nonetheless, the mixed messaging from the Trump administration about Tylenol seems likely to continue.

The Department of Health and Human Services this week reposted a 2017 tweet from the Tylenol brand’s account that said, “We actually don’t recommend using any of our products while pregnant.”

A spokesperson for Kenvue, the company that owns Tylenol, said the post was taken out of context and incomplete.

“Consistent with regulations, our label states clearly ‘if pregnant or breast-feeding, ask a health professional before use,’ ” Melissa Witt said in an email. “We do not make recommendations on taking any medications in pregnancy because that is the job of a healthcare provider.”

Vice President JD Vance offered similar guidance this week.

“My guidance to pregnant women would be very simple, which is follow your doctor. Right?” Vance said in an interview with the outlet NewsNation after Trump’s press conference. “Talk to your doctor about these things.”