Prenatal Tylenol Use Drops, Leucovorin Prescriptions Surge - Medscape

Acetaminophen orders for pregnant patients declined while pediatric prescriptions for leucovorin soared following a September 2025 White House briefing on autism that included debunked or unproven claims about the two drugs, a new analysis suggests.

As reported by* Medscape Medical News*, federal officials speaking at the briefing urged pregnant women to avoid acetaminophen (paracetamol), selectively citing debunked research purporting to link prenatal use and subsequent neurodevelopmental disorders, including autism.

In addition, US Department of Health and Human Services Secretary Robert F. Kennedy, Jr, said his agency had identified leucovorin calcium as “an exciting therapy” that may benefit children with autism and that he had asked the manufacturer to submit a supplemental new drug application to update the label for that indication.

In the weeks after the briefing, acetaminophen orders for pregnant patients treated in US emergency departments declined by 10%, while new leucovorin prescriptions for children increased by 71%, the researchers found.

It’s unknown whether this reflects changes in patient demand or clinician decision-making; “nonetheless, they show the apparent power that public authority figures have to drive sudden changes in healthcare practices,” wrote Jeremy Faust, MD, MS, with Mass General Brigham and Harvard Medical School in Boston, and Michael Barnett, MD, MS, with Brown University School of Public Health in Providence, Rhode Island.

For the analysis, published online on March 5 in The Lancet, researchers used an electronic health record database to identify emergency department (ED) orders for acetaminophen and new outpatient prescriptions for leucovorin. The database includes more than 294 million patient records from over 1600 hospitals and 37,000 clinics.

During the post-briefing period (September 22-December 7, 2025), there were 88,857 ED visits among pregnant women aged 15-44 years, 853,216 visits among nonpregnant women in the same age group, and more than 8.6 million outpatient encounters among children aged 5-17 years.

Among the pregnant ED patients, acetaminophen orders fell by 10% after the briefing, corresponding to an absolute rate change of 22.5 orders per 1000 visits. The decline was largest during the first month after the briefing, with a 16% decrease and a maximal change of 20% during the third week post-briefing.

In contrast, there was no statistically significant change in ED acetaminophen use among nonpregnant patients aged 15-44 years, nor among two comparator prescription drugs (opioids and sodium lactate), regardless of pregnancy status.

Reduced acetaminophen use during pregnancy could lead to more untreated fevers — which have been linked to neurologic risks in offspring — or encourage use of alternative medications that may be less safe during pregnancy, Faust and Barnett noted.

In the leucovorin analysis, new outpatient prescriptions for children aged 5-17 years jumped 71% after the briefing, corresponding to an absolute rate change of 17.5 prescriptions per 100,000 visits. An initial increase of 93% was observed in the first month after the briefing.

In contrast, for the leucovorin comparators, there was no statistically significant change in outpatient folic acid prescriptions, while prescriptions for aripiprazole and risperidone — both approved for children with autism — showed smaller increases, which largely occurred late in the study period.

An increase in leucovorin prescriptions outside the rare condition of cerebral folate deficiency might confer false expectations and lead to unnecessary side effects, the researchers noted.

Earlier this week, the FDA approved expanded use of leucovorin calcium tablets not for autism, but for an ultra-rare brain disorder that can have similar symptoms.

The researchers cautioned that while causal claims cannot be made, the findings in this analysis are “consistent with influence of new FDA recommendations on clinical decisions.”

The study had no specific funding. Faust and Barnett had no relevant disclosures.