New Guidelines Recommend Avoiding Acetaminophen During Pregnancy and After Shots; Propose Adjustments to Childhood Vaccine Schedules

Washington, D.C. – September 23, 2025

President Donald Trump and Health and Human Services Secretary Robert F. Kennedy Jr. outlined new recommendations on Monday to address rising autism rates, focusing on the roles of acetaminophen – the active ingredient in Tylenol – and certain vaccination protocols.

During a White House briefing, Trump stated, "We've got the science now – Tylenol during pregnancy, Tylenol after shots, too many vaccines too soon – these are causing our kids' autism crisis." He advised pregnant women to avoid the pain reliever and parents to forgo prophylactic doses of acetaminophen following vaccinations to manage fever and discomfort.

Kennedy pointed to research linking increased acetaminophen use since the 1980s to higher autism diagnoses, particularly when administered to infants after routine shots like the MMR vaccine. A 2016 study identified an association between post-MMR acetaminophen use for fever and elevated autism rates, reporting odds ratios up to 6.1 in certain children.

The administration referenced acetaminophen's effects on prostaglandin synthesis and oxidative stress, which may heighten immune responses in developing brains, especially in boys with slower metabolism of the drug. Kennedy noted that the timing of acetaminophen after vaccines correlates with patterns of autism onset.

In response, the FDA has begun updating labels for acetaminophen products to warn of potential autism risks during pregnancy. This follows a 2025 meta-analysis of 46 studies indicating an association with autism and ADHD. A Mount Sinai study from August 2025 further supported that prenatal exposure to acetaminophen may raise the risk of autism and ADHD in children. A Harvard study released in August 2025 found that children exposed to acetaminophen in utero are more likely to develop autism and ADHD.

A 2024 JAMA study of a large population also detected marginally increased risks of autism linked to prenatal acetaminophen use.

On vaccines, the administration proposed delaying the hepatitis B vaccine from birth until age 12 and administering MMR components separately to minimize immune system load. Trump highlighted the prior removal of thimerosal, a mercury-based preservative, from most vaccines.

Additionally, the administration endorsed leucovorin, a folic acid derivative, for autism treatment, committing to Medicaid coverage and increased production. Early trials indicate potential for symptom improvement.

With autism affecting 1 in 36 U.S. children, these measures aim to reduce incidence through evidence-based adjustments.