Common Pregnancy Medications Linked to Higher Autism Risk in Massive U.S. Study

Prenatal use of certain common medications may raise autism risk, especially when multiple drugs are combined. Findings highlight the need for caution and further research.

A major study led by researchers at the University of Nebraska Medical Center (UNMC) and published in Molecular Psychiatry reports a strong link between medications commonly prescribed during pregnancy and an increased risk of autism spectrum disorder (ASD) in children.

The researchers reviewed 6.14 million maternal-child health records from the Epic Cosmos database, which covers nearly one-third of all U.S. births between 2014 and 2023. They found that drugs known to disrupt the body’s cholesterol production pathway were consistently tied to higher rates of ASD in children.

Cholesterol Pathway–Inhibiting Drugs Identified

Instead of grouping medications by their intended use, as earlier research has done, the UNMC team classified drugs based on their shared impact on sterol biosynthesis, including both direct effects and side effects.

This group of sterol biosynthesis-inhibiting medications (SBIMs) includes certain antidepressants, antipsychotics, anxiolytics, beta-blockers, and statins. The 15 drugs examined were aripiprazole, atorvastatin, bupropion, buspirone, fluoxetine, haloperidol, metoprolol, nebivolol, pravastatin, propranolol, rosuvastatin, sertraline, simvastatin, cariprazine, and trazodone. Many of these are widely prescribed in the United States, with more than 400 million prescriptions filled each year.

Key Findings

• Pregnant individuals who were prescribed at least one SBIM had a 1.47 times higher likelihood of having a child diagnosed with ASD. The risk rose with greater exposure. Each additional SBIM increased the risk by 1.33 times, reaching a 2.33 times higher risk when four or more were used at the same time.
• Of the 234,971 children in the study diagnosed with ASD, 15% had been exposed to SBIMs before birth.
• Use of these medications during pregnancy has also increased significantly, from 4.6% of pregnancies in 2014 to 16.8% in 2023.

Importance of Cholesterol in Fetal Development

Cholesterol plays a critical role in fetal development, particularly for the brain, which contains more cholesterol than any other organ. The fetal brain begins producing its own sterols at about 19–20 weeks of gestation. Disruptions in this pathway can lead to serious developmental conditions such as Smith-Lemli-Opitz syndrome (SLOS), in which up to 75% of affected children meet criteria for ASD.

Many commonly used medications can interfere with this biological process. This study is the first nationwide effort to examine how prenatal exposure to this class of drugs may influence neurodevelopmental outcomes.

Expert Caution and Medical Guidance

“Our findings do not suggest that these medications are unsafe for adults,” said corresponding author Karoly Mirnics, MD, PhD, dean and director of the UNMC Munroe-Meyer Institute. “But they raise important questions about their use during pregnancy, a period when even small biochemical disruptions may have outsized effects on fetal brain development.”

The researchers emphasize that pregnant patients should not stop or change medications without guidance from a healthcare provider, since many SBIMs are necessary and can be life-saving. Instead, the findings highlight the need to reassess prescribing practices and develop safer options for use during pregnancy.

Recommendations for Safer Prescribing Practices

The team recommends several steps to improve medication safety for pregnant patients:

• Develop a comprehensive list of drugs that affect sterol pathways.
• Screen all new medications for unintended interference with cholesterol synthesis.
• Improve provider awareness of how medications may disrupt sterol processes during pregnancy.
• Consider safer alternatives when stopping treatment is not an option.
• Limit the use of multiple SBIMs during pregnancy when possible.
• Identify patients with genetic risks affecting sterol metabolism, who may be more vulnerable.
• Support further research to better understand these mechanisms and reduce risk.

Reference: “Sterol pathway disruption in pregnancy: a link to autism” by Eric S. Peeples, A. Jerrod Anzalone, Ran Dai, Elizabeth Reisher, Zeljka Korade and Karoly Mirnics, 16 April 2026, Molecular Psychiatry.
DOI: 10.1038/s41380-026-03610-7

The work was conducted using the Epic Cosmos national data platform and included collaboration among UNMC’s Department of Pediatrics, Department of Biostatistics, Munroe-Meyer Institute, other UNMC departments and the Child Health Research Institute (CHRI). The study received support from UNMC/CHRI internal resources, the Dorothy B. Davis Foundation and the Nebraska Tobacco Settlement Fund.

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