New study points to possible link between commonly used drugs in pregnant women and autism risk

A recent study by the University of Nebraska Medical Center (UNMC) and the Dorothy B. Davis Foundation, published in the journal Molecular Psychiatry, suggests that the use of certain drugs that inhibit sterol biosynthesis - a pathway involved in cholesterol production - during pregnancy may be associated with an increased risk of autism spectrum disorder (ASD) in children.

The analysis, one of the largest conducted to date in this field, examined the medical records of more than 6.1 million children born between 2014 and 2023, along with complete data from their mothers. The information comes from the Epic Cosmos database, which compiles records from more than 1,880 hospitals and 42,400 clinics in the country, tracking the children through December 2025.

More drug exposure, higher risk observed in offspring

Of the more than 234,000 children diagnosed with autism spectrum disorder in the study, 15.0% of the mothers were prescribed at least one of these drugs during pregnancy.

The results show that women who were prescribed one of these drugs during pregnancy had a 1.47-fold increased risk of having their child diagnosed with ASD, after adjusting for potential confounds.

According to the researchers, the risk increased consistently as the number of such medications taken by the mother grew: "The risk increased by 1.33 times (1.32–1.34) for each additional sterol biosynthesis inhibitor (SBIM) during pregnancy." The study yielded that in adjusted analyses, "risk reached as high as 2.33-fold (2.09–2.60) with 4 SBIMs."

"We propose that the use of [sterol biosynthesis inhibitors] during pregnancy may increase the risk of ASD in offspring through a multistep biochemical cascade," the researchers wrote.

The role of cholesterol in neurodevelopment, under scientific review

Drugs that inhibit sterol biosynthesis partially block the natural production of cholesterol, a substance essential for fetal brain development.

According to researchers at the University of Nebraska, alterations in this pathway are linked to syndromes such as Smith-Lemli-Opitz, in which about 75% of those affected are also diagnosed with ASD.

Previous studies had detected cases of patients with features of the syndrome without genetic mutations, but who had taken the antipsychotic aripiprazole or the antidepressant trazodone, both sterol biosynthesis inhibitors.

Limitations and recommendations

The study is observational and cannot establish definitive causality nor rule out all environmental or other contributing factors. The authors excluded cases with valproic, known to cause fetal anomalies, and emphasized that the findings apply only to use during pregnancy.

"Our findings do not suggest that these medications are unsafe for adults," said Dr. Károly Mirnics, dean and director of the Munroe-Meyer Institute at UNMC. "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."