Common Meds Taken During Pregnancy Linked To Higher Autism Risk In Children, Major Study Finds

From Antidepressants To Statins, 15 Widely Prescribed Drugs Share A Concerning Biological Side Effect

A study of more than six million births across the United States has uncovered a surprising connection between fifteen widely prescribed medications and autism risk in children. The drugs span several categories, from popular antidepressants to heart medications to cholesterol-lowering statins. What the researchers argue ties them together isn’t the condition they treat, but something happening at the cellular level: all fifteen can interfere with the body’s ability to produce cholesterol.

Cholesterol has a bad reputation in the adult world, where it clogs arteries and drives heart disease. But for a developing fetus, cholesterol is a building block for every cell in the body. It is especially critical for the brain, the most cholesterol-rich organ we have. Around the midpoint of pregnancy, the fetal brain begins manufacturing its own cholesterol supply. Disrupting that process, the researchers argue, could set the stage for developmental problems that show up years later.

Published in Molecular Psychiatry, the study found that exposure to at least one of these cholesterol-disrupting medications during pregnancy was associated with a 47% relative increase in the risk of an autism diagnosis in the child. The more of these drugs a pregnant woman was prescribed at the same time, the higher the risk climbed, reaching more than double the baseline risk when four or more were taken at once.

Notably, the share of pregnant women prescribed at least one of these medications more than tripled over the study period, rising from 4.6% in 2014 to 16.8% in 2023.

How the Pregnancy Medication and Autism Risk Study Worked

Researchers at the University of Nebraska Medical Center used a massive electronic health records database called Epic Cosmos, which draws from more than 300 million patient records across over 1,880 hospitals and 42,400 clinics nationwide. They identified pairs of linked maternal and child health records for births between 2014 and 2023, following children through early 2026. After applying their criteria, requiring at least 18 months of follow-up for each child and excluding certain cases, they had 6,135,213 mother-child pairs to analyze. That group represents nearly one-third of all births in the country during that decade.

The team focused on fifteen medications that prior lab research had shown to interfere with cholesterol production in cells. They included:

• Sertraline
• Fluoxetine
• Bupropion
• Buspirone
• Aripiprazole
• Cariprazine
• Haloperidol
• Trazodone
• Metoprolol
• Propranolol
• Nebivolol
• Atorvastatin
• Simvastatin
• Rosuvastatin
• Pravastatin

About 699,692 pregnant women, or 11% of the group, were prescribed at least one of these medications. Among the more than six million children in the study, 234,971 (3.8%) received an autism diagnosis. Of those children diagnosed with autism, 15% had mothers who were prescribed at least one of these cholesterol-disrupting drugs during pregnancy.

A Dose-Response Pattern Strengthens the Pregnancy Medication and Autism Link

What bolstered the researchers’ case was the pattern they observed when women took multiple medications. Each additional cholesterol-disrupting drug prescribed during pregnancy was associated with a 1.33-fold increase in autism risk. When four or more were prescribed at the same time, the risk reached 2.33 times higher than the baseline. This stacking effect, the team noted, lines up with earlier lab work showing that combining several of these medications further raised levels of a potentially toxic byproduct in pregnant women’s blood.

The drug tied to the single highest risk was cariprazine, an antipsychotic, which showed a 2.59-fold increased risk of autism after adjusting for other factors. Across all fifteen medications, the strength of the autism association tracked closely with how powerfully each drug had been shown in prior lab studies to block a specific step in cholesterol production.

To check that the pattern was specific to these cholesterol-disrupting drugs and not just a general effect of taking any medication during pregnancy, the researchers ran the same analysis on six commonly prescribed prenatal medications with no known effect on cholesterol production, including treatments for allergies, constipation, acid reflux, iron deficiency, and nausea. Those medications showed only minimal associations with autism risk, with adjusted risk increases ranging from just 2% to 17%, far below what was seen with the cholesterol-disrupting drugs.

Ruling Out Other Explanations

One obvious concern is that the underlying condition being treated, not the medication itself, might be driving the association. Depression, anxiety, bipolar disorder, and schizophrenia all have genetic components, and some of those genetic factors might independently raise a child’s risk of autism. The researchers addressed this directly and ran extensive additional analyses that accounted for maternal mental health diagnoses.

Those extra analyses did reduce the strength of the association for some psychiatric medications. For aripiprazole, the adjusted risk dropped from 2.18-fold to 1.31-fold after accounting for psychiatric diagnoses. But medications prescribed for non-psychiatric reasons were barely affected. Simvastatin’s risk only shifted from 1.64-fold to 1.57-fold, and pravastatin moved from 1.95-fold to 1.73-fold. The authors argue that drugs spanning entirely different medical uses, from antidepressants to heart medications to cholesterol drugs, all showing elevated risk supports a shared biological mechanism, though they acknowledge that confounding by the underlying conditions remains a concern and cannot be fully ruled out.

To explain the biological mechanism, the researchers proposed a specific chain of events. When these medications block steps in the cholesterol production pathway, the body accumulates an intermediate molecule called 7-DHC. This molecule is extremely prone to breaking down into toxic byproducts that can damage cells and interfere with how brain cells develop and connect.

A rare genetic condition called Smith-Lemli-Opitz syndrome offers a telling parallel. Caused by mutations that disrupt the same final step of cholesterol production these drugs affect, the syndrome results in a buildup of 7-DHC and a shortage of cholesterol. Roughly 75% of children with this condition are diagnosed with autism. According to the research team, the medications in this study may be creating a milder, drug-induced echo of the same biological disruption, though they present this as a proposed mechanism rather than a proven one.

What This Means for Millions of Pregnancies

The public health stakes are substantial. The medications examined in this study account for approximately 400 million prescriptions annually in the United States, and nine of the fifteen drugs rank among the top 25 most prescribed medications in the country. Statins, which had long carried warnings against use during pregnancy due to potential risks to fetal development, saw that warning removed by the FDA in 2021, even as their use among pregnant women was already climbing.

The researchers offered seven specific recommendations, including creating a full catalog of all medications known to interfere with cholesterol production, systematically testing new drugs for this side effect, educating providers and patients about the risks, limiting the practice of prescribing multiple cholesterol-disrupting drugs at the same time during pregnancy, and investing in further research.

They also cautioned strongly against overreacting. These medications are lifesaving treatments for adults and should not be abandoned without consulting a doctor. In adults, whose brains are fully formed, cholesterol turns over slowly and is unlikely to be meaningfully disrupted by these drugs.

Still, the message is direct: what is safe for a grown adult may not be safe for the rapidly developing brain of a fetus. With millions of pregnancies potentially affected each year, the authors argue their findings warrant a closer look at how these drugs are prescribed to expectant mothers.

Disclaimer: This article summarizes findings from observational research and should not be interpreted as medical advice. The study reports an association between certain medications prescribed during pregnancy and autism diagnoses in children, not a proven causal relationship. The researchers emphasize that the medications examined are lifesaving treatments for many adults and caution strongly against discontinuing any prescribed medication without consulting a qualified healthcare provider. Pregnant women and those planning pregnancy should discuss all medications and potential risks with their doctor before making any changes to their treatment regimen.