A large study published this week in the journal Molecular Psychiatry is drawing serious attention from researchers and clinicians alike. The findings suggest that certain medications taken during pregnancy may be associated with a higher likelihood of autism spectrum disorder (ASD) diagnosis in children, particularly when multiple of those medications are used at once.
For families already living with an autism diagnosis, or for expectant parents trying to understand the research landscape, here is what the study actually found and what it does not claim.
What the Study Looked At
Researchers analyzed health records from more than six million children born in the United States between 2014 and 2023, drawing from the Epic Cosmos database, which pulls de-identified data from over 1,800 hospitals and 42,000 clinics nationwide. Each child had at least 18 months of follow-up after birth.
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The team focused on a specific class of medications called sterol biosynthesis inhibiting medications, or SBIMs. These are drugs that interfere with the body's ability to produce cholesterol through normal biological pathways. The list includes some widely prescribed medications, among them certain antidepressants like sertraline and fluoxetine, antipsychotics like aripiprazole and haloperidol, and cholesterol-lowering statins like atorvastatin and simvastatin.
About 11 percent of mothers in the dataset were prescribed at least one of these medications during pregnancy.
The Cholesterol Connection
The biological reasoning behind the study is worth understanding, because it reframes how we think about fetal brain development.
Cholesterol is not just a number on a blood panel. It is a foundational building block for cell membranes and plays a critical role in how the fetal brain develops. Early in pregnancy, the mother supplies cholesterol to the developing baby. By mid-pregnancy, the fetal brain begins producing its own. If that production process gets disrupted, whether by a genetic mutation or an outside factor, the consequences can be significant.
Researchers have long studied Smith-Lemli-Opitz syndrome (SLOS), a genetic condition that blocks a key step in cholesterol synthesis. About 75 percent of people with SLOS are also diagnosed with autism. That overlap is part of what motivated this study: if a genetic disruption to the cholesterol pathway is so frequently associated with autism, what happens when medications cause a similar disruption during pregnancy?
What the Data Showed
Among the 6 million children studied, 3.8 percent received an ASD diagnosis. Children whose mothers had been prescribed at least one SBIM during pregnancy showed a higher rate of ASD diagnosis than those with no exposure.
The more striking finding was the cumulative effect. With each additional SBIM prescribed during pregnancy, the associated risk of ASD increased by roughly 1.33 times. Mothers prescribed four or more of these medications saw children with more than twice the baseline risk of an ASD diagnosis. One specific medication, cariprazine, was associated with more than double the observed ASD risk on its own.
For comparison, the researchers also tracked a set of medications commonly prescribed in pregnancy that do not affect sterol biosynthesis, including ondansetron and famotidine. Those medications showed minimal increases in ASD risk, and the associations nearly disappeared after additional analysis. That contrast gives the sterol pathway hypothesis more credibility, though it still does not prove causation.
What This Does Not Mean
This is an observational study. It can identify associations, but it cannot tell us definitively that these medications cause autism. That distinction matters enormously.
Mothers who were prescribed multiple SBIMs during pregnancy often had higher rates of underlying metabolic and psychiatric conditions. Those conditions themselves may contribute to developmental outcomes in children. The researchers adjusted for many of these factors, but acknowledged that some unmeasured variables remain. Sensitivity analyses that accounted for maternal psychiatric diagnoses did reduce some of the associations, particularly around psychotropic medications, though the overall signal held.
The researchers are also careful to note that many of these medications are essential treatments. A pregnant person managing depression, bipolar disorder, or a seizure condition should not stop their medication based on a single study. The risks of untreated mental illness during pregnancy are real and well-documented.
What Clinicians Are Being Asked to Do
The study's authors recommend that prescribers take a harder look at how SBIMs are used during pregnancy, specifically around combinations of these drugs. Their suggestions include seeking safer alternatives where clinically reasonable, limiting the number of SBIM-class medications prescribed simultaneously, and considering whether a patient's genetic profile could increase sensitivity to these effects.
They also call for more research. Factors like dosage, timing of exposure during pregnancy, and individual genetic variation were not measured in this study. Those details could be the difference between a meaningful risk factor and a manageable one.
Why This Matters for the Special Needs Community
For families in the autism community, research like this raises hard questions. Some parents will wonder whether a medication taken during pregnancy played a role in their child's diagnosis. That kind of reflection can be painful, and it is important to sit with what the science actually says: this study found an association, not a cause.
What it does offer is a sharper question for future research and a concrete reason for clinicians to be more intentional about prescribing during pregnancy. For families planning a pregnancy, it is one more reason to have an open, detailed conversation with an OB or a maternal-fetal medicine specialist about every medication currently being taken.
Autism is shaped by a complex web of genetic, biological, and environmental factors. No single study changes that picture entirely. But this one adds a piece worth paying attention to.