Men who use the antiseizure drug valproate in the months before their partner conceives do not appear to raise their child's risk of autism, ADHD or major birth defects. That is the message from a large new analysis of more than 2.5 million children in Taiwan. The finding pushes back against a recent European warning that had tightened prescribing for younger men.
The research, published in the journal Neurology on August 19, 2026, drew on the Taiwan National Health Insurance Research Database. Of 2,583,503 children born over a 15-year window, 1,701 had fathers prescribed valproate in the three months before conception, the period when sperm are formed.
Children were tracked for an average of 12 years. Raw rates were slightly higher in the exposed group. About 1.9 percent were diagnosed with autism versus 1.6 percent overall, and 10.2 percent with ADHD versus 7.7 percent. Rates of tic disorders, intellectual disability and malformations at birth showed similar small gaps.
Why the small differences melted away
Those unadjusted numbers can mislead. After the researchers accounted for sex, birth weight, parental age, pregnancy complications and a maternal history of epilepsy or psychiatric disorders, the extra risk disappeared. Sibling comparisons across 548 families and separate analyses of other antiseizure medicines pointed the same way.
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"While such drugs have been extensively studied in mothers, less is known about use of these drugs by fathers," said study author Shi-Heng Wang, PhD, of the National Health Research Institutes in Zhunan, Taiwan. He added that the Taiwan analysis found no increased risk of disorders or malformations among children of fathers prescribed valproate or other antiseizure medications.
Why paternal use became a question
Valproate, sold under brand names including Depakote, is used for epilepsy, bipolar disorder and migraine prevention. It has long carried strong warnings for use in pregnancy, where it is tied to neural tube defects and lower IQ in exposed children. Concerns about the father's role are much newer.
In 2024, the UK's Medicines and Healthcare products Regulatory Agency told doctors not to start men aged 55 or younger on valproate without two-specialist sign-off, citing a European study in which around 5 out of 100 children had a neurodevelopmental disorder when born to fathers treated with valproate compared with around 3 out of 100 whose fathers used alternatives. The agency also urged male patients and their partners to use effective contraception during treatment and for three months after stopping.
Wang argued that the Taiwan numbers should feed into that debate, and said more research is needed before regulators change current prescribing.
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What the study does not settle
The reassurance comes with a caveat the authors flagged themselves. Some children were followed for as little as five years, so diagnoses that tend to surface later, such as ADHD or milder learning difficulties, may have been missed. Longer follow-up is needed to be certain.
The nuance about mothers still stands. Valproate taken during pregnancy remains among the highest-risk medications for the developing fetus, and guidelines discourage its use in people who can become pregnant unless no alternative works. The new study speaks only to men and only to the period before conception.
For men on valproate who are thinking about starting a family, the practical takeaway from the researchers is straightforward. Any change to antiseizure medication belongs in a conversation with a treating neurologist, because uncontrolled seizures carry their own serious risks for both patient and pregnancy.
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This article is made and published by Jesper Bengtson, who may have used AI in the preparation.