A large Taiwanese study suggests that fathers’ use of valproate before conception does not increase the risk of autism, ADHD, or birth defects in their children, challenging previous concerns about paternal medication exposure.
A large Taiwanese study has found that fathers’ use of valproate in the months before conception was not linked to a higher risk of autism, ADHD or other neurodevelopmental disorders in their children, and it did not appear to raise the chance of birth defects, according to research published on 19 August 2026 in Neurology, the journal of the American Academy of Neurology. The findings matter because valproate, a widely used antiseizure medicine, has long been associated with serious harm when taken by women during pregnancy. Study author Shi-Heng Wang of the National Health Research Institutes in Taiwan said: “People with epilepsy need long-term treatment to control seizures, including during their reproductive years,” adding that while the drug has been studied extensively in mothers, far less has been known about paternal exposure.
The research team analysed Taiwan’s national health insurance database and followed more than 2.5 million children born over a 15-year period. Among the children studied, 1,701 had fathers who had taken valproate in the three months before conception, the period when sperm is developing. After accounting for factors including parental age, birth weight, pregnancy complications and maternal epilepsy or psychiatric history, the researchers found no clear association between paternal valproate use and autism, ADHD, tic disorders, intellectual disability or congenital malformations. A sibling comparison produced similar results, and the same pattern was seen with other common antiseizure medicines.
The findings add to a mixed but increasingly important evidence base. A living meta-analysis in the Journal of Neurology, Neurosurgery, and Psychiatry also reported no significant link between paternal valproate use during spermatogenesis and neurodevelopmental disorders in offspring. But a separate study in JAMA Network Open found a higher risk of neurodevelopmental disorders when valproate was compared with lamotrigine or levetiracetam, even though it did not find a difference in malformation rates. Wang said a recent UK warning against valproate use in men aged 55 and under was based on European studies and that more data are still needed before prescribing advice changes. The Taiwanese authors also noted that follow-up was shorter for some children, meaning later diagnoses may have been missed.
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