Paternal valproate exposure and child neurodevelopment: What this Taiwan study found

What was studied

This nationwide Taiwan study included 2,583,503 people born from 2001 through 2016 and followed through 2021. Researchers examined whether a father's use of valproate or other antiseizure medicines during the 3 months before conception was associated with neurodevelopmental disorders or congenital malformations in his children.

There were 1,701 children with paternal valproate exposure. Researchers also analyzed 548 sibling sets in which exposure differed between pregnancies, helping control for genetic and lifestyle factors shared by siblings.

What they found

Paternal valproate use was not associated with an increased recorded risk of autism, ADHD, intellectual disability, tic disorders, or congenital malformations. The findings remained similar when the analysis was limited to children of fathers with epilepsy and when siblings with different exposure status were compared.

A few associations for other antiseizure medicines reached nominal statistical significance in the population analysis, but none remained in the sibling-comparison analyses.

Limits of the evidence

This was an observational cohort study, so it cannot establish that paternal valproate exposure is completely risk-free or that the medicines caused or prevented any outcome. Although the overall cohort was large, 1,701 children had paternal valproate exposure, and the sibling analysis included 548 sets. The confidence intervals mean that some differences in risk cannot be ruled out. Outcomes were identified from outpatient and inpatient medical records, and the abstract does not report results by dose, treatment duration, or specific other antiseizure medicine.

For families and caregivers

These findings may be reassuring because the study did not find an increased risk of the studied neurodevelopmental disorders or congenital malformations after paternal valproate use during sperm development. However, the authors state that additional evidence is needed before conclusions are drawn about changing current treatment practices.

What to watch next

Additional studies in different populations, including studies with more exposed children and details about dose and individual medicines, could help clarify the evidence. Treatment decisions should be discussed with the prescribing clinician.

Terms in this summary

Valproate

An antiseizure medicine.

Spermatogenesis

The process of producing sperm; this study defined the relevant exposure period as the 3 months before conception.

Neurodevelopmental disorders

Conditions involving brain development, including autism, ADHD, intellectual disability, and tic disorders in this study.

Congenital malformations

Structural differences in the body that are present at birth.

Sibling comparison

A method that compares siblings with different exposures to reduce the influence of genetic and lifestyle factors they share.

Hazard ratio

A measure comparing how often an outcome occurs over time between groups; a value near 1 indicates similar estimated rates.

Odds ratio

A measure comparing the odds of an outcome between groups; a value near 1 indicates similar estimated odds.

Confidence interval

A range showing the uncertainty around an estimated result; wider ranges indicate greater uncertainty.