In a population-based cohort study by Razaz et al,1 risks of neurodevelopmental disorders in 2051 children of fathers taking valproate monotherapy during spermatogenesis were no different to those taking levetiracetam or lamotrigine. The authors demonstrate how this aligns with several other population-based studies cited2–4 and a systematic review.5 An international study in 91 917 men taking valproate found no difference in fertility compared to unexposed men with the same health conditions.6 These studies illustrate well-designed and conducted analyses of large datasets.

This has significant implications. UK regulators currently require two specialist reviews and sign-offs for males <55 years commencing valproate and recommend male and female contraception to avoid conceiving children while taking it. This means that men electing to take valproate lifelong are advised not to have children. This is based on ‘signals’ from animal studies. There is strong…