Valproate use during pregnancy was linked to autism spectrum disorder and childhood autism in offspring.

Main results 0.40% of children were exposed to antiepileptic drugs during pregnancy; 0.08% were exposed to valproate. 0.83% of children were diagnosed with autism spectrum disorder during follow-up, including 0.32% with childhood autism. Use of valproate during pregnancy was associated with increased risk for autism spectrum disorder and childhood autism in offspring (Table). Other antiepileptic drugs used as monotherapy during pregnancy were not associated with increased risk for autism spectrum disorder (oxcarbazepine, adjusted hazard ratio [aHR] 2.1, 95% CI 0.96 to 4.6; lamotrigine, aHR 1.7, CI 0.8 to 3.5; clonazepam, aHR 0.7, CI 0.2 to 2.9; carbamazepine, aHR 1.0, CI 0.4 to 2.8) or childhood autism (oxcarbazepine, aHR 1.0, CI 0.1 to 6.9; lamotrigine, aHR 1.7, CI 0.5 to 5.2; clonazepam, aHR 0.9, CI 0.1 to 6.7; carbamazepine, aHR 1.4, CI 0.4 to 5.8) in offspring compared with no use of the specific monotherapy. Conclusion Maternal use of valproate during pregnancy was associated with increased risk for autism spectrum disorder and childhood autism in offspring.