Valproate-associated foetal malformations-Rates of occurrence, risks in attempted avoidance

Area of Science:

• Obstetrics and Gynecology
• Neurology
• Pharmacology

Background:

• Valproate is a widely used antiepileptic drug.
• Concerns exist regarding valproate's teratogenic potential.
• Limited data available on the risks of discontinuing valproate before pregnancy.

Purpose of the Study:

• To evaluate the risks and benefits of valproate use in pregnancy.
• To assess the impact of valproate unavailability for pregnant women.
• To analyze the consequences of ceasing valproate therapy prior to conception.

Main Methods:

• Analysis of Australian Pregnancy Register data.
• Comparison of pregnancies exposed to valproate (N=501) with those where valproate was ceased before pregnancy (N=101).

Main Results:

• Valproate exposure during pregnancy is dose-dependently linked to fetal malformations, with higher doses correlating with severe malformations like spina bifida.
• Approximately 80% of fetal malformations might have been preventable by avoiding valproate exposure.
• Discontinuing valproate before pregnancy increased the risk of seizure-affected pregnancies, especially in women with generalized epilepsies (50% to nearly 100% incidence increase).

Conclusions:

• Avoiding valproate in pregnancy reduces fetal malformation rates but can compromise maternal epilepsy management.
• Individualized treatment decisions are crucial, considering valproate's prevalence in generalized epilepsy and risks associated with withdrawal.
• This study provides a quantitative framework for balancing the benefits and risks of valproate for women with epilepsy planning pregnancy.