Teratogenic risk of carbamazepine, levetiracetam, and lamotrigine treatment in pregnant women with epilepsy.

OBJECTIVE: Antiseizure medications used during pregnancy may exert teratogenic effects on the developing fetus, with risks varying according to drug type, dosage, and exposure timing. While older agents such as carbamazepine are associated with known risks, newer agents including lamotrigine and levetiracetam have demonstrated more favorable safety profiles. This study aimed to evaluate pregnancy outcomes, major congenital malformation rates, and seizure frequency in pregnant women with epilepsy exposed to carbamazepine, lamotrigine, or levetiracetam as monotherapy or polytherapy, compared with an untreated control group. METHODS: This retrospective observational study included pregnant women with epilepsy who were categorized into antiseizure medication-exposed (monotherapy or polytherapy) and non-exposed groups. Clinical data, including seizure history, medication type and dosage, pregnancy outcomes, and neonatal findings, were collected. major congenital malformations were identified according to European Surveillance of Congenital Anomalies criteria. RESULTS: A total of 307 pregnancies were analyzed, resulting in 276 live births. major congenital malformation rates were 6.1% for carbamazepine, 1.7% for levetiracetam, and 3.6% for lamotrigine monotherapy. Polytherapy outcomes varied by combination, with relatively low risks observed in levetiracetam-containing regimens. Seizure frequency remained unchanged in most cases (69.6%), increased in 21%, and decreased in 9.4% of pregnancies. Preconception seizure presence significantly increased the risk of seizures during pregnancy. CONCLUSION: Levetiracetam and lamotrigine demonstrate favorable safety profiles, whereas carbamazepine carries a moderate teratogenic risk. Polytherapy risk is combination-dependent, and preconception seizure control is a key predictor of seizure outcomes during pregnancy.