Purpose: To investigate pregnancy, delivery, and child outcome in an unselected population of women with both treated and untreated epilepsy.
Methods: In the compulsory Medical Birth Registry of Norway, all 2,861 deliveries by women with epilepsy recorded from 1999–2005 were compared to all 369,267 nonepilepsy deliveries in the same period.
Results: The majority (66%, n = 1900) in the epilepsy group did not use antiepileptic drugs (AEDs) during pregnancy. A total of 961 epilepsy-pregnancies were exposed to AEDs. Compared to nonepilepsy controls, AED-exposed infants were more often preterm (p = 0.01), and more often had birth weight <2,500 g (p < 0.001), head circumference <2.5 percentile (p < 0.001), and low Apgar score (p = 0.03). Small-for-gestational-age (SGA) infants (<10 percentile) occurred more frequently in both AED-exposed (p = 0.05) and unexposed (p = 0.02) epilepsy-pregnancies. Frequency of major congenital malformations (MCMs) was 2.8% (n = 81) in the epilepsy group versus 2.5% in controls (p = 0.3). Increased risk for MCMs could be demonstrated only for exposure to valproate (5.6%, p = 0.005) and AED polytherapy (6.1%, p = 0.02). Neonatal spina bifida was not significantly increased, but was a major indication for elective pregnancy termination among women with epilepsy. Cesarean section was performed more often in maternal epilepsy, regardless of AED-exposure (p < 0.001).
Discussion: Adverse pregnancy and birth outcome in women with epilepsy is mainly confined to AED-exposed pregnancies, although some risks are associated also with untreated epilepsy. The risk for congenital malformations was lower than previously reported. This could be due to a shift in AED selection, folic acid supplement, or possibly reflect the true risks in an unselected epilepsy population.