Factors influencing the risk of abnormal pregnancy outcome in epileptic women: a multi-centre prospective study.

We studied pregnancy outcome in preconceptionally recruited epileptic and control women in a multi-centre prospective non-intervention study at two university hospitals and three general hospitals. We evaluated 225 singleton pregnancies: 119 pregnancies of epileptic women who received either antiepileptic drugs (AEDs) (n = 99) or not (n = 20), and 106 pregnancies of controls. The main outcome measures were abnormal pregnancy outcome: major and minor congenital malformations, ectopic pregnancies, abortions; neonatal headcircumference; birth weight and birth length. Epileptic women had a two-fold risk of having an abnormal pregnancy outcome or an infant with minor malformations compared to healthy controls (odds ratio, with 95% confidence interval, respectively 2.1 (1.1, 4.0) and 2.0 (1.0, 4.0)). A significant correlation between the prevalence of abnormal pregnancy outcome and duration of epilepsy and AED treatment was found (risk increased by 9% (6%, 16%) per annum). No significant effect in terms of the type, the number or the serum level of the AEDs could be established. The head circumference of infants of epileptic mothers was significantly smaller (0.7 (1.2, 0.28 cm) compared to controls. An effect on the outcome of pregnancy of maternal folate supplementation or of folate blood concentrations during the periconceptional period and first trimester of pregnancy could not be determined. The severity of maternal epilepsy and/or AED treatment influences pregnancy outcome.