The effect of parity on risk of complications in pregnant women with epilepsy: a population-based cohort study.

INTRODUCTION: Women with epilepsy have increased risk of complications in pregnancy with consequences for the mother and child. There are no studies on the influence of parity on complications in women with epilepsy. MATERIAL AND METHODS: This was a population-based cohort study of all first and second births in the Medical Birth Registry of Norway 1999-2013. Risks were estimated and complication rates were compared in distinct women with epilepsy treatment categories. Outcomes were any hypertensive disorder, bleeding in pregnancy, induction of labor, cesarean section, postpartum hemorrhage and preterm birth.

RESULTS: We examined 361 588 women, of whom 211 248 had a second birth and 1074 (0.5%) of these had a diagnosis of epilepsy in both births. Of these, 406 used antiepileptic drugs in both pregnancies with lamotrigine (n = 118), carbamazepine (n = 83), valproate (n = 44) and levetiracetam (n = 27) being the four most common monotherapies. In the second birth, only risk of elective cesarean section (adjusted odds ratio 1.7, 95% confidence interval 1.4-2.0) and induction of labor (adjusted odds ratio 1.5, 95% confidence interval 1.2-1.7) were increased in women with epilepsy compared with women without epilepsy. There was a significant reduction in any hypertensive disorder, mild preeclampsia, emergency cesarean section, postpartum hemorrhage (>500 mL) and preterm birth from first to second birth in women with epilepsy, and also a significant increase in elective cesarean section.

CONCLUSIONS: Second births in women with epilepsy do not represent an increased risk of non-iatrogenic complications, independent of antiepileptic drug use. There is a significant reduction in complications from first to second births in women with epilepsy.