Obstetric trends show changes in complication rates and maternal characteristics such as caesarean section, induced labour, and maternal age. To what degree such general time trends and changing patterns of antiepileptic drug use influence pregnancies of women with epilepsy (WWE) is unknown. Our aim was to describe changes in maternal characteristics and obstetric complications in WWE over time, and to assess changes in complication risks in WWE relative to women without epilepsy.
This was a nationwide cohort study of all first births in the Medical Birth Registry of Norway, 1999–2016. We estimated maternal characteristics, complication rates, and risks for WWE compared to women without epilepsy. Main maternal outcome measures were hypertensive disorders, bleeding in pregnancy, induction of labour, caesarean section, postpartum hemorrhage, preterm birth, small for gestational age, and epidural analgesia. Time trends were analyzed by logistic regression and comparisons made with interaction analyses.
426 347 first births were analyzed, and 3077 (0.7%) women had epilepsy. In WWE there was an increase in proportions of induced labour (p<0.005) and use of epidural analgesia (p<0.005), and a reduction in mild preeclampsia (p = 0.006). However, the risk of these outcomes did not change over time. Only the risk of severe preeclampsia increased significantly over time relative to women without epilepsy (p = 0.006). In WWE, folic acid supplementation increased significantly over time (p<0.005), and there was a decrease in smoking during pregnancy (p<0.005), but these changes were less pronounced than for women without epilepsy (p<0.005).
During 1999–2016 there were important changes in maternal characteristics and complication rates among WWE. However, outcome risks for WWE relative to women without epilepsy did not change despite changes in antiepileptic drug use patterns. The relative risk of severe preeclampsia increased in women with epilepsy.
Epilepsy is one of the most common chronic diseases during pregnancy.[1–4] Women with epilepsy (WWE) have been considered as high risk parturients with increased risk for maternal complications.[2–8] Almost half of women with ongoing or previous epilepsy use antiepileptic drugs (AEDs) in pregnancy to control seizures despite their potential adverse effects on the fetus and maternal complications.[2, 9–11] The pattern of antiepileptic drug use in pregnant WWE has changed markedly during the last two decades owing to newer antiepileptic drugs, primarily lamotrigine and levetiracetam, replacing older antiepileptic drugs, such as carbamazepine, phenytoin, and valproate. [12–14] The newer antiepileptic drugs are better tolerated and believed to have less fetal and maternal adverse effects, but are associated with increased seizure risk during pregnancy.[10, 11, 15–19] Increasing maternal age, increasing maternal body mass index (BMI), and decrease in smoking during pregnancy over the last two decades should also affect WWE.[20–23] These factors could be proportional or have a more complex interaction. Global trends show an increase in caesarean section rates and increased induction of labour.[24–26] Such interventions are common in WWE.[2, 4, 5, 7, 8] During the last decade, there has been an increasing focus on management of WWE during pregnancy and delivery and recent guidelines encourage close monitoring of pregnancies in WWE and strict indications for interventions.[25, 27–30] However, there is little data on how focused management and guidelines have affected maternal outcomes of WWE. A recent meta-analysis indicates a trend towards increasing rates of caesarean section and induction of labour in WWE. However, different geographical populations with great variation in obstetric practice were compared to describe differences over time, and no reference populations were included. Therefore, it is not known how changes in population characteristics, obstetric practice and general complication rates have affected WWE. We expect that changes during the recent years in folate use, indications for operative interventions, and AEDs used have all influenced maternal complications in WWE during pregnancy and when giving birth.
By analyzing a stable nationwide cohort over 18 years, our aim was to describe changes in maternal characteristics and maternal complication rates in WWE over time, and to assess changes in complication risks relative to women without epilepsy. For changes in outcome risks in WWE over time, the influence of AED use and other specific factors were assessed.