Pregnant women with epilepsy who are taking anti-epileptic drugs (AEDs) have an increased risk of pregnancy complications, caesarean section and major malformations of the newborn, finds new research published today in BJOG: An International Journal of Obstetrics and Gynaecology.

Epilepsy is a common neurological condition characterized by recurrent seizures. Previous studies have indicated that women taking AEDs are more likely to develop pre-eclampsia, gestational hypertension and have premature babies.

This latest study looked at 170 women with epilepsy who had a total of 205 deliveries between 1999 and 2006. The deliveries were divided into two groups according to the severity of the mother's epilepsy: those with epileptic seizures occurring less than five years before conceiving (known as active epilepsy) and those with seizures five years or more before conceiving (non-active epilepsy).

Among women with epilepsy, 57% were using AEDs. A control group of 205 women who did not have epilepsy was also part of the study.

The study found that women with epilepsy who use AEDs had an increased risk of preeclampsia, bleeding in pregnancy, induction, caesarean section and major malformations of the newborn.

Among women with epilepsy, 12.7% developed preeclampsia compared to 5.4% among the control group. Severe preeclampsia was also found to be more frequent in the epilepsy group (5.9% versus 1.5%) and women using AEDs were also more likely to develop preeclampsia compared to women with epilepsy not using them (7.8% versus 3.4%).

Induction of labour was performed in 21.0% of deliveries with epilepsy compared to 11.2% in the control group. Of the women using AEDs, 25% had to be induced compared to 15.7% of women not using them.

In addition, caesarean section was performed in 24.9% of deliveries with epilepsy compared to 12.7% of controls. Women using AEDs were twice as likely to have a caesarean section compared to those not using them (32.8% versus 14.6%).

Women with active epilepsy and no AED use had no increased risk of any pregnancy and delivery complications. However, there was an increased risk for vaginal forceps delivery and preterm birth in this group.

In women with epilepsy and using AEDs, 6.9% had major congenital malformations compared to 4.5% of women not using them.

Dr Ingrid Borthen, from the Department of Gynaecology and Obstetrics at Haukeland University Hospital, Bergen, Norway and co-author of the paper said:

"AEDs seem to play a role in the development of pregnancy and delivery complications. We do not know how this medication influences the pregnancy but we can suggest that the action of the medication has an impact on placentation.

"Further research is needed as both preeclampsia and bleeding are serious complications. Improved knowledge will aid clinicians to advise women with epilepsy about what medication is the safest to use for them and their baby."

Mike Marsh, Deputy Editor-in-Chief of BJOG said:

"This study indicates that women with epilepsy who take antiepileptic medications are at a slightly higher risk of preeclampsia, whereas those women with epilepsy who do not take antiepileptic medications are more likely to deliver their babies earlier. The reasons for these associations are as yet unclear.

"What is clear from this study is that pregnant women with epilepsy are a group of women who need specialist care during their pregnancy."

Reference

Borthen I, Eide M, Daltveit A, Gilhus N. Obstetric outcome in women with epilepsy: a hospital-based, retrospective study.
BJOG 2011; DOI: 10.1111/j.1471-0528.2011.03004.x.

Source:
Royal College of Obstetricians and Gynaecologists