Pregnant women taking antiepileptic drugs have higher odds for preeclampsia, bleeding, labor induction, caesarean section, and major malformations of the newborn, Norwegian researchers have learned.
The findings add to mounting evidence that pregnancy risks for epileptic women may be linked to antiepileptic drugs (AEDs) rather than epilepsy itself.
Dr. Ingrid Borthen of Haukeland University Hospital, in Bergen, Norway, and her associates retrospectively compared obstetric outcomes for 205 deliveries by 170 women with a past or present history of epilepsy (57% of whom were taking AEDs) and 205 matched, nonepileptic control patients.
The women in both groups had a mean age of 28 years.
Epileptic women taking AEDs had higher odds of severe preeclampsia (odds ratio, 5.0; 95% confidence interval, 1.3–19.9), bleeding in early pregnancy (OR, 6.4; 95% CI, 2.7–15.2), labor induction (OR, 2.3; 95% CI, 1.2–4.3), c-section (OR, 2.5; 95% CI, 1.4–4.7), and malformations in the offspring (OR, 7.1; 95% CI, 1.4–36.6).
The comparisons of outcomes between the two groups were controlled for confounding factors, including smoking during pregnancy, mother's age, highest maternal education, parity, body mass index of 30 kg/m
Women with active epilepsy (defined as seizures within 5 years of conception) not using the drugs did not have increased odds for any of these outcomes; however, they did have higher odds for vaginal forceps delivery and preterm birth.
Which specific drugs may be implicated is still difficult to say, said Dr. Borthen, but the study showed that lamotrigine is associated with a higher risk (BJOG 2011 [doi:10.1111/j.1471-0528.2011. 03004.x]).
Dr. Borthen and her colleagues noted that the proportion of women using AEDs during pregnancy may represent a larger group than epileptic women, as there is “growing use of AEDs for pain and psychiatric conditions.”
One limitation of the study, Dr. Borthen and her colleagues wrote in their analysis, was a lack of data on seizure type and severity.
The study was funded by the Norwegian Research Council. Dr. Borthen and her colleagues declared that they had no conflicts of interest.