Pregnancies of Women with Epilepsy: A Population‐Based Study in Iceland

Abstract

Summary:Purpose: Women with epilepsy who become pregnant are commonly considered to be at high risk for complications during pregnancy or delivery. The offspring are also considered to have increased risk of perinatal mortality, congenital malformations, and maturational delay. Because few of these studies are population based, potential bias exists because of selection.Methods: We performed a historical population-based cohort study in Iceland to determine the prevalence of epilepsy among pregnant women, to identify pregnancy and delivery complications in women with epilepsy, and to determine the outcome of their pregnancies as compared with that in the general population of Iceland. We identified all women with active epilepsy who gave birth during a 19-year period in Iceland.Results: In this population, 3.3 in 1,000 pregnancies involve mothers with active epilepsy. The frequency of adverse events (AE) during pregnancy in the women with epilepsy is similar to that observed among all live births in the population, but cesarean section was performed twice as frequently as in the general population. Perinatal mortality rate and mean birth weight are not significantly different in the offspring of women with epilepsy as compared with rest of the population. The risk of major congenital malformations (MGM) is increased 2.7-fold over that expected when a mother is treated with antiepileptic drugs (AEDs) during a pregnancy.Conclusions: Our study indicates that the rate of complications of pregnancy in mothers with active epilepsy is low and similar to that of the general population with epilepsy. Use of AEDs by the mother during pregnancy significantly increases the risk of MGM in the offspring. Key Words: Epidemiology-Epilepsy-Pregnancy-Congenital malformations-Iceland.Women with epilepsy who become pregnant are frequently considered to have a high risk of an adverse outcome (1,2). Numerous studies also indicate an increased risk of malformations (3,4) in offspring of mothers with epilepsy. Few population studies have determined the proportion of all pregnancies that occur in women with active epilepsy. We performed a population-based survey in Iceland to identify all women with epilepsy who gave birth during the 19-year period from 1972 through 1990. We wished to determine the proportion of pregnancies in women with active epilepsy among all pregnancies and to compare the proportion with complications of pregnancy, delivery, and outcome in those with and without epilepsy. PATIENTS AND METHODSIndex cases were all women with epilepsy treated with antiepileptic drugs (AEDs) during pregnancy or during a 5-year period preceding the pregnancy. All the women were residents of Iceland and gave birth in Iceland during the study period. Only live births, products of pregnancies progressing at least through week 28 of gestation were included. The study period was from January 1, 1972 to December 31, 1990.Index cases were identified from records of all the hospitals in the country where children are born. Supplemental inform...

Management issues for women with epilepsy—Focus on pregnancy (an evidence‐based review): I. Obstetrical complications and change in seizure frequency

“…A Class III study (Hiilesmaa et al, 1985) showed no significant increased risk but was not sufficiently sensitive to exclude an increased risk (RR 0.7, 95% CI 0.3-1.4). In a categorical, chi-square statistic, it was reported that the rates of premature births were not different than controls (p = 0.3) (Olafsson et al, 1998), and another study found no differences in gestational ages in the offspring of WWE compared to controls [WWE = 38.06, standard deviation (SD) 1.42 vs. controls = 38.17, SD 3.58 weeks] (Sawhney et al, 1996).…”

“…Three Class III studies [OR 17.88, 95% CI 4.73-67.58 (Laskowska et al, 2001); OR 1.58, 95% CI 1.10-2.25 (Olafsson et al, 1998); and OR 2.2, 95% CI 1.42-3.41 (Sawhney et al, 1996) ] demonstrated a significant substantial increased risk.…”

“…A Class II study (Richmond et al, 2004) did not show a significant increased risk of cesarean delivery in WWE compared to women without epilepsy (OR 1.24, 95% CI 0.99-1.55). However, both studies were insufficiently sensitive to exclude a moderately increased risk.Three Class III studies [OR 17.88, 95% CI 4.73-67.58 (Laskowska et al, 2001); OR 1.58, 95% CI 1.10-2.25 (Olafsson et al, 1998); and OR 2.2, 95% CI 1.42-3.41 (Sawhney et al, 1996) ] demonstrated a significant substantial increased risk.Other than the increased risk of bias and statistical imprecision of some studies, there is little information to explain the increased cesarean delivery rate observed in the Class III studies compared to the Class I and II studies.Conclusion Based on evidence from one Class I and one Class II study, it is probable that WWE taking AEDs do not have a substantially increased risk of cesarean delivery. Because of the lack of statistical precision in the Class I and Class II studies and the evidence from multiple Class III studies, a moderately increased risk of cesarean delivery is possible.…”

“…A Class III study (Hiilesmaa et al, 1985) showed no significant increased risk but was not sufficiently sensitive to exclude an increased risk (RR 0.7, 95% CI 0.3-1.4). In a categorical, chi-square statistic, it was reported that the rates of premature births were not different than controls (p = 0.3) (Olafsson et al, 1998), and another study found no differences in gestational ages in the offspring of WWE compared to controls [WWE = 38.06, standard deviation (SD) 1.42 vs. controls = 38.17, SD 3.58 weeks] (Sawhney et al, 1996).Conclusions Based on evidence from one Class I study, it is probable that WWE taking AEDs do not have a moderately increased risk of premature contractions and premature labor and delivery during pregnancy. However, based on evidence from one Class II study, it is possible that WWE who smoke do have a substantially increased risk of premature contractions and premature labor and delivery during pregnancy compared to women without epilepsy who smoke.…”

Management of Epilepsy and Pregnancy

“…Frequency of cesarean section may be increased for WWE, although most of them can have normal vaginal delivery. [28] Uterine inertia, seizures, and failure of progression of labor are usual causes of cesarian section (Table 2). [29] A generalized seizure at term can cause transient fetal asphyxia, as evidenced by cardiotocography.…”