The outcome of altering antiepileptic drug therapy before pregnancy.

We investigated the outcome of altering antiepileptic drug (AED) therapy in the year before pregnancy on 2233 occasions in Australian women in the 20-year period of functioning of the Raoul Wallenberg Australian Pregnancy Register (APR). Therapy had been altered in 358 instances (16%) in the months prior to the pregnancy (median interval: 18 weeks). Antiepileptic drug doses had been changed in 141 pregnancies (39.4%), being decreased in 94; drugs changed in 151 (42.2%); drugs withdrawn without replacement in 66 (18.4%) but resumed in 40 before pregnancy ended. The main drugs involved were valproate (34%), phenytoin (16.5%), topiramate (12.6%), and carbamazepine (11.4%). Antiepileptic drug doses were increased significantly more often (16.9% vs. 6.4%) when epilepsy before pregnancy was not controlled, and AED treatment ceased significantly less often (13.6% vs. 24.0%). The alterations were more often made in women with generalized epilepsies and in those whose seizure disorders were not fully controlled in the prepregnancy year, suggesting that avoidance of teratogenicity and achieving improved seizure control often motivated the changes. Overall, the alterations did not result in improved rates of seizure freedom during pregnancy, as compared with pregnancies where therapy was unchanged; however, fetal malformation rates were lower 3.6% vs. 5.4%, but this difference did not attain statistical significance. The same trends regarding seizure control and malformations persisted after pregnancies involving valproate exposure were excluded. In conclusion, this analysis of the APR cohort did not demonstrate that altering AEDs before pregnancy produced a significant improvement in seizure control and the reduction in fetal malformation rate that occurred was not statistically significant.

Preexisting illness, fetal malformation, and seizure control rates in pregnant women with epilepsy.

Data from 2182 pregnancies in the Australian Register of antiepileptic drugs in pregnancy that were followed to term, with 1965 followed for another year, were analyzed to ascertain whether preexisting illness influenced i. the hazard of fetal malformations, and ii. seizure control during pregnancy. Fetal malformation occurred in 74 of the 842 pregnancies associated with preexisting illness (8.8%) and in 84 of the 1340 comparator pregnancies (6.27%), Relative Risk (R.R.) = 1.402 (95% Confidence Interval (C.I.) = 1.038, 1.893). Logistic regression showed statistically significant effects of preexisting maternal drug-treated psychiatric illness, untreated psychiatric illness, and use of citalopram, carbamazepine, valproate, and topiramate in increasing hazard of fetal malformation. Preexisting nonpsychiatric illness and other antiepileptic drugs and drugs prescribed for psychiatric illness, mainly antidepressants, had no such effect. Seizures occurred during 405 of the 842 pregnancies associated with preexisting illness, and during 593 of 1340 comparison pregnancies (48.1% v 44.3%; R.R. = 1.087; 95% C.I. = 0.991, 1.192). There were no statistically significant relationships between preexisting nonpsychiatric and psychiatric illnesses separately and seizure control during pregnancy. Thus, apart from consequences of antiepileptic drug exposure, preexisting maternal psychiatric illness, in its own right, or when treated with citalopram, appears to be associated with increased hazards of fetal malformation.

Cesarean section in Australian women with epilepsy.

The literature suggests that cesarean delivery or birth is carried out more often in pregnant women with epilepsy (WWE) than in pregnant women in the general population. Data were utilized from the Australian Pregnancy Register (APR) for Women on Antiepileptic Medication to investigate this issue in Australia. Over almost two decades, the mean CS rate in 1900 APR women was 39.2%, but was only 29.9% in women in the general population (relative risk (R.R.) = 1.31, 95% confidence interval (C.I.) 1.24, 1.39). Rates for forceps and suction-assisted delivery were similar in the two datasets. The 9.3% excess CS rate was almost entirely accounted for by operations carried out prior to the onset of labor. The rates for CS during labor were very similar. Only 11.0% of the WWE knew the indication for their prelabor CS, whereas 69.8% knew why theirs had been carried out during labor (odds ratio (O.R.) = 0.054; 99% C.I. 0.032, 0.089). Slightly older mothers and increased proportions of primipara probably made small contributions to the increased prelabor CS rate in the Australian WWE, but most of the excess could not be accounted for in the Register data. Australian obstetricians may have tended to regard prelabor CS as a preferable course of action in managing delivery in WWE, even in the absence of other indications.