Chapter 16 Management of Epilepsy and Pregnancy. Epilepsy in Women - The Scientific Basis for Clinical Management. Elsevier; 2008. pp. 273-82. [DOI: 10.1016/s0074-7742(08)00016-0]

External validation of the AntiEpileptic Drug Monitoring in PREgnancy (EMPiRE) model for predicting seizures in pregnant women with epilepsy

BACKGROUND

The AntiEpileptic Drug Monitoring in PREgnancy (EMPiRE) model is the only available tool for predicting seizures in pregnant women with epilepsy (WWE) using anti-seizure medications (ASMs); however, its predictive performance requires validation. This study aimed to evaluate the predictive ability of this model in pregnant Chinese WWE and its potential usefulness in clinical practice.

METHODS

Data of the EMPiRE model were derived from the EMPiRE study, a prospective multicenter cohort study that recruited women on ASM monotherapy (lamotrigine, carbamazepine, phenytoin or levetiracetam) or polytherapy (lamotrigine with either carbamazepine, phenytoin or levetiracetam). Based on the applicable population of the EMPiRE model, we evaluated 280 patients registered in the Wenzhou Epilepsy Follow-up Registry Database from January 1, 2010, to December 31, 2020. A total of 158 eligible patients were included in the validation cohort. We collected data on the baseline characteristics of patients, eight predictors of the EMPiRE model and outcome events. The outcome was the occurrence of tonic-clonic or non-tonic-clonic seizures at any time in pregnancy up to 6 weeks postpartum. We used the equation of the EMPiRE model to obtain the predicted probabilities of seizures. The predictive ability of the EMPiRE model was quantified by the C-statistic (scale 0-1, values > 0.5 show discrimination), GiViTI calibration test and decision curve analysis (DCA).

RESULTS

Of 158 eligible patients, 96 patients (60.8%, 96/158) experienced one or more seizures at any time between pregnancy and 6 weeks postpartum. The EMPiRE model showed good discrimination with a C-statistic of 0.76 (95% confidence interval [CI] 0.70-0.84). The GiViTI calibration belt showed that the predicted probabilities, which ranged from 16 to 96% (95% CI), were lower than the actual probabilities. DCA indicated that the highest net proportional benefit was obtained for predicted probability thresholds of 15-18% and 54-96%.

CONCLUSIONS

The EMPiRE model could discriminate well between WWE with and without seizures during pregnancy and 6 weeks postpartum, but the risk of seizures may be underestimated. The limitations of the model for specific medication regimens may limit its real-world application. If the model is further improved, it will be incredibly valuable.

New-onset epilepsy in pregnant women: clinical features and delivery outcomes

INTRODUCTION

Most seizures during pregnancy occur in women who already have epilepsy. Rarely, some women may have their first seizure during pregnancy. The purpose of this study was to investigate the clinical features and pregnancy outcomes in women with new-onset epilepsy during pregnancy.

METHODS

112 pregnant women with epilepsy were prospectively evaluated at the Education - Therapeutic Clinic of the Azerbaijan Medical University, in the neurological and maternity departments of the Clinical Medical Center in Baku over a six-year period. Women were regularly followed by a neurologist and obstetrician till the end of pregnancy. To determine the recurrence of seizures during the pregnancy and after delivery, the women were followed up at least once per three months for a one year period after delivery. Delivery and perinatal outcomes were compared with those of 277 healthy women in the control group (without epilepsy and without registering chronic diseases).

RESULTS

Of the 112 pregnant women with epilepsy, 12 (10.7%) had their first seizures during the pregnancy: 6 in the 1^st, 4 in the 2^nd, 2 in the 3^rd trimester. Women with new-onset epilepsy had increased risk of cesarean section and perinatal hypoxia in offspring, compared with controls (Odds ratio [OR]: 13.57; 95% confidence interval (CI):2.86-64.31 and OR: 3.61; 95 % CI: 1.06-12.27, respectively). The risks of cesarean section and perinatal hypoxia were not increased in women with new-onset epilepsy compared to women with epilepsy before pregnancy (OR 2.64; 95 % CI 0.54-12.93 and OR 2.18, 95% CI 0.61-7.76, respectively).

CONCLUSION

In our cohort, women with new-onset epilepsy may have an increased risk of delivery by cesarean section and perinatal hypoxia compared to pregnant controls. The risks were not increased compared to women with epilepsy before pregnancy. Neonatal hypoxia was associated with delivery by cesarean section.

Managing epilepsy during pregnancy: assessing risk and optimizing care

OPINION STATEMENT

Epilepsy is the most common neurologic condition found in pregnancy. As such, all neurologists, internists, and obstetricians should know how to counsel women with epilepsy as they are considering pregnancy. While all of the usual recommendations for women of childbearing potential apply, including preconceptual and ongoing use of folic acid, calcium, and vitamin D, additional consideration must be given to the need for adjustment or change of anticonvulsant therapy. Monotherapy with the lowest dose of medication needed to control seizures should be prescribed prior to conception. Most anticonvulsants have a favorable profile when used in pregnancy; older anticonvulsants such as valproate and carbamazepine should be avoided, as they are associated with higher rates of fetal malformation, and in the case of valproate, with proven cognitive deficits in children exposed to this medication in utero. With use of any anticonvulsant medication, dosing throughout pregnancy will need to be adjusted to maintain an appropriate serum concentration. Dosing of anticonvulsants needs to be decreased after delivery to avoid medication-related toxicity, although sleep deprivation and hormonal fluctuation can increase the risk of seizures in postpartum women. With proper management, the majority of women with epilepsy can have uneventful pregnancies and healthy babies.

The management of epilepsy in pregnancy

While most women with epilepsy can expect a normal pregnancy outcome, epilepsy remains a significant contributor to both maternal and perinatal morbidity. Pre-pregnancy planning must address reliable contraception and optimisation of antiepileptic drug (AED) regimens to minimise teratogenic risk while maintaining seizure control. The most recent data from the AED registries regarding malformations is presented in this review, as is the limited data on the newer AEDs and studies linking neurocognitive outcomes to AED exposure. During pregnancy, important considerations include; therapeutic drug monitoring, surveillance for obstetric complications and vigilance for seizures during the intrapartum and postpartum period.