Researchers have developed a tool that can accurately predict the risk of epileptic seizures in pregnancy.
In the United States, over 1 million women of childbearing age have epilepsy. Antiepileptic drugs are known to be associated with congenital malformations, growth retardation, and neurocognitive development deficit. The dilemma to use or not to use antiepileptic drugs during pregnancy may cause women to stop using their medication without consulting their physicians. These issues present unique challenges in the treatment and management of epileptic seizures in pregnancy.
Women with epilepsy are at increased risk of death
Since many women discontinue the use of antiepileptic drugs during pregnancy without their specialist’s advice, they have a ten-fold increased risk of death due to seizures.
The goal of treatment for seizures in pregnancy
The goal of treatment for seizures in pregnancy is to achieve optimal seizure control while minimizing exposure of the fetus to antiepileptic drugs. This balance can help reduce the risk of structural and neurodevelopmental abnormalities of the fetus as well as reduce the risk of trauma associated with seizures.
New studies in this field have provided important insights that can help predict seizures in pregnancy and regulate the use of antiepileptic drugs.
Frequency of seizures in pregnancy
There are a number of physiological, psychological, and hormonal changes in pregnancy that may be associated with the frequency of seizures in pregnancy. These changes also contribute to alterations in the effect of antiepileptic drugs taken during pregnancy.
New risk calculator of epileptic seizures in pregnancy
Researchers from Queen Mary University of London recently developed a new risk calculator EMPiRE (ANtiEpileptic drug Monitoring in PREgnancy) that can accurately predict the risk of seizures in pregnancy and up to six weeks after delivery. The study was recently published in PLOS Medicine. The EMPiRE cohort study was conducted in 50 hospitals in the U.K. and included data for 527 pregnant women with epilepsy who were on antiepileptic drugs. The patients were divided into two datasets. The model development dataset included 399 women whose antiepileptic drug doses were adjusted based on clinical features only. The validation dataset included 128 women whose drug dose adjustments were informed by serum drug levels. The researchers assessed serum levels of antiepilepsy drugs every month. Women recorded their convulsive and non-convulsive seizures in seizure diaries and were followed until six weeks after delivery.
The study found that seizures occurred in 46% of women in the model development dataset and 45% of women in the validation dataset. The researchers found eight predictors that were significantly associated with the occurrence of seizures, these were: age at first seizure, history of mental health disorder, seizure classification, hospital admission due to seizures in previous pregnancy, convulsive seizure in three months before pregnancy, non-convulsive seizure in three months before pregnancy, and baseline dose of antiepileptic drugs.
The EMPiRE model performed well in predicting the risk of seizures in pregnancy
Using the routinely available characteristics that are easy to measure, the EMPiRE model performed well in predicting the risk of seizures at the time of antenatal booking in pregnant women with epilepsy who were taking antiepileptic medication.
The model, freely available online, can be used as an important tool by general practitioners, epilepsy specialists, obstetricians, and midwives to identify high-risk women and determine the need for close monitoring in pregnancy, labor, and after birth. It can also help in assessing antiepilepsy drug management.
The model can save maternal and infant lives
The model can empower women with epilepsy and help them make informed decisions about getting pregnant and their antiepileptic treatment during pregnancy. The risk estimates can help guide individualized treatment for the patients and help save the lives of mothers and babies.
These findings should be interpreted with caution
Although the model is clinically relevant and it performed well in estimating the risk of seizures in pregnancy, there are certain limitations that must be kept in mind. The model is mainly applicable to high-income countries, it included a small number of events in the validation sample, and the model was not able to identify women below 12% risk.
The authors suggest that future studies are needed to assess the acceptability of this model to women with epilepsy and their healthcare providers.
EMPiRE can guide individually tailored treatment
The study concludes that EMPiRE is a simple prediction tool that can calculate the individualized risk of seizures in pregnancy for women on antiepilepsy drugs. These estimates can help tailor the choices made by patients and their healthcare providers. The model can influence the intensity of monitoring during pregnancy and after delivery, patient care strategies, and antiepilepsy drug dose adjustments. The researchers are optimistic that his tool can empower pregnant women with epilepsy to make informed decisions about what is right for them to minimize the risk of seizures in pregnancy.
Written by Preeti Paul, MS Biochemistry
Reference: Allotey J, Fernandez-Felix BM, Zamora J, Moss N, Bagary M, Kelso A, et al. (2019) Predicting seizures in pregnant women with epilepsy: Development and external validation of a prognostic model. PLoS Med 16(5):e1002802.