New Tool Predicts Epileptic Seizure Risk During Pregnancy
Impact of Epilepsy on Women of Childbearing Age
In the United States, more than 1 million women of childbearing age are affected by epilepsy. Antiepileptic drugs, while crucial for managing seizures, are linked to potential risks such as congenital malformations, growth retardation, and neurocognitive development defects in infants. This creates a challenging dilemma for women considering whether to continue their medication during pregnancy, often leading to discontinuation without consulting a healthcare professional.
Increased Mortality Risk in Pregnant Women with Epilepsy
Women with epilepsy face a significantly heightened risk of mortality if they cease taking antiepileptic medications without medical advice, resulting in a ten-fold increase in the risk of death from seizures.
Objectives of Seizure Management in Pregnancy
The primary goal of managing seizures during pregnancy is to ensure effective seizure control while minimizing fetal exposure to antiepileptic drugs. Achieving this balance is essential to reduce the likelihood of structural abnormalities and neurodevelopmental issues in the fetus, as well as to mitigate the risks associated with seizure-related trauma.
Physiological Changes and Seizure Frequency
Pregnancy introduces various physiological, psychological, and hormonal changes that can influence the frequency of seizures. These changes also affect the efficacy of antiepileptic medications during this period.
Introduction of the EMPiRE Risk Calculator
Researchers from Queen Mary University of London have developed a new risk calculator known as EMPiRE (ANtiEpileptic drug Monitoring in PREgnancy). This tool can accurately forecast the risk of seizures during pregnancy and up to six weeks postpartum. The findings were published in PLOS Medicine, following a study conducted across 50 hospitals in the U.K., involving 527 pregnant women with epilepsy.
Study Design and Findings
The participants were classified into two datasets. The model development dataset included 399 women whose antiepileptic drug dosages were adjusted based solely on clinical features, while the validation dataset consisted of 128 women whose dosage adjustments were informed by serum drug levels. Monthly serum levels of antiepileptic drugs were monitored, and women documented their seizure activity in diaries throughout the study, which extended to six weeks after delivery.
The results revealed that seizures occurred in 46% of women in the model development group and 45% in the validation group. Eight significant predictors of seizure occurrence were identified: age at first seizure, history of mental health disorders, seizure classification, previous hospital admissions due to seizures, and recent seizure activity prior to pregnancy.
Effectiveness of the EMPiRE Model
The EMPiRE model demonstrated strong predictive capabilities for seizure risk at the time of antenatal booking for pregnant women with epilepsy on antiepileptic medication. Freely accessible online, this model serves as a valuable resource for general practitioners, epilepsy specialists, obstetricians, and midwives, facilitating the identification of high-risk patients and the need for close monitoring during pregnancy, labor, and postpartum.
Potential Impact on Maternal and Infant Health
This predictive tool has the potential to empower women with epilepsy, enabling them to make informed decisions regarding pregnancy and antiepileptic treatment. The risk estimates provided can guide tailored treatment strategies, ultimately aiming to protect the lives of both mothers and infants.
Limitations and Future Research Directions
While the EMPiRE model is clinically relevant and effective in estimating seizure risk, several limitations must be acknowledged. Its applicability is primarily to high-income countries, the validation sample had a limited number of events, and it does not identify women with a risk below 12%. The authors recommend further studies to assess the model’s acceptability among women with epilepsy and their healthcare providers.
Conclusion: Tailoring Treatment with EMPiRE
The study concludes that the EMPiRE tool offers a straightforward means of calculating individualized seizure risk for women on antiepileptic drugs during pregnancy. These risk estimates can significantly influence monitoring intensity, patient care strategies, and medication adjustments, ultimately empowering pregnant women with epilepsy to make informed choices that minimize seizure risks.
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.