May 6, 2002
Researchers find that pregnant women with untreated epilepsy are not at an increased risk of having an infant born with a birth defect
Researchers at Toronto's Hospital for Sick Children (SickKids) have concluded that there is no evidence of an increased chance of major birth defects occurring in the offspring of women with epilepsy who do not take anti-epileptic medications during pregnancy.
The Motherisk study, presented at the Pediatric Academic Societies Annual Meeting in Baltimore, Maryland, conducted a meta-analysis of published studies reporting pregnancy outcome among women of untreated epilepsy compared with healthy controls. It is widely believed that women with epilepsy have higher than standard risk for giving birth to a child with malformations, independent of the effects of anti-epileptic drugs (AEDs). This research sought to determine through a systematic review of studies on the subject the reality behind this perception.
Ten papers, six cohort studies and four case-controlled studies met the inclusion criteria and were included in the meta-analysis. The risk for congenital malformations in offspring of women with untreated epilepsy was found to be not significantly higher than in healthy controls. In contrast, the offspring of women treated with anti-epileptic drugs had higher incidence of major malformations than healthy controls.
"The association of fetal malformations with untreated maternal epilepsy is controversial. From this research we found no evidence of increased risk for major malformations in offspring of women who did not take anti-epileptic medications during gestation," said Dr. Irena Nulman, co-author and presenter of the study at the Pediatric Academic Societies Annual Meeting.
"This information is reassuring for women with epilepsy who do not need to take AEDs. It is also important for women with specific types of epilepsy and their physicians, who may choose to discontinue AEDs during the first trimester in order to reduce risks of major malformations," said Dr. Gideon Koren, the study's principal investigator, director of the Motherisk Program at SickKids, and a professor of Paediatrics, Pharmacology, and Medicine and Medical Genetics at the University of Toronto.
The teratogenic risk associated with AEDs appears to be four to eight per cent, roughly two to three times greater than the general obstetric population. Presently, there is no consensus regarding which anticonvulsant drug is the safest for the pregnant mother's unborn child.
This research is supported by The Hospital for Sick Children Foundation and the Research Leadership in Better Pharmacotherapy during Pregnancy and Lactation.
The Hospital for Sick Children, affiliated with the University of Toronto, is the largest paediatric academic health science centre in Canada and one of the largest in the world. Its mission is to provide the best in family-centred, compassionate care, to lead in scientific and clinical advancement, and to prepare the next generation of leaders in child health.
For more information, please visit www.sickkids.ca. Motherisk is a consultation service for pregnant or lactating women and their health care providers concerning the fetal risks associated with drug, chemical, infection, disease and radiation exposure during pregnancy. For more information, please visit www.motherisk.org.
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