Dec 21, 2000 (Reuters)
Certain epilepsy drugs may be behind developmental delays in some children whose mothers took the medications while they were pregnant, results of a UK study suggest. However, experts warn the findings should be interpreted with caution since most women with epilepsy have healthy babies, and stopping drug treatment can be put a woman's health and her pregnancy at risk. In a survey of 721 women with epilepsy, investigators found that children who were exposed to any epilepsy drug in the womb were 50% more likely than unexposed children to have special educational needs. Much of the risk was attributed to the drug valproate. Women on that drug alone were more than three times as likely as women on no drugs to have a child with developmental delays. Those who took valproate in combination with other drugs had a 2.5-times greater risk. Drug combinations that did not include valproate were linked to a 50% increase in risk, while another common epilepsy drug, carbamazepine, was not associated with developmental delays. Dr. David Chadwick and his colleagues at the Walton Centre for Neurology and Neurosurgery in Liverpool report the findings in the January issue of the Journal of Neurology, Neurosurgery and Psychiatry. Epilepsy is a brain disorder in which nerve cells are sometimes abnormally activated, often triggering seizures. Although certain anti-seizure medications are known to increase the risk of birth defects when taken during pregnancy, uncontrolled seizures also present a risk. So women who normally need the drugs continue to take them during pregnancy. In an interview with Reuters Health, Dr. Martha Morrell of Columbia University in New York City said that an ongoing concern has been whether epilepsy drugs could have lasting effects on children's central nervous systems. "We've needed studies in this area very badly," she said.
While Morrell called the new findings "very concerning," she cautioned that the study had several limitations. For example, she noted, the women who were on drugs must have had more severe epilepsy than those not on drugs, which could affect their children's risk of developmental problems. And, she said, the researchers were unable to look at genetic factors that could have affected the children's development. Because different drugs are given for different types of epilepsy, it may not be possible or desirable to simply take a pregnant woman off valproate. But, according to Morrell, doctors should strive to expose a fetus to as little of any drug as possible. "We really want to use only one medication whenever possible and at the lowest dose possible," she said. Chadwick's team did not look at drug doses. These findings, they write, should be "interpreted with caution," but should also spur "urgent investigation to clarify and optimise treatment for women with epilepsy who are of childbearing age." Morrell added that a multi-center study under way in the US will follow women on epilepsy drugs through pregnancy and continue to monitor their children's development until age 5.
SOURCE: Journal of Neurology, Neurosurgery and Psychiatry 2001;70:15-21.
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