Topamax May Raise Risk of Birth Defects
Small Study Shows Increase in Birth Defects When Epilepsy/Migraine Drug Is Used During Pregnancy
French tells WebMD that the study was too small to accurately assess the risk to babies born to mothers who take Topamax alone.
Kara Russell, a spokeswoman for Topamax manufacturer Ortho McNeill Neurologics, expressed similar concerns. "The sample sizes in this study were small, so more work needs to be done to really understand the results," she tells WebMD.
"We continue to support studies to provide clarity on the use of our drug in this population," she adds. "But it is really hard to reach a conclusion based on the small sample sizes in this study."
Three major databases currently track birth defects among babies born to women taking epilepsy drugs, but only one has so far provided information on Topamax, French says.
"We should know more soon when the other databases report on this drug," she says.
Like Shinnar, French emphasizes that for pregnant women with epilepsy, uncontrolled seizures have proven to be a much greater risk to the fetus than any epilepsy drug, including valproate.
The American Academy of Neurology recommends that women with epilepsy considering pregnancy take only one drug, if possible, to control seizures and that they take epilepsy drugs in the lowest effective dosages.
But discontinuing treatment during pregnancy can be very dangerous for a patient and her baby, she adds. During a mother's seizure and for the immediate period following the seizure, the level of oxygen being delivered to the placenta and fetus is low. This effect causes a drop in the infant's heart rate -- a sign of fetal distress. There are addition concerns of fetal and placental injury during the mother seizure which can lead to an increased risk of miscarriage.
"It's a double whammy," French says. "The baby has already been exposed and with withdrawal there is the added risk that a woman will suffer a seizure."