It’s been nearly 20 years since the North American Antiepileptic Drug (AED) Pregnancy Registry has been gathering data to answer the important question – “Is my AED safe to take during pregnancy?” We can tell you that 3 AEDs may be far from safe:
Phenobarbital, which has been available since 1912, was the first drug our team studied. Since it had been on the market for quite a while, most of the pregnant women who initially signed up for our Registry were taking this drug. This provided our researchers with a large enough sample to conclude that there was a direct correlation between taking phenobarbital and a greater risk of having a baby with heart and/or cleft lip/palate defects. Fortunately, the drug companies were not advertising the drug very aggressively (since it was so cheap) and the registry saw a decline in the number of women using this drug.
Valproic Acid is another drug the Registry identified as increasing the chances for birth defects if taken while pregnant. Numerous defects were observed in babies born to women taking it, including defects in the heart, kidney, fingers and toes. Affected babies also had distinct facial features. Heart, cleft lip/palate birth defects, as well as spina bifida, can also be attributed to taking Valproic Acid.
A third drug that is still being studied but has shown signs of increasing the risk of birth defects is Topiramate (Topamax®). The registry is hoping to enroll more women taking this drug so that they can provide more solid evidence. So far, the data is showing the risk rate for having a child with certain birth defects doubles when the mother is taking this drug.
“Fortunately, there are AEDs that have been developed within the last 12 years that show promise of being safe, which means they are improving,” said Lewis B. Holmes, MD, Director of the North American AED Pregnancy Registry and Professor of Pediatrics at Harvard Medical School. For example, Dr. Holmes says lamotrigine and levetiracetam show positive signs of carrying less risk of causing problems in the baby if taken during pregnancy. However, the only way to be sure any drug is safe to take when pregnant, is to continue to enroll not only pregnant women taking AEDs but also women who are pregnant but not taking AEDs, according to Dr. Holmes. They’re known as “controls.” “The North American AED pregnancy registry is the first registry of its kind to have an internal control group specifically recruited for this registry. This gives the registry a strength nobody else has.”