Pregnancy Registries Enrolling Thousands to Determine Drug Effects on Infants

By between Us Staff
Posted: April 13, 2004

Thousands of pregnant women with epilepsy are signing up with pregnancy registries in an effort to determine which antiepileptic drugs are safest during pregnancy, and which carry the greatest risk to the developing child.

"It is a selfless commitment to the well-being of other women and their babies, and it is happening worldwide," said Eric Hargis, president and CEO of the Epilepsy Foundation.

Although more than 90 percent of women with epilepsy who become pregnant deliver normal, healthy babies, as a group their risk of having a child with a defect is about twice the risk that all women face (4–6 percent vs. 2–3 percent). Still, little is known about how much risk is posed by individual drugs.

Currently, more than 12,500 women have been or are now enrolled in pregnancy registries in the United States and overseas. A few articles have been published that indicate elevated risks appear for two widely used medications, phenobarbital and valproate. Experts, however, maintain there is still not enough scientific data to show conclusively which medicines carry less or more risk to the baby.

In an effort to encourage greater and quicker release of registry findings, the Epilepsy Foundation recently sponsored a meeting of representatives of five of the largest registries, together with experts in epilepsy treatment and epidemiology, and representatives of the voluntary sector.

The meeting took place in New York, March 1 and 2, and was chaired by Gregory L. Barkley, M.D., medical director of the Comprehensive Epilepsy Program at Henry Ford Hospital in Detroit, and chair of the Foundation's professional advisory board.

"The Epilepsy Foundation would like to improve patient care by getting your agreement to collaborate and share individual registry data and publish updated summary data twice a year in a major journal," Barkley told the group.

"We would like to see a process established for the collection and publication of such data and discuss ways in which we can utilize voluntary health agencies, such as the International Bureau for Epilepsy, the Epilepsy Foundation and other professional organizations to disseminate this information."

Achieving that goal, it became clear during discussion, will be a challenge, primarily because the registries have different methods of enrollment, recruitment, and even in the type of information they gather.

Some recruit only women who are taking a particular drug and record fetal effects of that drug only; some accept only women with epilepsy; others include women who are taking epilepsy drugs for other conditions, such as migraine, nerve pain or mood disorders.

Some registries include a control group of women with epilepsy who are not taking medication against which drug effects on other women can be compared, while others do not.

In some countries the physician is the one who enrolls women (with their consent), while in the United States the decision to register is entirely up to the patient.

Despite these hurdles, however, it was felt that knowing consistent trends across studies of higher or lower risk associated with a specific drug would be of value, even if the studies were not directly comparable in scientific terms. .

The Foundation believes that the best way to achieve this would be to have each registry publish its results in a major publication, and then provide twice-yearly updates on current results. One benefit, it was pointed out, would be that the updates would allow for corrections if an earlier conclusion proved wrong.

Eric Hargis and Phil Lee, president of the International Bureau for Epilepsy and also representing the International League Against Epilepsy, both emphasized the importance to women of getting the information out as quickly as possible.

Hargis described the search for fetal risks associated with epilepsy drugs as a public health issue. "Women who take these drugs deserve to have the most updated information on what these products may do to their children because there is no second chance for them," he said.

The group also discussed how best to get the new information into journals read by other medical specialists other than neurologists, including obstetricians and gynecologists, psychiatrists and internists.

The meeting ended with a commitment from the participants to consult with the advisory boards of their registries about the publication proposals that had been made, and to meet again soon to formulate next steps.

The following registries were represented at the meeting: the North American AED Pregnancy Registry, the European Epilepsy Pregnancy Registry, the Worldwide Lamictal Registry, EURAP, the U.K. Epilepsy Pregnancy Registry and the Neurontin Pregnancy Registry.