Lyrica or pregabalin, a widely prescribed drug  commonly taken for epilepsy, fibromyalgia and anxiety, may increase the risk of birth defects according to a new study.

Researchers from Lausanne University Hospital in Switzerland looked into the effects of the drug through a study that looked at 164 women who took Lyrica during pregnancy. They found that taking the drug during the first trimester, 6 percent of those had babies with a major birth defect while those that hadn’t taken Lyrica only 2 percent experienced major birth defects.

Despite the study’s findings it is not significant enough to directly link Lyrica to the birth defects and can only be a warning to those taking the drug and planning a family, according to U.S. News and World Report.

The study was led by Dr. Thierry Buclin who had previously linked birth defects with Lyrica in pregnant animals but was unable to conclude the findings since animals and humans have different reactions to drug chemicals and different types of pregnancies.

“These results should be taken with caution,” stated Dr. Buclin. “It’s a warning, but it cannot be taken as a certainty.”

The limitations were not only towards the size of the study but also did not take into account any other drugs that the pregnant women were taking.

The birth defects linked to Lyrica included heart defects and problems with the central nervous system or other organs. Experts advise pregnant women and those planning pregnancy who take the drug, to discuss further options with their doctor. Dr. Page Pennell, an associate professor of neurology at Harvard Medical School in Boston, states that for many reasons some women may need to keep taking Lyrica during pregnancy but risk assessments need to be “weighed against the need to maintain maternal disease control.”

The study was published in the journal Neurology.