A drug used to treat fibromyalgia, epilepsy and other neuropathic conditions — pregabalin (marketed as Lyrica) — may be associated with an increased risk of major birth defects, including central nervous system and heart defects, especially if taken during the first trimester of a pregnancy. However, the researchers could not establish a clear link, partly because a number of the women studied were taking other medication, especially anti-seizure drugs.
The observational study, “Pregnancy outcome following maternal exposure to pregabalin may call for concern,” was published online in Neurology, the medical journal of the American Academy of Neurology (AAN).
Researchers collected information from seven countries on 164 women who took pregabalin during their pregnancy, and 656 pregnant women not on anti-seizure drugs, who were contacted after giving birth. (Pregabalin is approved by the U.S. Food and Drug Administration (FDA) for fibromyalgia and neuropathic pain, or pain associated diabetic neuropathy, shingles, and spinal cord injury. It also is approved to treat partial onset seizures in adults with epilepsy, who are taking one or more seizure medications.)
Results showed that women who took pregabalin during the first trimester of pregnancy were three times more likely to have a child with major birth defects than those who did not take anti-seizure drugs. Specifically, seven of 116, or 6%, of women using pregabalin early in their pregnancy had a child with birth defects, compared to 12 of 580 women, or 2%, who did not use the drug.
Data also showed that 77% of the women using pregabalin started taking it before they got pregnant, and all had stopped its use, on average, six weeks into their pregnancy. But 22 of these women (13%) were also taking another anti-seizure drug. The reasons for pregabalin use ranged from neuropathic pain (115 women) or psychiatric disorders (39) like depression, anxiety, bipolar disorder or psychosis, to epilepsy (5) and restless leg syndrome (1).
Major birth defects observed included heart defects and structural problems with the babies’ central nervous system (CNS). A sixfold increased risk of a child with a major defect in the CNS was found in women taking pregabalin, with four CNS defects observed in 125 of these pregnancies, or 3,2% of births, compared to three CNS defects found in 570 observed pregnancies among non-users, or 0.5%.
The study did not include any birth defects due to chromosomal abnormalities.
“We can’t draw any definitive conclusions from this study, since many of the women were taking other drugs that could have played a role in the birth defects, and because the study was small and the results need to be confirmed with larger studies,” Ursula Winterfeld, PhD, a researcher with the Swiss Teratogen Information Service and Lausanne University Hospital, said in a press release. “But these results do signal that there may be an increased risk for major birth defects after taking pregabalin during the first trimester of pregnancy.
“Pregabalin should be prescribed for women of child-bearing age only after making sure that the benefits of the drug outweigh the risks and after counseling them about using effective birth control. In cases where women have taken pregabalin during pregnancy, extra fetal monitoring may be warranted,” Dr. Winterfeld added.