Pregabalin use in early pregnancy may increase the risk of birth defects, according to researchers.
While it is unclear exactly how the drug works, researchers believe it binds to receptors on the brain's nerve cells to reduce pain signals.
According to the study researchers - including Ursula Winterfeld, Ph.D., of the Swiss Teratogen Information Service and Lausanne University Hospital in Lausanne, Switzerland - animal studies have suggested an increased risk of birth defects with pregabalin use in pregnancy.
However, they say that information on the effects of pregabalin use during pregnancy in humans in limited.
Pregabalin most commonly used for neuropathic pain in pregnancy
To address this research gap, Winterfeld and colleagues analyzed data of 820 women from seven countries, including France, the United Kingdom, Italy, Finland, Switzerland, the Netherlands, and Turkey.
Of these women, 164 used pregabalin during a pregnancy, while 656 did not take pregabalin or any other anti-seizure medication while they were pregnant.
Among the women who used pregabalin during pregnancy, 115 took it for neuropathic pain, 39 took it for psychiatric disorders - including anxiety, depression, and bipolar disorder - five took it for epilepsy, and one woman took it for restless leg syndrome.
Pregabalin use was initiated before pregnancy among 77 percent of these women, and use of the drug was stopped at an average of 6 weeks' gestation.
A total of 13 percent of the women who used pregabalin were also using other anti-seizure medications.
There were 116 pregnancies among the women who used pregabalin while expecting, and there were 580 pregnancies among non-users.
Birth defect risk three times greater for pregabalin users
The team found that seven (6 percent) of the women who used pregabalin during pregnancy had children with major birth defects, compared with 12 (2 percent) of women who did not use the drug.
Therefore, the findings indicate that the women who used pregabalin in the first trimester of pregnancy were around three times more likely to have a child with a major birth defect than non-users of the drug.
Heart defects and structural abnormalities in the central nervous system (CNS) - the brain and spinal cord - or other organs were among the most common birth defects.
Compared with expectant mothers who did not use pregabalin, those who did were six times more likely to have a pregnancy with a CNS birth defect.
Winterfeld notes that the researchers are unable to draw firm conclusions about the link between pregabalin use in pregnancy and the risk of birth defects, primarily because the study was small and many of the women were using other anti-seizure medications.
Still, she says the results indicate that caution should be applied when it comes to pregabalin use in early pregnancy.
"Pregabalin should be prescribed for women of childbearing 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."