The Food and Drug Administration (FDA) will reexamine the proposed link between a common yeast infection drug called fluconazole and an increased risk of miscarriage, the agency announced Tuesday.

The decision comes in the wake of an extensive study published earlier this January in the Journal of the American Medical Association. The research analyzed the medical records of Danish women who had taken fluconazole orally while 7 to 22 weeks pregnant between 1997 and 2013, and compared their pregnancy outcomes to similarly matched women who hadn’t. They found a significant increased risk of miscarriage among those who had used the drug, and an increased but statistically nonsignificant risk of stillbirth.   

The agency will now evaluate the results of the study for themselves. “We are also reviewing additional data and will communicate our final conclusions and recommendations when our review is complete,” their announcement read.

Fluconazole has been the subject of scrutiny concerning pregnancy before. Animal studies have consistently shown a damaging impact on fetal health from its use, albeit at much higher doses than are ever given to humans. And several isolated case reports have shown a potential link between chronic high-dosage use of 400-800 milligrams a day in the first trimester of pregnancy and the rare occurrence of distinct skeletal and facial birth defects. The evidence for the latter was enough to convince the FDA in 2011 to categorize high-dosage fluconazole as a Category D risk for pregnant women. That indicated that heavy fluconazole use had a definite “human fetal risk based on human data,” but would be otherwise beneficial for women with serious or life-threatening conditions.

Until the Danish study, however, there hadn’t been any substantial evidence tying the drug’s more much common application — as a one- or two-time dose of 150 milligrams — to later fetal damage. Interestingly, the study didn’t find an increased risk in high-dosage fluconazole use, but the authors theorized that the sample size of these cases may have been too small for them to be able to detect any differences. After comparing its use with that of other antifungal drugs, they concluded that the added risk likely wasn’t due to the yeast infection itself.

Fluconazole has traditionally been used as a second-line treatment for recurring or especially severe yeast infections of the vagina, mouth, and esophagus. As much as 10 percent of pregnant women in the United States develop a vaginal yeast infection, making the question of fluconazole safety especially urgent.

Mirroring the Danish authors’ own conclusions, the FDA advises a “cautious prescribing of oral fluconazole in pregnancy” until their review is complete.

In the meantime, though, it is important to put the potential absolute risks of the drug in context, especially since miscarriages can be caused by a variety of different factors. Out of the 3,315 women exposed to fluconazole in the Danish study, only 147, or 4.43 percent, experienced a miscarriage; out of the 13,246 women not exposed to it, 563, or 4.25 percent, experienced the same.