The Centers for Disease Control and Prevention estimate that 75 percent of all adult women have experienced a vaginal yeast infection at some point in their lifetime; thankfully, these infections are easily treated. But a new study suggests pregnant women may need to be especially cautious when treating an infection. According to the research, the oral antifungal medication fluconazole is associated with a greater risk of spontaneous abortion than topical azole antifungals creams and suppositories.

For a recent study, now published in the Journal of American Medicine Association, researchers from the Statens Serum Institut in Copenhagen, Denmark, analyzed the pregnancy risk associated with popular topical and oral yeast infection medications by using information from 1,405, 663 pregnancies occurring in Denmark between 1997 and 2013. From this data, the team determined that about 4.43 percent of the 3,315 women who were exposed to oral fluconazole between their 7th and 22nd week of pregnancy experienced a spontaneous abortion, also known as a miscarriage. This was compared to around 4.25 percent of women who were not exposed to fluconazole during their pregnancy. In addition, 130 of the 2,823 women who used oral fluconazole experienced a miscarriage, while only 118 out of 2,823 women who used a topical azole had the same experience. However, it must be noted that the use of fluconazole did not seem to increase a woman's risk of stillbirth.

The American Pregnancy Organization states that yeast infections are common for pregnant women, especially during the second trimester, where many of the hormonal changes associated with pregnancy take place. These hormonal changes lead to more sugar in vaginal secretions — since yeast feed on sugar, this increased presence can lead to a burst in yeast populations.

While the risk for miscarriage may seem small, according to the researchers, these results show there is a significant increased risk associated with the oral fluconazole pregnant women use to treat vaginal yeast infections. In addition, the study estimates that around 10 percent of pregnant women in America experience a yeast infection, making the need for proper treatment of these women essential.

The most common treatment for vaginal yeast infections is a topical or suppository azole antifungal cream. Sometimes, though, a doctor may prescribe the oral antifungal medication fluconazole. However, fluconazole is associated with minor side effects, such as an upset stomach or headaches.

This is not the first time fluconazole use in pregnant women has been flagged for safety concerns. According to the study, the drug works to kill fungus populations by inhibiting the function of an enzyme needed to create cell membranes. It can also interfere with the enzymes expressed during utero development. Not many scientific studies have investigated the true risk fluconazole use poses to pregnancy, but already many physicians are hesitant to give this medication to pregnant women due to unknown effects it may have on an unborn child.

According to the researchers, until more data is available, doctors should still practice caution when prescribing fluconazole during pregnancy.

Source:Mølgaard-Nielsen D, Svanström, Henrik, Melbye M, Hviid A, Pasternak B. Association Between Use of Oral Fluconazole During Pregnancy and Risk of Spontaneous Abortion and Stillbirth. JAMA . 2016.