Pregnancy is a delicate time for the body — and it's not always easy to see where the dangers lie. According to a Scandinavian study, published in the Journal of the American Medical Association (JAMA), use of the oral antifungal medication fluconazole, which can treat a number of fungal and yeast infections, during pregnancy is associated with an increased risk of spontaneous abortion.
Pregnancy means an increased risk of the yeast infection known as vaginal candidiasis. It is estimated that around 10% of pregnant women in the United States develop the problem at some stage. Although, generally, topical antifungals are a recommended first-line treatment for pregnant women, oral fluconazole is often used despite the limited safety information available — possibly because they are simply easier to take than a topical medicine is to apply.
A team of researchers led by Ditte Molgaard-Nielsen, of the Statens Serum Institut in Copenhagen, examined the association between oral fluconazole exposure during pregnancy and the risk of spontaneous abortion and stillbirth. The analysis of approximately 1.4 million pregnancies in Denmark shows that the risk of losing a baby is increased in users of oral medication when compared to unexposed women and those who used a topical antifungal treatment while pregnant.
The team analyzed data from 1,405,663 pregnancies that occurred in Denmark between 1997 and 2013. Using information from the National Prescription Register, the pregnancies of oral fluconazole-exposed women were compared with up to four unexposed individuals who they matched on maternal age, calendar year and gestational age.
Among 3,315 women exposed to oral fluconazole from 7 through 22 weeks' gestation, 147 (or 4.3%) experienced a spontaneous abortion. This compared to a figure of 563 (or 4.25) among 13,246 women among those not exposed to antifungals. The researchers say this shows a significantly increased risk of spontaneous abortion associated with fluconazole exposure. However, among 5,382 women exposed to fluconazole from gestational week 7 to birth, 21 (0.39%) experienced a stillbirth, compared with 77 (or 0.36%) among 21,506 unexposed matched women. This, the team says, shows no significant association between fluconazole exposure and stillbirth.
The team compared these figures with those from women who had used topical treatment. Of the 2,823 women exposed to fluconazole, 130 (or 4.61%) had a spontaneous abortion compared to 118 (4.18%) of the 2823 who used topical azoles. And 20 (or 0.47%) of the 4,301 women exposed to fluconazole suffered a stillbirth compared to 22 (or 0.51%) of those 4,301 women who chose topical azoles.
The new research might be particularly worrying as oral fluconazole treatments are available over the counter and so are particularly open to misuse. If you think you are suffering from vaginal candidiasis or any other infection, talk to your doctor or other healthcare specialist — especially if you are (or you think you might be) pregnant. Although further research is needed, the Danish team urges caution.
"In this nationwide cohort in Denmark," the team says, "oral fluconazole use in pregnancy was associated with a significantly increased risk of spontaneous abortion. Until more data on the association are available, cautious prescribing of fluconazole in pregnancy may be advisable. Although the risk of stillbirth was not significantly increased, this outcome should be investigated further."