Use of oral antifungal drugs during pregnancy may increase the risk of miscarriage, according to a large Danish study.
It found taking the oral antifungal fluconazole was associated with an increased risk of spontaneous abortion, compared with unexposed women and those using a topical antifungal.
“Oral fluconazole use in pregnancy was associated with a significantly increased risk of spontaneous abortion”
Pregnant women are at increased risk of yeast infection. Although intravaginal formulations of topical azole antifungals are first-line treatment for pregnant women, the study authors suggested that oral fluconazole was often used – despite limited safety information.
Their study included 1.4 million pregnancies in Denmark from 1997-2013. Oral fluconazole-exposed pregnancies were compared with up to four unexposed pregnancies, matched on maternal age, calendar year, and gestational age.
There was a significantly increased risk of miscarriage associated with fluconazole exposure, said the authors from the Statens Serum Institut in Copenhagen.
Among 3,315 women exposed to oral fluconazole from seven to 22 weeks gestation, 147 experienced a spontaneous abortion, compared with 563 among 13,246 women not exposed to antifungals.
However, there was no significant association between fluconazole exposure and stillbirth.
Among 5,382 women exposed to fluconazole from gestational week seven to birth, 21 experienced a stillbirth, compared with 77 among 21,506 unexposed matched women.
Using topical azole exposure as a comparison, 130 of 2,823 women exposed to fluconazole versus 118 of 2,823 exposed to topical azoles had a spontaneous abortion.
Meanwhile, 20 of 4,301 women exposed to fluconazole versus 22 of 4,301 exposed to topical azoles had a stillbirth.
“In this nationwide cohort in Denmark, oral fluconazole use in pregnancy was associated with a significantly increased risk of spontaneous abortion,” said the authors in the Journal of the American Medical Association.
“Until more data on the association are available, cautious prescribing of fluconazole in pregnancy may be advisable,” they said.
They added: “Although the risk of stillbirth was not significantly increased, this outcome should be investigated further.”