Patterns of Yeast Infections and Antifungal Use in the First Trimester of Pregnancy: Findings from the Birth Defects Study to Evaluate Pregnancy exposureS, 2014-2019.

Background: Yeast infections are common during pregnancy. Understanding their current prevalence and corresponding treatments during pregnancy is important. We used data from a U.S. population-based retrospective study of recently pregnant people to describe patterns of first trimester maternal yeast infections and antifungal use. Materials and Methods: Using a cohort of control participants from the Birth Defects Study to Evaluate Pregnancy exposureS, self-reports of first trimester yeast infections and antifungal use were collected via computer-assisted telephone interviews for births during 2014-2019. We described maternal characteristics and examined the prevalence of yeast infections and antifungal use overall and by study site and birth year. Tests for trend were used to evaluate changes over the study period. Results: After exclusions, there were 1,524 control participants included in our sample. First trimester yeast infections (9.8%) and antifungal use (8.6%) were common. More participants reported prescription (52.7%) than over-the-counter (45.0%) antifungals; most users reported a topical antifungal (72.5%). Prevalence of yeast infections and antifungal use increased modestly, but nonsignificantly, over the study period, ranging from 7.8% to 10.9% for yeast infections and 7.2% to 9.8% for antifungal use. Prevalence of topical and over-the-counter antifungals significantly increased over the study period; use of oral and prescription antifungals modestly decreased. Conclusions: In our cohort, first trimester yeast infections and antifungal use were relatively common and modestly increased throughout the study period, although this trend was not significant. We observed significant increases for topical and over-the-counter antifungals. Additional research is needed to investigate the reasons behind these prevalence changes.