Hormonal Contraceptive Use and Risk of Sexually Transmitted Infection
The global incidence of sexually transmitted infections (STIs) is high, which has adverse effects on sexual and reproductive health outcomes. Given the widespread use of hormonal contraceptives (HC), it is important to consider their potential etiological association with acquisition of STIs. In a systematic review and meta-analysis recently published in Scientific Reports(1), Akter et al. examined associations between HC use (progesterone-only, combined estrogen-progesterone, or unspecified) and prevalence, incidence, or recurrence of STIs, compared with a control group of non-users of HC. A positive association with HC use was observed for risk of chlamydia trachomatis and herpes simplex virus type 2, in contrast to a negative association for risk of trichomoniasis and bacterial vaginosis. Importantly, only around half of all associations included in the meta-analysis were adjusted for condom use. Furthermore, while a plausible biological explanation based on the interaction between pathogen, host immune response, and vaginal microbiome can be proposed for these findings, the effects of differential sexual behavior, testing,...