ROLE OF MALE PARTNER TREATMENT IN PREVENTING RECURRENT VAGINAL MICROBIOME DISTURBANCES DURING PREGNANCY

Abstract

Recurrent disturbances of the vaginal microbiome during pregnancy represent an important clinical concern because alterations in microbial composition may influence maternal reproductive health and pregnancy outcomes. A healthy vaginal microbiome is generally characterized by the predominance of Lactobacillus species, which contribute to maintenance of an acidic vaginal environment and provide protection against the overgrowth of potentially pathogenic microorganisms. In contrast, vaginal dysbiosis, including bacterial vaginosis (BV), is associated with increased microbial diversity, depletion of protective Lactobacillus species, and enrichment of anaerobic bacteria such as Gardnerella, Prevotella, and Atopobium. These alterations have been associated with adverse pregnancy outcomes, including preterm birth, premature rupture of membranes, and low birth weight (Zhou et al., 2024; [Authors], 2023).

Recurrence following conventional treatment remains a major challenge, suggesting that management strategies directed exclusively toward the female partner may not adequately address factors contributing to persistent or recurrent dysbiosis. Increasing evidence indicates that sexual partners may contribute to the persistence or reintroduction of BV-associated microorganisms. A prospective pilot study published in 2021 demonstrated that concurrent treatment of male partners was associated with changes in the composition of both vaginal and penile microbiota, supporting the possibility of sexual exchange of BV-associated organisms (Plummer et al., 2021). However, an earlier randomized controlled trial published in 2021 found that treatment of male partners with oral metronidazole alone did not significantly reduce BV recurrence among female partners, highlighting the importance of treatment regimen and adherence (Schwebke et al., 2021).

More recently, the StepUp randomized controlled trial provided important evidence that combined oral and topical antimicrobial treatment of male partners can substantially reduce BV recurrence compared with treatment of women alone. In this study, recurrence within 12 weeks occurred in 35% of women receiving concurrent male-partner treatment compared with 63% in the standard-care group (Vodstrcil et al., 2025). A 2026 systematic review and meta-analysis further emphasized that the effectiveness of partner treatment may depend on the treatment regimen, with combined oral and topical therapy showing greater potential than male-partner monotherapy.

Given the established relationship between vaginal microbiome disturbances and adverse pregnancy outcomes, investigating whether treatment of male partners can reduce recurrent dysbiosis during pregnancy represents a promising area of research. Nevertheless, the safety, effectiveness, optimal timing, and appropriate antimicrobial regimen for male-partner treatment specifically among pregnant populations require rigorous evaluation. The present study therefore aims to examine the potential role of male-partner treatment in reducing recurrent vaginal microbiome disturbances during pregnancy and to explore whether a partner-directed approach may contribute to improved vaginal microbial stability and potentially better maternal and fetal outcomes.