The Role of Probiotics in Primary and Secondary Prevention of Vulvovaginitis during Pregnancy and Preterm Labor: A Systematic Review.

OBJECTIVES

To evaluate the effectiveness and safety of oral probiotic supplementation for the primary prevention of vulvovaginal infections and preterm birth in pregnant women.

METHODS

A systematic review (PROSPERO 1129806) of randomized, placebo-controlled studies evaluating oral probiotics in pregnant women was conducted using PubMed, Virtual Health Library, Scopus, Cochrane Library, Web of Science, and Embase databases (2002-2025). The studies published in English assessing probiotics for vulvovaginitis or preterm birth prevention were included.

RESULTS

Four primary prevention studies were included, all used oral probiotics containing Lactobacillus rhamnosus, and no severe adverse events were reported. One study demonstrated reduced abundance of Candida albicans and Candida glabrata and increased beneficial lactobacilli following probiotic use after antifungal treatment. However, none of the studies showed a statistically significant effect on vulvovaginitis or preterm birth. The largest study indicated a non-significant trend toward reduced preterm birth among women with asymptomatic intermediate bacterial vaginosis.

CONCLUSIONS

Oral probiotics appear to be safe during pregnancy but are not effective as standalone therapy for vulvovaginitis. Combined approaches may provide benefit. Vaginal administration and specific species may offer greater efficacy. Further studies are needed, particularly regarding preterm birth prevention.