Combined effects of bacterial vaginal colonization and HIV on pregnancy outcomes: A Systematic Review and Meta-analysis

The independent effects of HIV and bacterial vaginal colonization on adverse pregnancy outcomes are well established and may be exacerbated by increasing antimicrobial resistance (AMR). However, their combined association with pregnancy outcomes has not been comprehensively evaluated. We conducted a systematic review and meta-analysis to assess the joint effects of HIV and vaginal bacterial colonization on birth weight, preterm birth (PTB), and AMR. MEDLINE, EMBASE, CINAHL, Scopus, Web of Science, Cochrane Library, African Journals Online, and PubMed were searched for observational studies published through December 31, 2023. Eligible studies reported vaginal bacterial colonization stratified by HIV status and pregnancy outcomes. Study quality was assessed using the Newcastle–Ottawa Scale, and pooled odds ratios (ORs) were estimated using random-effects models. Thirteen studies involving 5,807 pregnant women were included. The pooled prevalence of bacterial vaginal colonization was 26% (95% CI: 17.3–37.4%; I²= 97.4%). No significant association was observed between HIV-associated bacterial colonization and birth weight (OR = 1.20, 95% CI: 0.08–9.03; p = 0.88). Although the pooled estimate suggested increased odds of PTB, the association did not reach statistical significance (OR = 2.64, 95% CI: 0.99–6.96; p = 0.05). HIV infection was not significantly associated with bacterial vaginal colonization (OR = 1.08, 95% CI 0.40–2.92), and no significant differences in AMR patterns were identified between women with and without HIV. Current evidence does not support a significant combined effect of HIV and bacterial vaginal colonization on birth weight or PTB. Larger, methodologically robust prospective studies are needed to clarify these relationships.