Interactive effects of bacterial vaginal colonization and HIV on pregnancy outcomes: a systematic review and meta-analysis.

BackgroundThe independent impact of HIV and bacterial vaginal colonization on pregnancy outcomes has been documented and is compounded by the burden of rapidly escalating antimicrobial resistance. However, the interactive effect of HIV and lower genital tract bacterial colonization, on pregnancy outcomes has not been thoroughly studied and is examined in our study. MethodsWe performed a systematic review and meta-analysis to quantitatively assess the interaction between HIV and vaginal bacterial colonization and associations with birth weight and preterm birth. We searched Ovid MEDLINE, Ovid EMBASE, CINAHL, Scopus, Web of Science, Cochrane Library, African Journals Online, and PubMed databases to identify studies published up to December 31, 2023. We included observational reporting on vaginal colonization with bacterial pathogens stratified by HIV status that reported pregnancy outcomes. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and used a modified Newcastle-Ottawa Scale to assess study quality. Meta-analysis was conducted using random-effects modeling in STATA Version 18. Pooled log-odds ratios were calculated. The study protocol was registered in PROSPERO(CRD42023485123). ResultsWe selected 13 studies, involving 6,073 pregnant women, from 5,807 studies identified. The overall pooled prevalence of bacterial colonization was 26%(95%CI:17.3-37.4). There was no significant effect of HIV status and vaginal colonization on birth weight(OR=1.2, 95%CI:-2.57-2.20, p=0.88) and borderline increased odds of preterm birth (OR=2.64, 95%CI:-0.01-1.94, p=0.05). There was no significant association between HIV status and bacterial colonization(OR=1.08, 95%CI =-0.91-1.07), nor in antimicrobial resistance between pregnant women with HIV and those without. ConclusionBacterial colonization is prevalent among pregnant women, but there is no clear evidence to suggest that HIV and bacterial colonization interact to affect birth weight or preterm birth. Research with large sample sizes, strict selection criteria, reliable and valid measurement, adequate control for confounding variables, and birthweight and gestational age at delivery assessment as continuous outcomes are still needed to provide robust evidence.