Background: HIV and lower genital tract bacterial colonization independently have documented associations with pregnancy outcomes, which is compounded by rapidly escalating antimicrobial resistance. Objectives: To determine interactive effects of HIV and bacterial colonization on low birthweight and preterm birth. Search Strategy: To identify relevant studies, we systematically searched databases (Medline, Embase, CINAHL, Scopus, Web of Science, Cochrane Library, and African Journals Online) from inception until December 2023. Selection criteria: we included observational studies that reported on pregnancy outcomes stratified by vaginal colonization and HIV status. Data collection and analysis: Meta-analysis was conducted using random-effects modelling, reported as pooled log-odds ratios. Main results: We included 13 studies in which 5,807 were identified. The 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) but borderline increased odds of preterm birth(OR:2.64; 95%CI:−0.01,1.94, p=0.05). There were no significant associations between HIV and bacterial colonization(OR:1.08; 95%CI:−0.91,1.07) nor in antimicrobial resistance between pregnant women with HIV and those without. Conclusions: Bacterial colonization is prevalent among pregnant women, but there is no clear evidence to suggest that HIV and lower genital tract bacterial colonization interact to affect birth weight or preterm birth. Research with large sample sizes, strict selection criteria, reliable/valid measurement, and adequate control for confounding variables, with birthweight and gestational age as continuous outcomes, are still needed to provide robust evidence. Funding: NIH-Fogarty International; D43 Research Training Grant to CUHAS and Global Affairs-Canada; Study in Canada Scholarship provided financial support. Keywords: vaginal bacterial colonization, HIV, adverse pregnancy outcomes, preterm birth, low birth weight.