Philosophiae Doctor - PhD / The aim of the study was to detect the prevalence of AV and its associated bacteria with preterm delivery in the Western Cape, South Africa. Furthermore, it sought particularly to examine and investigate the predictive value of GBS and E. faecalis for preterm delivery (PTD). It also aimed to establish other factors which may predict adverse pregnancy outcomes. Three hundred and one pregnant women were recruited from four different antenatal in the Western Cape, South Africa. The study conformed with the Declaration of Helsinki (2013). Maternal data was collected from a questionnaire and maternal medical records. Vaginal and rectal swabs were collected and microscopically examined for AV, followed by culture characterization of GBS and E. faecalis. Antimicrobial susceptibility testing was also performed. In this study, AV was detected in 79 (26.2%) of the 301 pregnant women, and GBS and E. faecalis isolated from 50 (16.6%) and 21 (7.0%) respectively. GBS serotype V was the predominant serotype, followed by serotype III. Pulse field gel electrophoresis (PFGE) profile analysis for both GBS and E. faecalis yielded a total of 24 restrictions profiles for GBS and 16 for E. faecalis. Multivariable analysis revealed that parity, gravidity, vaginal discharge, urinary tract infection, and smoking were significantly associated with PTD. The results from the study provides improved guidelines maternal screening of pregnant women. The early detection of AV-related bacteria may significantly reduce maternal and neonatal morbidity.