Risk Factors Associated with Group B Streptococcus Colonization and Their Effect on Pregnancy Outcome

Background: Group B Streptococcus (GBS) is an important cause of maternal and neonatal morbidity and mortality in many parts of the world. It has been implicated in adverse pregnancy outcomes. Maternal colonization has been found to be a major risk factor for invasive neonatal GBS disease. The main objective of this study was to identify the risk factors of Group B streptococcus colonization and its effect on pregnancy outcome. Methods: This was a prospective study in which pregnant women attending antenatal clinic (ANC) at Dr George Mukhari Hospital (DGMH) were recruited. These were at least18 years old and were at 16 weeks gestation. Vaginal and rectal swabs were taken at recruitment. Follow up of mothers until six weeks post-delivery and babies until three months of age was done. Results: A total of 340 pregnant women were then investigated for GBS colonization. Out of this number, 164 (48.2%) were GBS positive. The majority of the women (62.1%) were parity 1 and 2. Group B Streptococcus colonization was significant in women who had no matric education and who were unemployed. There was a significantly higher GBS colonization in women with previous history of miscarriages and stillbirths. The proportion of HIV positive, GBS colonized women was significant at 41.5% as compared to HIV negative GBS colonized (34.7%). Eight women (4.9%) presented with premature rupture of membranes (PROM) and the duration ranged from 0.5 to 72 hours. Ten (6.1%) women had preterm deliveries. Three (1.8%) women had wound sepsis post caesarean section and one (0.6%) had endometritis post vaginal delivery. A total of 7 (24.1%) babies were GBS positive. The number of live babies delivered was 167, with 1 case of miscarriage due to severe preeclampsia. There were 2 cases of early neonatal deaths which included 1 case of sepsis whereas the other one had multiple congenital abnormalities. Conclusion: Colonization by GBS in pregnant women at DGMH was high. Maternal risk factors identified were previous history of stillbirths/miscarriages, lack of education and being HIV positive. Overall pregnancy outcome both maternal and foetal was good.