Effects of group B streptococcus infection on vaginal micro-ecology and pregnancy outcomes of pregnant women in late pregnancy

Abstract Background Invasive infection with group B streptococcus (GBS) can lead to intrauterine infection, and GBS can also spread via vertical transmission between mother and infant, resulting in adverse pregnancy outcomes. This study aimed to investigate the effects of GBS colonization in late gestation on vaginal micro-ecology, pregnancy outcomes and neonatal outcome. Methods One hundred and twenty pregnant women in the third trimester infected with GBS and 120 healthy counterparts who underwent a prenatal examination in the obstetrics department of the study hospital from June 2019 to December 2020 were selected for inclusion in the study. Vaginal micro-ecological index, mode of delivery, adverse pregnancy outcomes and neonatal Apgar score were compared between the two groups. Results The incidence rates of vaginal micro-ecological disorders, intrauterine infection and neonatal infection were significantly higher in the GBS group compared with the control group. The incidence rates of neonatal fetal distress and pathological jaundice were much higher in the GBS group compared with the control group. The neonatal Apgar score was markedly lower in the GBS group compared with the control group. Conclusions GBS infection is correlated with the vaginal micro-environment. GBS colonization in late pregnancy has adverse effects on vaginal micro-ecology and pregnancy outcome.