Objective  To observe the risk factors of group B Streptococcus (GBS) infection in late pregnancy, and to analyze the possible risk factors.

  Methods  A total of 1 500 pregnant women in late pregnancy who received regular prenatal GBS screening were selected. The general situation questionnaire was designed, and the clinical data of pregnant women were recorded in details. The univariate and multivariate analysis were used to find out the influencing factors of GBS infection in late pregnancy.

  Results  Among 1 500 pregnant women in late pregnancy, 225 cases of positive GBS were detected, accounting for 15.00%; the incidence of adverse outcomes such as premature birth, infant of low-birth weight, premature rupture of membranes in non-infection group was lower than that in the infection group (P < 0.05); multiple Logistic regression analysis showed that recurrent vaginitis in pre-pregnancy, early pregnancy and mid-pregnancy, gestational diabetes, gestational hypertension, gestational anemia, living environment in rural areas, high body mass index before pregnancy may be the influencing factors for GBS infection in late pregnancy (OR>1, P < 0.05).

  Conclusion  GBS infection in late pregnancy is affected by recurrent vaginitis in pre-pregnancy, early pregnancy and mid-pregnancy, gestational diabetes, gestational hypertension, gestational anemia and other factors.