A study of risk factors of vaginal colonization with group B streptococci in pregnancy.

Two hundred pregnant women were screened for vaginal Group B Streptococci carriage just before delivery. Fifty non-pregnant women were also examined. Vaginal colonization rate of pregnant women and of non-pregnant women was identical (12% in both groups). None of the personal and social characteristics investigated (age, profession, residence, marital status and education) were associated with higher or lower colonization rates. However the influence of the number of previous pregnancies proved to be significant, as pregnant women with 2 or more previous pregnancies tended to be more frequently colonized than primigravidae or secundigravidae women. These findings are discussed in relation to the possible reservoir of the microorganisms and the route of infection.