Relationship between maternal group B streptococcal colonization and pregnancy outcome.
OBJECTIVE
To examine the association of maternal colonization with group B streptococcus (GBS) with preterm labor and premature rupture of the membranes (PROM).


METHODS
Vaginal cultures were conducted in 615 women at 22-26 weeks' gestation and again on admission for term delivery, preterm labor, or PROM. Antibiotics were not given antenatally based on a GBS-positive culture result. Fisher exact test and maximum likelihood analysis were used for statistical analysis.


RESULTS
The rates of preterm labor and PROM were not significantly different between GBS-positive and GBS-negative women in both the antenatal screening and the screening on admission. According to maximum-likelihood analyses, the known risk factors for preterm labor and PROM collectively were important risk factors for preterm labor (odds ratio: 6.48), but GBS colonization during pregnancy was not a risk factor for preterm labor or PROM. In the antenatal screening, the proportion of subjects with lactobacilli-reduced vaginal flora was significantly higher in GBS-positive women (14.3%; ten of 70) than in GBS-negative women (6.4%; 35 of 545) (P = 0.26). Bacteria associated with bacterial vaginosis (Gardnerella vaginalis and anaerobes) were isolated in only 3.7% (23 of 615) of all subjects.


CONCLUSIONS
Vaginal colonization with GBS was not associated with preterm labor and PROM in an obstetric population with a low incidence of bacterial vaginosis-associated bacteria, despite the presence of lactobacilli-reduced flora in GBS-positive women.
Kubota
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Department of Obstetrics and Gynecology, Juntendo University, Juntendo Urayasu Hospital, Chiba, Japan.
D000328:Adult; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000382:microbiology*; D006801:Humans; D007752:Obstetric Labor, Premature / Q000382:microbiology*; D011247:Pregnancy; D011256:Pregnancy Outcome; D013292:Streptococcus agalactiae / Q000302:isolation & purification*; D014621:Vagina / Q000382:microbiology*