Untreated asymptomatic group B streptococcal bacteriuria early in pregnancy and chorioamnionitis at delivery.

OBJECTIVE: The objective of the study was to determine the frequency of adverse pregnancy outcomes in women with untreated asymptomatic group B beta-hemolytic streptococcal (GBS) bacteriuria during pregnancy.

STUDY DESIGN: In this retrospective cohort, all women with antepartum GBS bacteriuria in a research registry were included. Controls were women with negative urine cultures. The frequency of chorioamnionitis was compared between groups. Chorioamnionitis was defined as intrapartum fever, fetal tachycardia, and histologic inflammation of the membranes.

RESULTS: One hundred twenty-two women with bacteriuria (study group) and 183 women with negative antepartum cultures (controls) were included. There were no differences in demographic characteristics between the groups. Thirty-one women (10.2%) had chorioamnionitis. Untreated GBS bacteriuria was associated with chorioamnionitis after controlling for confounding variables, adjusted odds ratio 7.2 (95% confidence interval 2.4 to 21.2). There was also a significant positive rank correlation between increasing colony count of GBS bacteriuria and increasing grade of chorioamnionitis (P = .02).

CONCLUSION: Untreated antepartum GBS bacteriuria is associated with chorioamnionitis.