Reduction of group B streptococcal maternal and neonatal infections in preterm pregnancies with premature rupture of membranes through a rapid identification test.

To establish the effect of rapid detection and chemoprophylaxis of group B streptococcal genital colonization in preterm gestations with premature rupture of membranes, 260 singleton pregnancies were cultured. Through the use of a rapid test based on coagulation methods, group B streptococcus was identified in 84 (32%) patients, of which 18 (7%) had heavily colonized infections. The treatment of 36 patients resulted in no cases of chorioamnionitis or neonatal sepsis compared with 11 (23%) cases of chorioamnionitis and 13 (27%) of neonatal sepsis among 48 untreated patients (p less than 0.01). Although the risk of infection was significantly higher in patients with heavily colonized infections, characterized by less than 5 hours' growth for detection, even light colonization, requiring 20 hours for detection, resulted in a 14% rate of maternal and 16% rate of neonatal infection, respectively.