Maternal and neonatal infection rates with three different protocols for prevention of group B streptococcal disease

OBJECTIVES: We compared maternal and neonatal infection rates under 3 diffe rent group B streptococcal prevention strategies and also evaluated reasons for each protocol's failures in preventing neonatal disease. STUDY DESIGN: Women who were delivered at our center from August 1, 1991, t hrough April 30, 1998, were managed by 1 of 3 protocols for prevention of e arly-onset neonatal group B streptococcal infection: a selective screening protocol, The American College of Obstetricians and Gynecologists protocol, and the Centers for Disease Control and Prevention-recommended universal s creening strategy. We compared maternal infection rates and neonatal group B streptococcal infection rates under each protocol. We also compared reaso ns for each protocol's failures in preventing neonatal infection. RESULTS: Clinical chorioamnionitis rates were 7.4% with selective screening , 7.7% under The American College of Obstetricians and Gynecologists' proto col, and 5.2% with universal screening (relative risk 0.7, 95% confidence i nterval 0.6-0.8). Endometritis rates were 4.0% with selective screening, 4. 6% with The American College of Obstetricians and Gynecologists protocol, a nd 2.8% with universal screening (relative risk 0.7, 95% confidence interva l 0.6-0.8). Overall neonatal group B streptococcal infection rates were low er under the 2 more recent strategies, but not significantly so. Despite th e ability of universal screening to find more women at risk for group B str eptococcal transmission, half of the neonatal infections under this protoco l occurred when the mothers were not considered candidates for prophylaxis. CONCLUSIONS: The Centers for Disease Control and Prevention-endorsed univer sal screening strategy for group B streptococcal infection prevention was a ssociated with significantly lower rates of clinical chorioamnionitis and e ndometritis than were the other strategies. We were unable to document stat istically significant improvement in neonatal outcome under the universal s creening protocol.