GBS is the most common cause of serious infections in neonates, occurring at 1.8/1000 live births. The combination of late prenatal screening for GBS colonization and intrapartum antibiotic prophylaxis (IAP) of carriers and preterm deliveries was estimated to prevent about 86% of EOGBS disease. The purpose of this paper is to evaluate the incidence of EOGBSand the prevalence of maternal risk factors from 1992 to 1996 in 11 U.S. hospitals. Cases for 1992-4 were identified by retrospective review of microbiology records, computerized data bases, and nursery log books. Cases for 1995-6 were identified by prospective active case finding. Medical records of mothers and infants were reviewed for maternal risk factors. In 1992-4, 168 EOGBS cases were identified (1.5/1000 live births); 64% were bom to mothers with at least one published risk factors. In 1995-6, 63 EOGBS were identified (1.2/1000). The %of EOGBS born to mothers with at least one risk factor decreased from 64% to 37%(p<0.001). Examination of each risk factor in 119 cases whose data are in the database showed a significant decrease in % cases bom to mothers with rupture of membranes >18h (27% vs 10%, p= .006),or mothers with fever (32% vs 10%, p=.0007). A decrease was noted in % cases born at <37 weeks (18% vs 13%), or to mothers with positive antenatal GBS culture (12% vs 8%). Our data suggest that the implementation of IAP might have impacted the number of cases bom to mothers with risk factors. Despite IAP, the incidence of EOGBS remains significant, with 60 % EOGBS cases born to mothers without risk factors, and thus are non-preventable by currently recommended prevention strategies. Our data suggest that IAP does not eliminate EOGBS, and vaccination of women of child bearing age may be necessary to protect infants from GBS disease.