Early-onset group B streptococcus sepsis in high risk neonates born after prolonged rupture of membranes

Background: According to the U.S. Centers for Disease Control guidelines, prolonged rupture of membranes mandates intrapartum antimicrobial prophylaxis for group B Streptococcus whenever maternal GBS status is unknown. Objectives: To evaluate the local incidence, early detection and outcome of early-onset GBS sepsis in neonates born at 35-42 weeks gestation after PROM to women with unknown GBS status who were not given intrapartum antimicrobial prophylaxis. Methods: During a 1 year period we studied all neonates born beyond 35 weeks gestation with maternal PROM ≥ 18 hours, unknown maternal GBS status and without prior administration of IAP. Complete blood count, C-reactive protein, blood culture and polymerase chain reaction amplification of bacterial 16S rRN A gene were performed in blood samples collected immediately after birth. Unfavorable outcome was defined by one or more of the following: GBS bacteremia, clinical signs of sepsis, or positive PCR. Results: Of the 3616 liveborns 212 (5.9%) met the inclusion criteria. Only 12 (5.7%) of these neonates presented signs suggestive of sepsis. PCR was negative in all cases. Fifty-eight neonates (27.4%) had CRP > 1.0 mg/dl and/or complete blood count abnormalities, but these were not significantly associated with unfavorable outcome. Early-onset GBS sepsis occurred in one neonate in this high risk group (1/212 = 0.47%, 95% CI 0.012-2.6). Conclusions: In this single-institution study, the incidence of early-onset GBS sepsis in neonates born after PROM of ≥ 18 hours, unknown maternal GBS status and no intrapartum antimicrobial prophylaxis was 0.47%.