Risk factors for early-onset group B streptococcal sepsis: Estimation of odds ratios by critical literature review

Objective. To identify and to establish the prevalence of ORs for factors a ssociated with increased risk for early-onset group B streptococcal (EOGBS) infection in neonates. Study Design. Literature review and reanalysis of published data. Results. Risk factors for EOGBS infection include group B streptococcal (GB S)-positive vaginal culture at delivery (OR: 204), GBS-positive rectovagina l culture at 28 (OR: 9.64) or 36 weeks gestation (OR: 26.7), vaginal Strep B OIA test positive at delivery (OR: 15.4), birth weight less than or equal to 2500 g (OR: 7.37), gestation <37 weeks (OR: 4.83), gestation <28 weeks (OR: 21.7), prolonged rupture of membranes (PROM) >18 hours (OR: 7.28), int rapartum fever >37.5 degrees C (OR: 4.05), intrapartum fever, FROM, or prem aturity (OR: 9.74), intrapartum fever or FROM at term (OR: 11.5), chorioamn ionitis (OR: 6.43). Chorioamnionitis is reported in most (88%) cases in whi ch neonatal infection occurred despite intrapartum maternal antibiotic ther apy. ORs could not be estimated for maternal GBS bacteriuria during pregnan cy, with preterm premature rupture of membranes, or with a sibling or twin with invasive GBS disease, but these findings seem to be associated with a very high risk. Multiple gestation is not an independent risk factor for GB S infection. Conclusions. Mothers with GBS bacteriuria during pregnancy, with another ch ild with GBS disease, or with chorioamnionitis should receive empirical int rapartum antibiotic treatment. Their infants should have complete diagnosti c evaluations and receive empirical treatment until infection is excluded b y observation and negative cultures because of their particularly high risk for EOGBS infection. Either screening with cultures at 28 weeks gestation or identification of clinical risk factors, ie, FROM, intrapartum fever, or prematurity, may identify parturients whose infants include 65% of those w ith EOGBS infection. Intrapartum screening using the Strep B OIA rapid test identifies more at-risk infants (75%) than any other method. These risk id entifiers may permit judicious selection of patients for prophylactic inter ventions.