Table 1.

Risk Factors Associated With Early-onset Neonatal Group B Streptococcal Infection

Risk FactorPrevalence
Estimated gestational age
 <28 weeks0.821.7
 28–30 weeks0.910.0
 31–33 weeks2.14.65
 34–36 weeks6.52.19
 ≥37 weeks89.71.00
Intrapartum fever or PROM6.811.5
Maternal GBS colonization:
 + Rectovaginal culture at 35–37 weeks* 20.426.7
 + Vaginal culture at delivery14.7204
 + Strep B OIA at delivery16.615.4
  • Abbreviations: PROM, prolonged rupture of membranes; GBS, group B streptococcus.

  • * Prevalence reflects a rectovaginal colonization rate of 22.8% in the 89.7% of parturients who deliver at term; odds ratio applies only to screened infants.