Despite progress in preventing infant group B streptococcal disease, group B streptococcus remains the leading cause of early-onset neonatal sepsis in the United States. Fortunately, most women who are colonized with group B streptococcus receive therapy and antibiotic prophylaxis is effective. However, the only factor associated with missed chemoprophylaxis is the short duration of time between hospital admission and delivery. Although antibiotic prophylaxis given for at least 2 hours shows some pharmacological benefit, the most effective method of preventing early-onset group B streptococcus disease is 4 hours of therapy. Intrapartum management strategies might be modified to improve the efficacy of antibiotic exposure. Obstetricians should consider strengthening the beneficial effect of intrapartum antibiotic prophylaxis for infants exposed to group B streptococcus by providing at least 4 hours of treatment coverage.