What is the purpose of group B streptococcus (GBS) screening at 35-37 weeks, and how is positive status managed during labor?

• A. To treat maternal infection
• B. To assess fetal lung maturity
• C. To determine mode of delivery
• D. To prevent neonatal GBS infection; intrapartum antibiotics (penicillin G) for positive or unknown with risk factors

Answer: (D)

Screening at 35-37 weeks is done to identify whether a pregnant person is colonized with group B streptococcus so we can prevent passing it to the newborn during labor. GBS infection in newborns can be serious, so knowing who carries the bacteria allows us to use intrapartum antibiotics to protect the baby. If the screen is positive, IV penicillin G given during labor markedly reduces neonatal risk. The same preventive approach is used when the status is unknown but risk factors are present during labor. This strategy is specifically about preventing neonatal GBS disease, not about fetal lung maturity, maternal infection treatment, or choosing the mode of delivery. Antibiotic choice centers on penicillin G as the first-line option, with alternatives guided by allergy and susceptibility if needed.