CDC guidelines for preventing early-onset GBS disease recommend antibiotic prophylaxis for women who have:

• A. GBS colonization with cesarean section performed after onset of labor
• B. Unknown GBS status with no known risk factors
• C. GBS colonization with no risk factors
• D. Delivered a previous infant with GBS disease (correct)

Answer: (D)

Intrapartum antibiotic prophylaxis to prevent early-onset GBS disease is guided by risk factors present during labor. The strongest and most definitive indication is a history of delivering a previous infant with GBS disease. In that situation, antibiotics are recommended during labor to reduce the risk of GBS infection in the newborn, regardless of the mother’s current GBS status or other risk factors.

This is why the scenario of a prior infant with GBS disease is the best answer. While current GBS colonization or unknown status with other risk factors can also lead to prophylaxis, the prior affected infant represents a clear, high-priority trigger for giving antibiotics during labor.