When is limited diagnostic evaluation and antibiotic therapy indicated for a newborn with GBS?

Limited diagnostic evaluation and antibiotic therapy for a newborn with Group B Streptococcus (GBS) is indicated when maternal antibiotic therapy was initiated for maternal chorioamnionitis. This is critical because chorioamnionitis, an infection of the fetal membranes, increases the risk of neonatal sepsis due to GBS. The presence of maternal infection necessitates closer observation and management of the newborn, as the risk of transmission and subsequent infection in the neonate is heightened.

In this scenario, the initiation of antibiotics in the mother serves to mitigate these risks, but it also highlights the need for the newborn to be evaluated for signs of infection. Guidelines often recommend that newborns whose mothers are treated for chorioamnionitis be monitored and may receive antibiotics even if they are otherwise stable, as they are at an increased risk for developing early-onset sepsis.

The choice of other scenarios, such as antibiotic prophylaxis being given shortly before birth, being born prematurely, or prolonged rupture of membranes, may indicate a need for observation; however, they do not necessarily require the active initiation of antibiotic therapy unless accompanied by signs of infection or other risk factors. Therefore, option B aligns with clinical guidelines that prioritize the safety and health of the newborn in the context