After rupture of membranes during labor, which antibiotic prophylaxis is commonly used?

• A. No antibiotics
• B. Oral amoxicillin
• C. IV cefazolin with possible azithromycin
• D. IV vancomycin

Answer: (C)

During labor with rupture of membranes, giving antibiotics intrapartum helps prevent neonatal infection from Group B Streptococcus transmitted from the birth canal. The goal is to have adequate antibiotic levels in the mother (and thus in the fetus) at the time of delivery.

A cephalosporin given IV, such as cefazolin, is a common backup if penicillin cannot be used, especially when the allergy is not severe (no anaphylaxis). In settings where coverage for additional sexually transmitted pathogens is considered, an azithromycin may be added. Vancomycin is reserved for cases of severe penicillin allergy or suspected resistant organisms, not routine prophylaxis. Oral amoxicillin isn’t used for intrapartum prophylaxis because reliable drug levels during labor are not guaranteed, and no antibiotics would leave the newborn at higher risk.

So, IV cefazolin with possible azithromycin represents a practical intrapartum prophylaxis approach after rupture of membranes to reduce neonatal infection risk.