Does a mother with Group B Streptococcus (GBS) positive status require antibiotics after a cesarean section (C-section) delivery?

From the Guidelines

A mother with Group B Streptococcus (GBS) positive status does not require additional antibiotics specifically for GBS after a cesarean section delivery, as the standard surgical prophylactic antibiotics administered before skin incision are sufficient to prevent surgical site infections and cover GBS. This is based on the guidelines from the Centers for Disease Control and Prevention (CDC) in 2010, which state that intrapartum antibiotic prophylaxis to prevent early-onset GBS disease is not recommended as a routine practice for cesarean deliveries performed before labor onset on women with intact amniotic membranes, regardless of the GBS colonization status of the woman or the gestational age of the pregnancy 1.

The standard surgical prophylactic antibiotics, usually cefazolin 2g IV for normal weight women, 3g for those >120kg, create adequate blood levels to prevent vertical transmission of GBS to the newborn, making additional GBS-specific antibiotics unnecessary. Key points to consider include:

• The use of perioperative prophylactic antibiotics to prevent infectious complications of cesarean delivery should not be altered or affected by GBS status 1.
• Women expected to undergo cesarean deliveries should undergo routine vaginal and rectal screening for GBS at 35–37 weeks’ gestation because onset of labor or rupture of membranes can occur before the planned cesarean delivery, and under those circumstances GBS-colonized women should receive intrapartum antibiotic prophylaxis 1.
• If the cesarean is performed after membrane rupture or labor has begun, the obstetrician may sometimes continue GBS prophylaxis alongside surgical antibiotics due to increased transmission risk during this period.

Overall, the administration of standard surgical prophylactic antibiotics before cesarean delivery provides adequate protection against GBS transmission, and additional antibiotics specifically for GBS are not typically required in this setting.

From the Research

Group B Streptococcus and Antibiotic Use in C-Section Deliveries

• A mother with Group B Streptococcus (GBS) positive status may require antibiotics after a cesarean section (C-section) delivery, depending on various factors such as the presence of other risk factors and the results of antibiotic susceptibility testing 2, 3, 4.
• The American College of Obstetricians and Gynecologists (ACOG) recommends intrapartum antibiotic prophylaxis for GBS positive patients, including those with penicillin allergies, to prevent neonatal sepsis 5.
• For women with penicillin allergies, alternative antibiotics such as cefazolin, clindamycin, and vancomycin may be used, depending on the severity of the allergy and the results of antibiotic susceptibility testing 3, 4, 5.
• The mode of delivery, including C-section, may also be a factor in determining the need for antibiotics, although the evidence is not conclusive 6.
• Studies have shown that intrapartum antibiotic prophylaxis can reduce the risk of early-onset neonatal GBS infection by 80-95% 2, 3.

Antibiotic Choices for GBS Positive Patients with Penicillin Allergies

• Cefazolin, vancomycin, and clindamycin are commonly used antibiotics for intrapartum neonatal sepsis prophylaxis in GBS positive patients with penicillin allergies 5.
• The choice of antibiotic should be based on the severity of the penicillin allergy, the results of antibiotic susceptibility testing, and current guidelines from organizations such as ACOG 3, 4, 5.
• Regular antibiotic susceptibility testing is important to ensure that the chosen antibiotic is effective against the GBS isolate 5.

Prevention of Neonatal GBS Infection

• Universal vaginal-rectal screening for GBS colonization is recommended between 36 and 37 weeks of gestation 4.
• Intrapartum antibiotic prophylaxis is recommended for individuals with positive GBS screens and other risk factors, such as preterm delivery, maternal fever during delivery, and membrane rupture more than 18 hours before delivery 2, 3, 4.
• The risk of early-onset neonatal GBS infection can be reduced by administering intravenous penicillin or alternative antibiotics, such as cefazolin, clindamycin, and vancomycin, during labor 2, 3, 4.