Group B streptococcus screening and prophylaxis

Maternal colonization with group B streptococcus (GBS) is the most significant risk factor for early-onset neonatal GBS infections.

Prenatal screening for GBS

Indications

Routine screening for all women from 36+0 to 37+6 weeks' gestation, regardless of planned delivery method
- in order to guide management if unexpected early labor or rupture of membranes occurs.

Method of collection

Swab the lower vagina and introitus, followed by the rectum.

Prophylaxis for neonatal GBS infection

Indications for GBS prophylaxis

History of early-onset GBS infection in a previous newborn
Documented GBS colonization during the current pregnancy, i.e.:
- Positive GBS culture
- GBS bacteriuria
Unknown GBS status in current pregnancy PLUS any of the following are present:
- Any maternal risk factors for neonatal early-onset GBS infection
  - Imminent preterm delivery < 37+0 weeks' gestation or PPROM
  - Prolonged rupture of membranes (i.e., > 18 hours)
  - Maternal temperature ≥ 100.4 °F (38.0 °C)
- Positive intrapartum NAAT
- Positive GBS status confirmed via culture or bacteriuria in a previous pregnancy

Tip

Regardless of GBS culture results, intrapartum antibiotic prophylaxis for neonatal GBS is not needed if cesarean delivery is performed prior to the onset of labor and with intact membranes.

Antibiotic regimens

Antibiotics should ideally be initiated at least 4 hours prior to delivery.

No penicillin reaction: IV β-lactam antibiotics, i.e., IV penicillin G (off-label) OR IV ampicillin (off-label)