Group B Streptococcus (GBS) in Pregnancy

GBS normal habitat

GI tract and vagina, where it causes no harm to the mother.

GBS transmission risk

Passes through the vagina to the baby during birth.

GBS maternal UTI

Occurs when GBS bacteria spread to the maternal urinary tract during pregnancy.

GBS antenatal swab timing

Vaginal and perianal swab performed at 35 to 37 weeks' gestation.

GBS treatment during pregnancy

No treatment required, unless GBS is found in the urine.

IV antibiotics in labor

Administered to the mother to prevent early-onset infection in the baby.

GBS prophylaxis for elective C-section

Not required, because the baby does not pass through the birth canal.

GBS finding 5+ weeks before labor

Unreliable; repeat swab at 35-37 weeks or treat as positive.

GBS in maternal urine

Requires immediate UTI treatment and IV antibiotics during labor.

Neonatal GBS infection rate (untreated)

Approximately 1% of babies exposed during vaginal birth will become unwell.

High maternal GBS colonization

Increases the overall likelihood of neonatal infection.

Premature babies GBS risk

Increased susceptibility to infection due to an immature immune response.

Neonatal GBS complications

Septicaemia, meningitis, and pneumonia.

Early-onset neonatal GBS

Presents 24 to 72 hours after birth.

Late-onset neonatal GBS

Presents 72 hours to 1 week after birth.

NZ GBS screening policy

A risk-based approach rather than universal screening.

NZ GBS risk factors for prophylaxis

GBS in urine, previous infected baby, PROM >18 hours, positive swab, preterm labor.