Antenatal prevention of neonatal group B streptococcal infection

Group B streptococci can be isolated from the vagina of 15–40% of pregnant women. Vertical transmission to the infant occurs in 50% of deliveries involving colonised women. Most infants remain asymptomatic, but 1–2% develop clinical infection, which is associated with significant morbidity and mortality. Vertical transmission can be successfully prevented by intrapartum administration of antibiotics. Other proposed methods include vaccines and intrapartum vaginal or neonatal washing with antiseptics.Selection of women for prophylactic antibiotics can be based on risk factors, screening or a combination of both. Benefits of prophylaxis should be balanced against cost, medicalisation of labour and the risks of anaphylaxis and bacterial resistance.We present an overview of vaginal group B streptococcal isolation methods and antenatal strategies for prevention of neonatal infection.