Prevention of excess neonatal morbidity associated with group B streptococci by vaginal chlorhexidine disinfection during labour

Abstract Streptococcus agalactiae transmitted to infants from the vagina during birth is an important cause of invasive neonatal infection. We have done a prospective, randomised, double-blind, placebo-controlled, multi-centre study of chlorhexidine prophylaxis to prevent neonatal disease due to vaginal transmission of S agalactiae. On arrival in the delivery room, swabs were taken for culture from the vaginas of 4483 women who were expecting a full-term single birth. Vaginal flushing was then done with either 60 ml chlorhexidine diacetate (2 g/l) (2238 women) or saline placebo (2245) and this procedure was repeated every 6 h until delivery. The rate of admission of babies to special-care neonatal units within 48 h of delivery was the primary end point. For babies born to placebo-treated women, maternal carriage of S agalactiae was associated with a significant increase in the rate of admission compared with non-colonised mothers (5·4 vs 2·4%; RR 2·31, 95% Cl 1·39-3·86; p=0·002). Chlorhexidine reduced the admission rate for infants born of carrier mothers to 2·8% (RR 1·95, 95% Cl 0·94-4·03), and for infants born to all mothers to 2·0% (RR 1·48, 95% Cl 1·01-2·16; p=0·04). Maternal S agalactiae colonisation is associated with excess early neonatal morbidity, apparently related to aspiration of the organism, that can be reduced with chlorhexidine disinfection of the vagina during labour.