Burman 1992.

Methods	Multi‐centre randomized, double‐blind, placebo‐controlled study. I. Blinding of randomization ‐ yes. II. Blinding of intervention ‐ yes. III. Complete follow‐up ‐ yes. IV. Blinding of outcome measurement(s) ‐ yes.
Participants	797 women of at least 37 weeks' gestation colonized with GBS and their term neonates. Exclusion criteria: Preterm deliveries, planned C/S, pregnancy complications after the 30th week of gestation requiring hospital admission, twin or multiple pregnancies, suspected fetal congenital malformations, known or suspected allergy to chlorhexidine, previous birth of an infant with GBS infection, antibiotics during the two weeks before admission, and antepartum fetal death. The trial took place at 10 Swedish hospitals. Study period not stated.
Interventions	388 women were treated with 0.2% diacetate chlorhexidine solution vaginal wash. 409 women were treated with placebo (sterile saline) vaginal wash. Each flushing of the vagina was with 60 mL of solution contained in 2 x 30 mL plastic ampoules that were attached to a 20 cm plastic catheter. Applicatiopn was started on arrival in the delivery room and repeated every 6 h until delivery. Women were considered treated if at least 1 hour passed between the first flushing and delivery and if no more than 6 h had passed between applications or between the last application and delivery.
Outcomes	1 infant with early‐onset GBS infection in the treatment group and 1 in the placebo group. No infants with GBS pneumonia in the treatment group and 1 in the placebo group. No infant with GBS meningitis in the treatment group and 1 in the placebo group. The one infant with meningitis in the placebo group had sepsis too. 3 women in the treatment group reported adverse effects (2 women reported slight vaginal stinging after 2 flushings, and 1 reported local irritation for 2 hours after 5 chlorhexidine flushings). No adverse effects were observed among infants.
Notes	Colonization rates were not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Women were assigned randomly to receive chlorhexidine or placebo according to a predefined block (25:25) allocation scheme."
Allocation concealment (selection bias)	Unclear risk	"Women were assigned randomly to receive chlorhexidine or placebo according to a predefined block (25:25) allocation scheme."
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	It is unclear if mothers and healthcare providers were blinded to group assignment. However, the study is announced as a prospective, randomized, double‐blind, placebo‐controlled study.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	1 neonatologist (N.W.S.) made the final decision on infants' diagnoses from their charts before breaking the treatment code.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Outcomes reported for all randomized mothers and their infants.
Selective reporting (reporting bias)	Unclear risk	The protocol for this study was not available to us so we cannot judge if there were any deviations from the protocol in the execution and reporting of the trial.
Other bias	Low risk	Appears free of other bias.