Bourgeois 1985.

Methods	RCT; 3 parallel groups. Unit of randomization: individual.
Participants	Dates of data collection: initiated March 1981. Setting: Charlottesville, Virginia, USA, almost all were indigent women. Inclusion criteria: both 'low risk' (labor < 6 hrs) and 'high risk' (> 6 hrs) women undergoing CS. N = 148 for this comparison. Exclusion criteria: allergy to penicillin or cephalosporin; antibiotic use within 7 days; antibiotics required for other reasons; pyrexia > 38oC; foul amniotic fluid.
Interventions	Intervention: cefamandole, 2 g in 1000 mL normal saline; irrigation of the uterus and peritoneal cavity; N = 73. Comparison 1: placebo: saline placebo; N = 75. Comparison 2: no treatment: no irrigation group; N = 44. As the objective of this review is to compare antibiotic with no antibiotic, rather than the effect of irrigation, only the 1st 2 groups are compared (double‐blind comparison).
Outcomes	Metritis (pyrexia > 38oC twice 8 hrs apart, after 24 hrs plus abnormal uterine tenderness, without another apparent source); duration of maternal stay (treatment 5.29 days vs placebo 6.32 days, variance could not be calculated).
Notes	Authors' definition of low and high risk do not correspond to those used for elective/non‐elective in this review. No treated patients developed evidence of drug reaction. There were no serious infections (pelvic abscess or phlebitis) in either group. Class of antibiotic: 2nd generation cephalosporin. Subgroup: both elective and non elective; after cord clamping. The groups were comparable regarding gravidity, parity, maternal weight, hematocrit, etc.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "A computer generated table of random numbers".
Allocation concealment (selection bias)	Low risk	Quote: "Assigned under the direction of the hospital pharmacy".
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: no loss to follow‐up reported; no participants excluded; ITT analysis.
Selective reporting (reporting bias)	Unclear risk	Comment: insufficient information to judge.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Comment: partially double‐blind placebo‐controlled (3 groups: antibiotic irrigation, saline placebo irrigation, no irrigation). Physicians were unaware of the type of irrigation used.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Comment: probably outcome assessment was blinded.
Other bias	Low risk	Comment: no other sources of bias identified.