Faro 1990.

Methods	RCT. Individual women. 10‐arm study.
Participants	Inclusion criteria Women in labour giving birth by CS. Labour > 2 hours; afebrile. N = 1580. Exclusion criteria Antibiotics within previous 7 days.
Interventions	Interventions: cephalosporins (B1, B2, B3). Cefazolin (B1), 1 g x 3 doses (N = 142). Cefazolin (B1), 1 g (N = 217). Cefazolin (B1), 2 g (N = 161). Ceftizoxime (B3), 1 g (N = 145). Cefonicid (B2), 1 g (N = 147). Cefotetan (B2), 1 g (N = 148). Cefoxitin (B2), 1 g (N = 155). Cefoxitin (B2), 2 g (N = 162). Total N = 1277. Comparisons: penicillins (A3, A4). Ampicillin (A4), 2 g (N = 148). Piperacillin (A3), 4 g (N = 155). Total N = 303.
Outcomes	Endometritis (defined as temperature > 37.8 ºC x 2, 4 hours apart, excluding 24 hours after delivery plus tachycardia, white blood count > 14, uterine tenderness).
Notes	Dates: 7 December 1989 to 1 July 1989. Setting: Harris County Hospital, US. Mixed ethnic population. Subgroups Non‐elective CS. After cord clamping. IV administration. Mostly single dose, only 1 multiple dose. Comparisons 1 (subgroup 1); 2; 3; 4; 5; 6; 7; 8; 9; 10. Study reported as 'ongoing' and so randomisation was not complete and 1 group had a many more women than the others. This is likely to contribute to high risk of bias. No information on funding source of study.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“...randomised...according to a computer‐generated schedule.”
Allocation concealment (selection bias)	Unclear risk	No information provided.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Prospective, open, randomised study.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Prospective, open, randomised study but assessors may have been blinded.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No loss to follow‐up as yet but study still on‐going at time of publication.
Selective reporting (reporting bias)	Unclear risk	We did not assess trial protocol.
Other bias	Unclear risk	The difference in the numbers allocated to groups (ranging from 142 to 217) is reported as likely to be due to the study being on‐going and the randomisation schedule not complete or to some statistical issue, this si unclear. No information on funding source of study.