Methods	Randomized placebo-controlled trial; 2 parallel groups.
	Unit of randomization: individual.
Participants	Dates of data collection: not reported.
	Setting: Jeddah, Saudi Arabia.
	Inclusion criteria: women undergoing CS (both elective and emergency)
	Exclusions: use of antibiotics, fever or signs of infection; allergy to penicillin or cephalosporin
Interventions	Cefazolin 1 g after clamping of the cord (N = 221) vs matching placebo (N = 220)
Outcomes	Febrile morbidity (> 38°C twice 4 hours apart after first 24 hours); endometritis (fever, uterine tenderness and abnormal lochia); wound infection (fever, cellulitis or exudate with positive culture); UTI (fever and positive urine culture); pneumonia, bacteraemia, pelvic abscess, unexplained fever, therapeutic antibiotics, length of post-operative stay
Notes	Definition of emergency section (unscheduled) did not correspond to the definition of non-elective section used in this review; these patients have been analysed in the “both or not-defined” group. Women undergoing elective section included women with scheduled section and with intact membranes and have been analysed in the “elective” group.
	There were no significant differences in the fetal outcomes reported (definitions not consistent with those for this review; no serious side effects with cefazolin
	Class of antibiotic: first generation cephalosporin.
	Subgroups: both elective and non-elective CS - data separated by elective and non-elective; after cord clamping.
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Yes	“…computer-generated randomization…”
Allocation concealment?	Yes	“…each indistinguishable minibag was given a code number in the department of pharmaceutical care.” There was, however, no information on how the codes were used and whether there was sequential opening
Blinding?	Yes	Triple blind. “Both the experimental drug and placebo were indistinguishable.”
All outcomes
Incomplete outcome data addressed?	Yes	No losses or exclusions were reported. Analysis appeared to be by ITT
All outcomes
Free of selective reporting?	Unclear	Insufficient information to judge.
Free of other bias?	Unclear	The 2 groups were comparable regarding maternal characteristics and emergency and elective CS. Insufficient information overall
Overall low risk of bias?	Yes	Mostly low risk of bias.