Methods	Double blind, RCT; 3 parallel groups.
	Unit of randomization: individual.
Participants	Date of data collection: March 1985 - August 1986.
	Setting: Mexico.
	Inclusion criteria: women undergoing CS (labor < 12 hours, membrane rupture < 12 hours, < 7 vaginal exams)
	Exclusion: any antibiotic within 2 weeks, fever, clinical evidence of infection
Interventions	Ampicillin 1 g IV every six hours × 3 then 1 g every 6 hours × 7 days (N = 23) vs ampicillin 1 g every 6 hours × 3 doses then placebo (N = 37) vs placebo (N = 31). Antibiotics administered after surgery, within 2 hours of the procedure
Outcomes	Fever > 38 °C × 2 at least 6 hours apart after first 24 hours; endometritis (temperature > 38 °C, purulent lochia, pain on internal examination); wound infection (increased warmth, size or colour of wound, or purulent secretions); urine infection (dysuria and positive culture)
Notes	Paper was not written in English.
	No explanation provided for unequal size groups.
	Class of antibiotic: Aminopenicillin (ampicillin).
	Subgroups: type of CS unclear; after cord clamping.
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Yes	“…by computerized tables…”
Allocation concealment?	Unclear	Assignment to treatment group was performed using the computer card which is attached to the file
		No additional information was provided.
Blinding?	Yes	Double-blind.matching placebo doses.
All outcomes
Incomplete outcome data addressed?	Unclear	3 were lost to follow up 3 patients excluded for inadequate follow up (group allocation not provided).and no exclusions were reported. The analysis was ITT with the available data
All outcomes
Free of selective reporting?	Unclear	Insufficient information to judge.
Free of other bias?	Unclear	No information provided on which to make a judgement.
Overall low risk of bias?	No	Allocation concealment is unclear and no explanation provided for unequal size groups and no explanation provided for unequal size groups