Methods	Random allocation is presumed although method not described.
Participants	Dates of data collection: August 1972 to February 1973.
	Setting: University of Pennsylvania.
	Inclusion criteria: women undergoing CS.
	Exclusion criteria: penicillin allergy, fever in labor.
Interventions	Ampicillin 1 g and kanamycin 0.5 g IM 15 to 30 minutes before, and at 2 and 8 hours after delivery (N = 34) vs placebo (N = 34)
Outcomes	Endometritis (fever and uterine tenderness or fever and pathogenic organism without other cause); UTI; wound infection (fever, cellulitis and exudate; any grade); morbidity [fever > 100°F in two separate 24 hour periods after first postpartum day or positive post-operative urine culture of > 100,000 colonies/ml] (treatment 8/34 vs placebo 22/34)
Notes	1 pelvic abscess in placebo group.
	Authors’ definitions of repeat and primary section not comparable to those used for elective/non-elective in this review, categorized as ‘both’
	Class of antibiotic: aminopenicillin (ampicillin), aminoglycoside
	Subgroups: type of CS unclear; before cord clamping.
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Unclear	“Randomization of patients is acceptable.”
		Random allocation of patients is assumed but method not described
Allocation concealment?	Unclear	Insufficient details provided.
Blinding?	Yes	Placebo-controlled; study described as double-blind.
All outcomes		“The materials were prepared by the pharmacy service in coded identical vials, containing identically appearing solutions.” No specific statement to confirm adequate blinding of study personnel
Incomplete outcome data addressed?	No	“25 patients were eliminated because of penicillin allergy, fever in labor, errors in giving the medication, etc. None was used as a control.”
All outcomes		An ITT analysis was not performed and the data cannot be re-included
Free of selective reporting?	Unclear	Insufficient information to judge.
Free of other bias?	Unclear	“Randomization of patients is acceptable”.
		The groups were comparable regarding age, rupture of membranes, indication for CS and anemia
		Insufficient other information to judge.
Overall low risk of bias?	No	There is uncertainty around the sequence generation ad concealment allocation, and the high loss of data (25/68 = 37%) would suggest high risk of bias