Methods	Random allocation is presumed although method not described.
Participants	Dates of data collection: November 1971 and April 1972.
	Setting: University of Pennsylvania.
	Inclusion criteria: women undergoing primary CS or repeat section
	Exclusion criteria: penicillin allergy, fever in labor.
Interventions	Ampicillin 1 g, methicillin 1 g and kanamycin 0.5 g IM 15-30 minutes before, and at 2 and 8 hours after delivery (N = 33) vs placebo (N = 28)
Outcomes	Endometritis (fever and uterine tenderness or fever and pathogenic organism without other cause); UTI; wound infection (fever, cellulitis and exudate); morbidity [fever > 100 °F in 2 separate 24 hour periods after first postpartum day or positive post-operative urine culture of > 100,000 colonies/ml] (treatment 9/33 vs placebo 17/28); UTI (fever and urinary tract symptoms or a single significant culture with or without fever); maternal hospital stay (6.5 vs 6.9 days; no variance given)
Notes	2 serious infections: 1 pelvic abscess in treatment group, 1 septicemia in placebo group.
	Authors’ definitions of repeat and primary section not consistent with those used for elective/non-elective in this review
	Class of antibiotic: aminopenicillin (ampicillin), penicillinase-resistant penicillin (me- thicillin), aminoglycoside
	Subgroups: type of CS unclear; before cord clamping.
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Unclear	“…the patient randomization.”
		Random allocation is presumed although 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	No loss of participants to follow up.
All outcomes		17 patients “were eliminated from the study, 6 for errors in giving the study medications, 5 for penicillin allergies, 3 for fever in labor, 2 for being started on ampicillin prophylaxis, and 1 for cesarean hysterectomy”
		Analysis done on included patients; no data available to incorporate data on patients eliminated
Free of selective reporting?	Unclear	Insufficient information to judge.
Free of other bias?	Unclear	“The patient randomization is statistically acceptable.”
		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 (17/61 = 28%) would suggest high risk of bias