Methods	RCT; 3 parallel groups.
	Unit of randomization: individual.
Participants	Dates of data collection: September 1977-January 1978.
	Setting: State Maternity Hospital, Helsinki, Finland.
	Inclusion criteria: all women undergoing CS.
	Exclusion criteria: allergic to penicillin, clindamycin or gentamicin; emergency section
Interventions	10 million units benzyl penicillin IV (N = 46) vs 500 mg clindamycin IV and 80 mg gentamicin IM (N = 42) vs glucose solution placebo (N = 40) IV by infusion starting 30 minutes before operation and stopping 4 hours after. Results of both treatment groups combined
Outcomes	Endometritis (fever, uterine tenderness and foul-smelling vaginal discharge); wound infection (all grades combined); hospital stay (treatment 7.7 vs 7.7 placebo; no variance given)
Notes	Data from a fourth group that consisted ofpatients allergic to 1 ofthe drugs or undergoing an emergency section have not been included
	Drug class: penicillin or lincosamide (clindamycin) and aminoglycoside
	Subgroups: type of CS unclear; before cord clamping.
Risk of bias
Item	Authors’ judgement	Description
Adequate sequence generation?	Unclear	“Assigned at random … in bottles containing code numbers.”
		No further information provided.
Allocation concealment?	Unclear	No information provided.
Blinding?	Yes	Placebo-controlled.
All outcomes		“the code was kept secret for persons performing the operations and observing the patients in the post-operative period.”
Incomplete outcome data addressed?	Unclear	No loss to follow up reported.
All outcomes		Two women excluded after initial randomization.
		ITT analysis with available data.
Free of selective reporting?	Unclear	Insufficient information to judge.
Free of other bias?	Unclear	The first 3 groups were comparable regarding number of amnioscopic examinations, number of vaginal examination, duration of labor and duration of intrauterine monitoring. There was insufficient other information which to judge
Overall low risk of bias?	Unclear	Mostly unclear.