Rehu 1980.

Methods	RCT. Individual women. 4 groups.
Participants	Inclusion Women undergoing CS in labour. N = 130 but only include 90 in this review as remainder given placebo. Exclusion None stated.
Interventions	Intervention 1: penicillin (A1). Benzyl penicillin (A1) 10x106 units in 1000 mlLof 5% glucose IV. N = 48. Intervention 2: lincosamide antibiotic (H) + aminoglycoside (G). Clindamicin (H) (500 mg in 1000 ml of 5% glucose IV) + gentamicin (G) (80 mg IM). N = 42. Comparison 1: placebo 1 (not included in this review). 100 mL 5% glucose without antibiotics. N = 40. Comparison 2: placebo 2 (not included in this review). 100 mL 5% glucose without antibiotics. N = 17.
Outcomes	Endometritis; wound infection; duration of hospital stay; number of women receiving post‐operative treatment.
Notes	Dates: September 1977 and January 1978. Setting: State/maternity hospital, Helsinki, Finland. Subgroups Non‐elective CS. Before cord clamping. IV administration. Multiple dose IV + IM) vs single dose and continued until 4 hours after operation. Comparison 13. Study compared a penicillin (benzyl penicillin) vs a macrolide (clindamycin) plus a aminoglycoside (gentamicin). Solutions of benzyl penicillin and clindamycin were infused starting 30 minutes prior to CS and the gentamicin was given by IM injection 30 minutes prior to the procedure. No information about funding source of study.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"...assigned at random...".
Allocation concealment (selection bias)	Unclear risk	Antibiotic preparations for intravenous use were supplied in solution in bottles carrying code numbers. Still unclear if there was allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"The code was kept secret for persons performing the operations and observing the patients in the postoperative period."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	"The code was kept secret for persons performing the operations and observing the patients in the postoperative period".
Incomplete outcome data (attrition bias) All outcomes	Low risk	Two out of the 147 women receiving antibiotics of other reasons during the preoperative period were later excluded from the series.
Selective reporting (reporting bias)	Unclear risk	We did not assess the trial protocol.
Other bias	Unclear risk	There was no information on baseline characteristics of the women in the groups, and other possible biases were unclear. No information about funding source of study.