Graham 1993.

Methods	RCT. Individual women. Multi‐centre. 2‐arm study.
Participants	Inclusion criteria Women who were in labour or had ruptured membranes and were about to have an indicated CS (repeat procedure, malpresentation, arrest of the active phase of labour). N = 84. Exclusion criteria Women who had received antibiotics within 7 days of the CS or who had a diagnosis of intra‐amniotic infection.
Interventions	Intervention: cephalosporin (B1). Cefazolin. 1 g; IV; after cord clamped. N = unclear. Comparison: penicillin (A4). Ampicillin. 2 g; IV; after cord clamped. N = unclear.
Outcomes	Genital tract cultures.
Notes	Setting: University Medical Centre, Lubbock & LBJ General Hospital, Houston, Texas, US. Subgroups Non‐elective CS. After cord clamping. IV administration. Single dose. No information about funding source of study. The study did not provide any data on the outcomes in the review. It assessed eradication of rates using before and after data.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"...computer‐generated number..."
Allocation concealment (selection bias)	Unclear risk	No information provided.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Antibiotic administration was not blinded.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Antibiotic administration was not blinded but outcome assessor could have been blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No exclusions of women were reported.
Selective reporting (reporting bias)	Unclear risk	We did not asses trial protocol.
Other bias	Unclear risk	Baseline characteristics across groups not reported and other aspects of possible bias unclear. No information about funding source of study.