Rudge 2006.

Study characteristics
Methods	RCT. Individual women. 3‐arm study.
Participants	Inclusion criteria Women due for CS. N = 600, however only 400 women included in this review (remaining 200 received no antibiotic prophylaxis) Exclusion criteria Urinary or pulmonary complications Infections justifying use of antibiotics Fever Use of antimicrobial agents in past 15 days Events requiring use of other antimicrobial agents before randomisation.
Interventions	Intervention 1: 1st generation cephalosporin (C1) Cephalothin 2 g, IV, single intraoperative dose given soon after cord clamping· Total number randomised: N = 200 Intervention 2: natural penicillins(standard at hospital). Benzathine penicillin (P1) + procaine penicillin (P1) Benzathine penicillin 1,200,000IU given IM + procaine penicillin 400,000 IU given IM given every 12 hours during 1st 48 hours Unclear from trial report when first dose given, however report implies that this is standard scheme and that all drugs were given postoperatively.  Total number randomised: N = 200 Comparator: no antibiotics ‐ data not used in this review No antibiotics. Total number randomised: N = 200 Subgroups Type of CS: unclear No primary outcome data for subgroup analyses Comparisons: 4
Outcomes	Puerperal infection; wound infection; post CS infection; costs of antibiotics.
Notes	Dates of study: March 1994 to July 1996. Setting: Unversity Teaching Hospital, Botucata School of Medicine, Sao Paulo State University, UNESP, Brazil. 1500 births annually. Funding sources: not reported. Declarations of interest: not reported. Additional information Costs: the authors provide brief information on cost of interventions which we report narratively in our results. "In Brazil a penicillin scheme costs US$ 1.17 per patient and a cephalothin US$ 1.0 per patient", The authors conclude that "prophylactic cephalothin use was associated with decreased puerperal infection and presented a cost benefit".
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Computer generated random numbers".
Allocation concealment (selection bias)	Unclear risk	Quote: "Sealed envelopes".
Blinding of participants and personnel (performance bias) All outcomes	High risk	No information provided and routes of administration are different so likely the clinicians knew.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: “the outcome observers were not informed about which group the patients had been allocated to”
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss to follow‐up.
Selective reporting (reporting bias)	Unclear risk	Pre‐specified outcomes only were reported but we did not assess trial protocol.
Other bias	Unclear risk	Baseline characteristics similar. ITT analysis. Too little methodological information to assess if other biases.