Wu 1991.

Methods	Randomized into 3 groups (irrigation vs systemic treatment vs no treatment).
Participants	Dates of data collection: May 1988 to August 1989. Setting: Beijing, China. Inclusion criteria: women undergoing both elective (N = 112) and non‐elective (N = 105) CS. Only women undergoing an elective CS were randomized to treatment or no treatment and have been included in analysis. N = 112.
Interventions	Intervention: ampicillin 6 g after delivery of the placenta, local irrigation; N = 39. Intervention: combination [penicillin + aminoglycoside]: penicillin 5.6 MU and gentamicin 240,000 U IV immediately after surgery and penicillin 1.6 MU and gentamicin 160,000 U per day IM x 3 days; N = 41. Comparison: no treatment: no treatment; N = 32. Placebo data were divided: 1/2 for comparison with penicillin (A) and 1/2 for comparisons with the combined drug regimen.
Outcomes	Endometritis (presence of any 2 of following: temperature above 37.5oC, uterine tenderness, foul vaginal discharge); abdominal wound infection (cellulitis with small amount of exudate within 2 months of operation); uterine incision infection (associated with late postpartum hemorrhage); fever index.
Notes	Women undergoing non‐elective sections randomized to either treatment group (not included in this review). Class of antibiotic: amminoglycoside‐containing combination (natural penicillin and gentamicin) or aminopenicillin (ampicillin). Subgroups: elective CS; after cord clamping.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "...randomized..". Comment: no description of sequence generation process.
Allocation concealment (selection bias)	Unclear risk	Comment: no information provided.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: no losses or exclusions were reported. Analysis appears to be ITT.
Selective reporting (reporting bias)	Unclear risk	Comment: insufficient information to judge.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comment: no blinding, not placebo‐controlled.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Comment: probably outcome assessment was not blinded.
Other bias	Low risk	Comment: no other sources of bias identified.