Watts 1989.

Methods	Randomized trial Study period: February 1980 through February 1983
Participants	Inclusion criteria: patients with early postpartum endometritis with elevated temperature (≥ 38.5 °C); abdominal pain; abdominal, uterine and adnexal tenderness and no other apparent source of fever outside of the genital tract Setting: University of Washington Hospital, Seattle, Washington, USA
Interventions	Intravenous beta‐lactam (n not stated) vs clindamycin‐gentamicin (n not stated)
Outcomes	Presence of bacteria and site of isolation
Notes	This study did not address the effect of antibiotic regimen in reference to treatment failure, rather it focused on the isolated microbes as well as associated complications
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method not stated, but not likely to change microbial isolate
Allocation concealment (selection bias)	Unclear risk	Method not stated, but not likely to change microbial isolate
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double blinding noted, but not likely to change outcome
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	No drop‐outs noted
Selective reporting (reporting bias)	Unclear risk	Not all outcomes are prespecified in the materials and methods section, although this would not have an effect on this systematic review as the outcomes are not consistent with other studies
Other bias	Unclear risk	Not clear

IM: intramuscular
 iv: intravenous
 SD: standard deviation
 vs: versus