Heitmann 1989

Methods	Selected by randomisation table to receive treatment or no treatment; not blinded or placebo‐controlled.
Participants	393 women undergoing instrumental deliveries (either vacuum or forceps deliveries). Women were excluded if they had evidence of chorioamnionitis, or other infections, or if they were allergic to penicillin or cephalosporins. Setting: University Hospital of Jacksonville, USA; September 1986 to February 1988.
Interventions	2 g of cefotetan intravenously after cord clamping (n = 192) or no treatment (n = 201).
Outcomes	Endomyometritis (at least 1 rise in oral temperature greater than 38.1 degrees Celsius after the first 24 hours of delivery and uterine tenderness or foul‐smelling lochia with no clinical or laboratory evidence confirming another source of the fever).
Notes	Dates study conducted: the trial was carried out between September 1986 and February 1989. Funding sources for the study: the funding sources of an included study could not be identified. Declarations of interest among primary researchers: not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	A randomisation table was used for random sequence generation.
Allocation concealment (selection bias)	Unclear risk	Allocation concealment could not be interpreted.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Information not clearly mentioned.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Who measured the outcome was not mentioned.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Same number of samples at intervention given and outcome measure.
Selective reporting (reporting bias)	Unclear risk	The study protocol was not available, so there was insufficient information to permit judgement.
Other bias	Low risk	Study appeared to be free of other sources of bias.