Mulla 1960.

Methods	Randomised trial, 2 parallel groups
Participants	Inclusion: bacteriuria at 30 to 32 weeks; microbiological criteria not stated Setting: Ohio, USA Number of participants: N = 100
Interventions	Sulfadimethoxine 250 mg twice a day x 7 days, repeated if bacteriuria persisted (N = 50) vs no treatment (N = 50)
Outcomes	Pyelonephritis (criteria for diagnosis not given; described as "acute symptoms of cystopyelitis").
Notes	Half (13/26) infections developed postpartum; only antepartum infections included in analysis No side effects necessitating discontinuation of treatment Dates of study: not stated Funding sources: not stated Declarations of interest: none reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No description of sequence generation process
Allocation concealment (selection bias)	Unclear risk	Women were "randomly divided into two groups"; no other details provided
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not placebo‐controlled
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information provided to judge whether outcome assessment was blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing outcome data
Selective reporting (reporting bias)	High risk	No definition for outcome of "cystopyelitis"; no pregnancy outcomes (gestational age, birthweight)
Other bias	Low risk	The study appears to be free of other sources of bias.
Overall Risk of Bias	Unclear risk	Judged at overall high risk of bias.