Brumfitt 1975.

Methods	Placebo‐controlled; 2 parallel groups
Participants	Inclusion criteria: 'significant' bacteriuria (clean‐catch urine) at first antenatal visit and 7 to 10 days later; microbiological criteria not stated Setting: London and Birmingham, UK
Interventions	Sulphonamide (sulphormethoxine 2 g single dose) vs placebo (see Williams 1968 for description of treatment regimen)
Outcomes	Low birthweight (< 2500 g); mean birthweight, mean gestational age Pyelonephritis (loin pain, fever or rigours; fever of at least 100 °F; > 100,000 bacteria/mL)
Notes	Outcome of low birthweight (N = 425) Outcome of pyelonephritis in placebo group (55/179) Outcome of pyelonephritis reported for subset of treated women (N = 87): 0/45 successful treatment after 1 course, 4/22 successful after 2 courses; failed (persistent infection) 5/20. Data on persistent bacteriuria provided for treatment group only Outcome reported for women who developed anaemia during pregnancy (haemoglobin 10.2 g/100 mL or less at 32 weeks): 16.8% treated vs 25.9% placebo, P < 0.01 There is no explanation for the difference in numbers in the placebo group (reported as 179 for the outcome of pyelonephritis and 178 for other outcomes), nor the total number of participants, in any reports of this study. Dates of study: 1967 to 1968 (estimated) Funding sources: Board of Governors of the United Birmingham Hospitals and the Birmingham Regional Hospital Board Declarations of interest: none reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	The investigators do not describe the sequence generation process: "... were originally assigned to the placebo group ..." There is no description of how women were assigned to treatment or placebo. There is no explanation for the unequal numbers in the treatment and placebo groups.
Allocation concealment (selection bias)	Unclear risk	No information provided to judge
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	"... were given placebo under double‐blind conditions". Method not described in sufficient detail.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	"... were given placebo under double‐blind conditions". Method not described in sufficient detail.
Incomplete outcome data (attrition bias) All outcomes	High risk	Inconsistencies in total number of women not explained (number of < 2500 g babies provided for 413/426 bacteriuric women); results not provided for outcome of pyelonephritis for all women in treated group
Selective reporting (reporting bias)	High risk	Results not provided for outcome of pyelonephritis for all women allocated to treatment.
Other bias	Low risk	The study appears to be free of other sources of bias.
Overall Risk of Bias	Unclear risk	Unclear overall