Lenke 1983.

Methods	RCT.
Participants	Number of pregnant women randomised: 200. Inclusion criteria Pregnant. Admitted for pyelonephritis: CVA tenderness and in addition 2 of the following 3 criteria (1) temperature of ≥ 101oF, (2) pyuria (≥ 5 white blood cells per high power field) or (3) bacteriuria (presence of any motile rods per high power field). Exclusion criteria Prior history of pyelonephritis during the index pregnancy. Patients who delivered during the acute phase of pyelonephritis. Setting: Los Angeles, USA. Period: October 1979 ‐ May 1981. Definitions Recurrent UTI: significant dysuria or frequency in absence of fever or CVA tenderness. Recurrent pyelonephritis: CVA tenderness and in addition 2 of the following 3 criteria (1) temperature of ≥ 101oF, (2) pyuria (≥ 5 white blood cells per high power field) or (3) bacteriuria (presence of any motile rods per high power field). Positive culture: gram‐negative organisms (≥103 colonies per mL) with growth of no more than 1 other organism. Negative culture: no growth or < 103 gram‐negative organisms per mL. Contaminated culture: gram‐negative organisms present ≥103 per mL) with concomitant growth of at least 2 other organisms.
Interventions	Intervention group (n = 100): Nitrofurantoin 50 mg orally, 3 times daily, for the remainder of the pregnancy plus close surveillance. Control group (n = 100): close surveillance only. ALL WOMEN Follow‐up (close surveillance): all patients were followed in the special clinic every 2 weeks until the 36 weeks when they were seen weekly until delivery. At each visit a clean‐catch, mid voided urine was obtained for a routine culture and nitrite testing. When culture results were positive, attempts were made to reach patients to schedule a return appointment within 1 week. Treatment: irrespective of group, patients received a short course of antibiotics in clinic under 3 circumstances: if the patient’s last culture (on suppression in the treated group) was positive; if the nitrite test was positive; if the patient developed clinical symptoms of a UTI.
Outcomes	Maternal Recurrent UTI. Recurrent pyelonephritis. Culture results. Voluntary abortions. Spontaneous abortions. Clinic attendance > 90%. Asymptomatic bacteriuria (ASB) in > 90% attendance group. Infants Premature birth (< 37 weeks). Birthweight (g). Birthweight ≤ 2500 (g). 5‐minute Apgar score < 7. 1‐minute Apgar score < 7. Placental weight (g). Head circumference (cm). Body length (cm). Post mature (> 42 weeks).
Notes	Funding: supported in part by Ariel Kaare Rosholt Weathers‐Lowin Medical Research Foundation and National Institute of Health grant HD07086‐05. Table shows birthweight ≥ 2500 (g). We think this should be < 2500 (g) and have entered it accordingly.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Random number tables."
Allocation concealment (selection bias)	Unclear risk	Not reported.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Participant: no blinding. Clinician: no blinding. Describe: “the control group received no pills” “ the doctors responsible for patient care were aware of whether the patient was in the treated or control group”.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Low for culture results. Low for pregnancy outcomes.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Lost to follow‐up: 18/100 nitrofurantoin and close surveillance group; 15/100 close surveillance group. No reasons given.
Selective reporting (reporting bias)	High risk	Overall, very few pregnancy outcomes were measured. "observation period ended at the time of delivery, as logistics prevented longer follow‐up".
Other bias	Low risk	No major baseline differences.

CVA: costovertebral angle
 mL: millilitre
 RCT: randomised controlled trials
 UTI: urinary tract infection