Ovalle‐Salas 1997.

Methods	Randomised double‐blind, placebo‐controlled trial. No comment as to method of randomisation.
Participants	88 women. Inclusions: women with PPROM 24‐34 weeks, PPROM diagnosed with sterile speculum‐pooling, ferning and nitrazine tests. No digital examination performed. Exclusions: labour, significant haemorrhage, abruptio placentae, use of antibiotics within 30 days before screening for study, fetal anomaly or death, multiple gestation, documented allergy to clindamycin or gentamicin, uterine abnormality, presence of IUCD, fetal distress, clinical chorioamnionitis, maternal medical complications necessitating delivery or any condition precluding expectant management and intrauterine growth retardation (< 10th centile for gestational age).
Interventions	Clindamycin 600 mg IV every 6 hours for 48 hours + 4 mg/kg/day gentamycin IV for 48 hours followed by Clindamycin 300 mg orally every 6 hours for 5 days + gentamycin 2 mg/kg/day IM every 12 hours for 5 days. Matching placebo.
Outcomes	Prolongation of pregnancy, maternal infection related morbidity, birthweight, neonatal morbidity and admission to neonatal intensive care unit.
Notes	November 1990‐September 1994. 3 sites: 2 Chile, 1 USA. Women had infection screen. 88 women randomised (treatment 42, control 46). 1 lost to follow‐up in placebo arm. Trial stopped after intermediate evaluation showed treatment group had better outcome.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information given.
Allocation concealment (selection bias)	Unclear risk	No information given.
Blinding (performance bias and detection bias) All outcomes	Low risk	Stated as double‐blind trial.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data appear complete with 1 loss to follow‐up.
Selective reporting (reporting bias)	Unclear risk	Protocol not available.
Other bias	High risk	Trial stopped after intermediate evaluation showed treatment group had better outcome.