Nelson 1985

Methods	Type of study: RCT Method of treatment allocation: random‐number table generated randomisation sequence with consecutive sealed envelopes used. Stratification: none stated Placebo: no Sample size calculation: no Intention‐to‐treat analyses: yes Losses to follow‐up: no Funding: not stated
Participants	Location: Wake Forest University Medical Center, North Carolina, USA Timeframe: not stated in manuscript, the study is coded as 1980s for the review Eligibility criteria: women with PROM Gestational age range: 28 and 34 weeks Exclusion criteria: fetal distress, active labour, cervical dilatation > 3 cm, sensitivity to tocolytics, PROM > 24 h, existing infection Total recruited: 44 women and infants; 22 women and infants in each arm
Interventions	3 treatment arms. Group 1, 2 doses of 6 mg or 12 mg betamethasone IM 12 h apart, delivery 24‐48 h after PROM and after 24 h of corticosteroid therapy. Group 2, delivery 24‐48 h after PROM. Group 3, expectant management. We did not include Group 3 in the review.
Outcomes	Fetal/neonatal outcomes (neonatal death, RDS, proven neonatal infection while in NICU) and health service outcome reported (length of neonatal hospitalisation)
Notes	Authors provided further information
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random‐number table generated randomisation sequence
Allocation concealment (selection bias)	Unclear risk	Consecutive sealed envelopes were used, not stated if opaque
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding of participants and personnel was not possible due to the nature of the comparison.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Blinding of outcome assessment was not described.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No losses to follow‐up or exclusions
Selective reporting (reporting bias)	Low risk	Study protocol not available, but appears to report on all pre‐specified outcomes
Other bias	Unclear risk	Insufficient information to asses if other sources of bias exist.