Mansouri 2010

Methods	Type of study: double‐blind RCT Method of treatment allocation: not described Stratification: not stated Placebo: yes, placebo‐controlled Sample size calculation: not stated Intention‐to‐treat analyses: yes Losses to follow‐up: no Funding: not stated in translation Double‐blind, randomised controlled trial in Kurdistan University of Medical Sciences, Sanandaj, Iran
Participants	Location: Kurdistan University of Medical Sciences, Sanandaj, Iran Timeframe: "during 2007" stated Eligibility criteria: women at high risk of preterm labour, not described Gestational age range: 35‐36 weeks Exclusion criteria: not stated in our translation Total recruited: 200 women and 200 infants; 100 women and 100 infants in the treatment arm and 100 women and 100 infants in the control arm
Interventions	The treatment group received 2 doses of 12 mg betamethasone, IM. The control group received a placebo of normal saline.
Outcomes	Maternal outcome (maternal death, maternal infections), fetal/neonatal outcomes reported (RDS, birthweight, necrotising enterocolitis, systemic infection in the first 48 h of life, need for mechanical ventilation/CPAP, Apgar < 7 at 5 min, admission to NICU)
Notes	Original article in Persian; we have obtained a truncated translation for this update. Our translator was unable to translate the definition of respiratory distress syndrome but said that the outcome was based on defined symptoms and confirmed by a paediatrician. Additonal outcome data for this trial are: Maternal length of stay > 3 d (equal numbers in treatment arms) is reported narratively above: mean birthweight and SD in kg has been analysed as g. Data for the trial outcome of 'need for respiratory support' has been included in the review analysis 1.26 'need for mechanical ventilation'. We have been unable to confirm whether the trial included only singleton pregnancy, but this is suggested by the equal numbers of women and infants reported. We have included data from this trial in the singleton subgroup. We had no information about membrane status from our translation, and so this trial has been included in the 'not reported or mixed population subgroup.' Maternal length of stay > 3 d (equal numbers in both arms) is reported narratively. We emailed study investigators for clarification and additional information with no reply (2/2016).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Generation of sequence not stated, but block method specified
Allocation concealment (selection bias)	Unclear risk	Not stated
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Trial described as double‐blind. Placebo‐controlled trial, and researchers and women were blind to treatment
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Neonatal outcomes extracted by blinded paediatrician.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data reported for all women randomised
Selective reporting (reporting bias)	Low risk	Relevant outcome data reported
Other bias	Unclear risk	We have obtained a basic translation, but future correspondence with authors may clarify some of the risk of bias domains above.