Attawattanakul 2015.

Study characteristics
Methods	Type of study: open‐label RCT Method of treatment allocation: method of randomisation not stated. Block randomisation used Stratification: none stated Placebo: no, comparison was no treatment Sample size calculation: "Sample size was calculated to have type one error of 5 per cent and 80 per cent power to detect a reduction of 50 per cent in rate of respiratory distress. Rate of respiratory distress in late preterm infant was assumed to be 28.9 percent based on Wang ML, et al. Accordingly, the number of study population was at least 95 pregnant women in each group." Intention‐to‐treat analyses: yes Losses to follow‐up: no
Participants	Location: Chonburi Hospital, Thailand Eligibility criteria: all pregnant women with singleton pregnancy admitted in labour (defined as "regular uterine contraction at least 4 times in 20 minutes or 8 times in 60 minutes and cervical dilatation more than 1 cm and cervical effacement at least 80 percent") with a gestational age of 34 weeks + 0 days to 36 weeks + 6 days Gestational age range: 34 weeks + 0 days to 36 weeks + 6 days Exclusion criteria: "Participants who had history of corticosteroid administration in current pregnancy, history of dexamethasone allergy, systemic infection, multifetal pregnancy, complicated pregnancy including overt diabetes mellitus, gestational diabetes mellitus (GDM), pregnancy induced hypertension (PIH), placenta previa and abruptio placentae, positive or unknown sexual transmitted disease serology, PROM, evidence of fetal amniotic membrane leakage confirmed by two of the following test; pooling, nitrazine test, fern test or cough test, known fetal intrauterine restriction, oligohydramnios, non‐reassuring fetal heart rate tracing, fetal death, fetal anomaly, suspicious of chorioamnionitis (fetal tachycardia >160/min, maternal fever > 37.8°C, uterine tenderness, foul smelling amniotic fluid), cervical dilatation more than 7 cm, were excluded from our study." Total recruited: 194 women and infants; 96 women and infants in the treatment arm and 98 women and infants in the control arm.
Interventions	The treatment group received 6 mg dexamethasone IM, up to 4 doses 12 hours apart. The control group received no treatment.
Outcomes	Maternal outcomes (chorioamnionitis, side effects of therapy in women) Fetal/neonatal outcomes (RDS, IVH, birthweight, necrotising enterocolitis, systemic infection in the first 48 hours of life, need for mechanical ventilation/CPAP, Apgar score < 7, admission to NICU)
Notes	Labour augmentation performed if needed even if women had not received full course of steroids. 6 (6%) women in the intervention group received a full course of steroids; most women (75/96 (78%)) in the intervention arm received just 1 dose of dexamethasone. Data for 'maternal local or systemic adverse reactions to treatment' have been included in the review under our outcome of maternal side effects. Data from the trial are available for the following outcomes: low birthweight (not defined); hypoglycaemia in infant; need for respiratory support in infant (6/96 treatment and 14/98 control; (these data are in addition to the need for 'positive pressure ventilation' included in the review outcome 'need for mechanical ventilation'); and maternal length of stay (not separated into intrapartum and postpartum) Contact details: 3803 Qiss Bldg. A2 5,6Fl. Room 501‐2,601‐2 Rama IV Rd., Phra Khanong, Khlong Toei, Bangkok ‐ 10110 Email: info@takaraivfbkk.com Information from trialist (received July 2020): "The protocol was developed and approved by our IRB committee prior to the enrolment. This trial prospectively register at Chonburi hospital but do not have online registration number." Dates of the study: March 2013‐March 2014 Funding sources: not stated Declarations of interest: authors declare no competing interests
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported. Method reported as block randomisation only
Allocation concealment (selection bias)	Unclear risk	Not stated
Blinding of participants and personnel (performance bias) All outcomes	High risk	Open‐label, participants would have been aware of allocation. Delivery nurse not blinded but all other hospital staff delivering care were blind
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	The data were retrieved from chart review and hospital staff were blinded apart from delivery room nurses.
Incomplete outcome data (attrition bias) All outcomes	Low risk	5 women in the dexamethasone delivered after 1 week and were included in ITT analysis
Selective reporting (reporting bias)	Low risk	Relevant outcome data reported
Other bias	Low risk	The groups were comparable at baseline.