Yassaee 2014.

Methods	Design: RCT Recruitment method: through assessment of women presented to the hospital Method of randomisation: unclear Setting: Taleghani Hospital affiliated to Shahid Beheshti University of Medical Sciences
Participants	Inclusion: pregnant women with threatened abortion. The presence of singleton pregnancy and detection of fetal heart activity, besides gestational age of < 20 weeks was verified by U/S Exclusion: women were excluded if they had reaction to Cyclogest, repeated abortions, multiple gestation, absence of fetus or fetal heart tone, uterine anomaly or fetal anomaly Particpants randomised: 60 women
Interventions	Intervention group: 400 mg of vaginal progesterone suppository (Cyclogest) each day until their bleeding stopped in < 1 week Control group: no treatment
Outcomes	Successful delivery Miscarriage rates Pain relief
Notes	Journal: Journal of Reproduction and Infertility Year of publication: 2014 Country: Iran Income status of the country: upper middle‐income Source of funding: not mentioned Conflict of interest: no conflicts
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details on random allocation
Allocation concealment (selection bias)	Unclear risk	Unclear
Blinding of participants and personnel (performance bias) All outcomes	High risk	There was no placebo, so participants were not blind
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Assessors were blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss of participants to follow‐up
Selective reporting (reporting bias)	Low risk	All the prespecified outcomes were addressed
Other bias	Low risk	No apparent other risk of bias

APH: antepartum haemorrhage; LBW: low birthweight; RCT: randomised controlled trial; U/S: ultrasound