El‐Zibdeh 2009.

Methods	Design: quasi‐experimental Recruitment method: pregnant women consecutively presented to the clinic during study period Method of randomisation: according to the day of the week the women attended the clinic; women attending on Saturday, Monday, and Wednesday were assigned to intervention group and those attending on Sunday, Tuesday, and Thursday were assigned to the control group Setting: Amman Islamic Hospital clinic
Participants	Inclusion: women with threatened miscarriage (mild or moderate vaginal bleeding during the first trimester of pregnancy) Exclusion: presence of a systemic illness or fever, the suspected passage of any fetal or pregnancy materials, and the absence of a normal gestational sac at 5 weeks gestational age, a yolk sac at 5.5–6 weeks gestational age, an embryo at 6–6.5 weeks gestational age or cardiac activity at 7 weeks gestational age Particpants randomised: 146
Interventions	Intervention group: (86 women) synthetic progesterone, dydrogesterone, oral 10 mg twice daily. Until 1 week after the bleeding stopped. Standard supportive care, including iron, folic acid and multivitamin supplements and bed rest Control group: (60 women) no treatment. Standard supportive care, including iron, folic acid and multivitamin supplements and bed rest
Outcomes	Miscarriage Preterm delivery Fetal structural malformations, including genital malformations Maternal hypertension Intra‐uterine growth restriction APH
Notes	Journal: Maturitas Year of publication: 2009 Country: Jordan Income status of the country: lower‐middle‐income Source of funding: Solvay Pharmaceuticals Conflict of interest: no actual or potential conflict
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	According to the day of the week the women presented to the clinic. Women attending the clinic on Saturday, Monday or Wednesday were allocated to the intervention group and those attending on Sunday, Tuesday or Thursday were allocated to the control group.
Allocation concealment (selection bias)	High risk	The randomisation was performed by the attending physician, who also gave the treatment to the women.
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding of the participants and study personnel
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinding was ensured for the outcome assessors.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss to follow‐up
Selective reporting (reporting bias)	Low risk	All the prespecified outcomes were addressed.
Other bias	High risk	The difference in the number of participants recruited to experimental and the control groups (86 versus 60) might have introduced bias.