El‐Zibdeh 2005.

Methods	Country carried out: Jordan. Date conducted: 1994‐2000. Type of trial design: RCT. Unit of randomisation: recurrent miscarriage. Method of randomisation: according to day of the week women attended clinic. Timing of randomisation: N/A. Number of centres: 1. Source of funding: N/A.
Participants	Total number randomised: 98. Total number for analysis: 98. Inclusions: at least 3 consecutive miscarriages with the same husband; no cause found for recurrent miscarriage after investigations. Exclusions: > 35 years.
Interventions	Treatment arm: IM hCG (Profasi, Serono; Pregnyl, Organon). 5000 IU every 4 days. Control arm: no treatment. Additional interventions: both arms received supportive care; multivitamins, bedrest, standard antenatal follow‐up. Duration: from diagnosis of pregnancy to 12 weeks.
Outcomes	Pregnancy loss. Threatened miscarriage. Obstetric complications. Delivery details. Congenital abnormalities. Neonatal death. Adverse effects.
Notes	This study assessed the efficacy of hCG versus dydrogesterone compared to a control group. Only the data pertaining to the hCG and control groups have been included here.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Women randomised on day of clinic attendance; quasi‐randomisation.
Allocation concealment (selection bias)	Unclear risk	Details of allocation concealment not stated in the study.
Incomplete outcome data (attrition bias) All outcomes	Low risk	All the patients randomised completed the study.
Selective reporting (reporting bias)	Unclear risk	No selective reporting apparent in the study.
Other bias	Low risk	No other bias apparent in the study.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Details of blinding methodology not stated in the study.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Details of blinding methodology not stated in the study.