El‐Zibdeh 1998.

Methods	Randomised controlled trial.
Participants	114 women with a history of recurrent unexplained recurrent miscarriage. All women were under 35 years of age. The mean number of previous abortions was 3.3.
Interventions	48 women received progesterone therapy. 36 women received human chorionic gonadotrophin (5000 IU IM every 4 days). 30 women received no treatment. The interventions were stopped at 12 weeks of gestation.
Outcomes	In the human chorionic gonadotrophin group, 31 (81.5%) women achieved live births. In the no treatment arm, 20 (68%) of women achieved live births.
Notes	This study was presented in abstract form following a presentation at the 16th World Congress on Fertility and Sterility (1998). We have contacted the author for further information about the study and await their reply.