Ismail 2017.

Methods	Unit of randomization: pregnancy Method of randomization: computer‐generated tables Timing of randomization: before trying to conceive Power calculation: yes, needed 350 in each arm Blinding: yes (double) Number of centers: 1 ‐ Recurrent Miscarriage Clinic of Assiut Women's Health Hospital 700 women randomized, 675 women analyzed Source of funding: not stated
Participants	All women who presented to the clinic, "regular marital life with the same partner". Not specifically stated the inclusion criteria or definition of recurrent miscarriage but assumed it is similar to others based on other text as at least 3 unexplained miscarriages. Exclusion: known cause of recurrent miscarriage, antiphospholipid antibody syndrome, consanguinity Age: 20‐39 Location: Egypt
Interventions	400 mg progesterone pessary suppositories twice daily Control: matched placebo pessaries manufactured to look identical Treatment began immediately after documentation of ovulation using ultrasound. Continued until 28 weeks of gestation. Stopped if did not become pregnant that cycle ‐ allowed up to 6 cycles
Outcomes	Miscarriage rate (primary), viable pregnancy > 20 weeks, live birth rate, vaginal bleeding, preterm delivery, cytokine levels
Notes	Dates of study: September 2012‐November 2015 Funding sources: NIHR‐HTA, UK Declarations of interest: the trial authors reported "no conflicts of interest". This study will remain in awaiting classification pending clarification regarding the study data. Since publication of the 2018 update of this review, we have been advised that the Ismail 2017 study is currently the subject of an investigation by the Journal of Maternal‐Fetal & Neonatal Medicine. Consequently, we have now moved this study from 'included studies' to 'studies awaiting classification' until the outcome of the investigation is known.