Azimi Nekoo 2015.

Methods	2‐arm, parallel RCT 2 ART centres
Participants	176 women undergoing FET Inclusion criteria: infertile women (male factor) aged 20‐37 years who had regular menstrual cycles and had previously undergone IVF or ICSI with the same induction protocol with embryo cryopreservation. Exclusion criteria: not reported Baseline characteristics were similar in the 2 groups
Interventions	HT (83 women) Women received oral estradiol valerate 4 mg/d from day 2‐day 5 and 6 mg/d from day 6 to the day of the pregnancy test. In day 13 of cycle, an US examination was performed. After US confirmation of endometrial thickness (8 mm) and no ovarian activity, progesterone suppository 800 mg/d was added. The dose of estradiol was increased to 8 mg/d if endometrial thickness was < 8 mm. 2 or 3 embryos were transferred via transcervical route 48 h after the beginning of progesterone administration. In addition to HT, steroid supplementation was commenced without prior pituitary suppression. HT plus GnRHa (93 women) In addition to HT, triptorelin 3.75 mg IM, as a depot GnRHa was administered in the mid‐luteal phase (day 21) of previous cycle.
Outcomes	Miscarriage rate per woman Clinical pregnancy rate per woman
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random sequence
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not reported but non‐blinding of outcome assessors may not have affected some of the outcome measures as they were objectively assessed
Incomplete outcome data (attrition bias) All outcomes	Low risk	All women randomized were included in data analysis
Selective reporting (reporting bias)	Unclear risk	Insufficient information to make a conclusive judgement
Other bias	Low risk	Baseline characteristics were similar in the 2 groups