Tehraninejad 2012.

Study characteristics
Methods	Study design: RCT Setting: Valiasr department of Imam Hospital complex Period: Patients enrolled from January 2010 to March 2011
Participants	94 couples eligible, 4 cases withdrew before randomisation, 4 cases randomly divided into only BT or SEHB groups. All cases in each group had high‐grade blastocysts Ιnclusion criteria: Infertility period of less than 10 years, more than four embryos available on day 2 in the oocyte retrieval cycle, and no previous history of ART cycles Exclusion criteria: age over 38 years for women, hydrosalpinx BT or stimulation (SEHB) groups 45 Baseline characteristics: SEHB group (45) Mean age of patients (years) 30.7 ± 5.9 Mean duration of infertility (years) 7.9 ± 5.2 Mean BMI (kg/m2) 26.1 ± 3.6 FSH level (mIU/mL) 6.2 ± 2.4 Mean number of oocytes fertilised 9.4 ± 4.2 Mean number of blastocysts transferred 1.9 ± 0.3 Mean endometrial thickness 9.9 ± 0.9 BT group (45) Mean age of patients (years) 31.7 ± 5.1 Mean duration of infertility (years) 8.1 ± 4.1 Mean BMI (kg/m2) 25.5 ± 2.5 FSH level (mIU/mL) 7.2 ± 2.2 Mean number of oocytes fertilised 9.1 ± 3.5 Mean number of blastocysts transferred 1.9 ± 0.1 Mean endometrial thickness 9.3 ± 1.9
Interventions	Stimulation of endometrium with high‐grade blastocyst culture supernatant perfusion before blastocyst transfer
Outcomes	Implantation rates, pregnancy rates, abortion, preterm and term delivery rates were compared between the two groups. Number of chemical pregnancies (%) Number of clinical pregnancies Implantation rate per embryo (%) Number of term deliveries Number of preterm deliveries Number of abortions A detectable gestational sac was considered as a characteristic of clinical pregnancy, and we calculated the implantation rate by dividing the number of gestational sacs by the number of embryos transferred to the uterine cavity. Abortion, preterm or term delivery, and multiple gestations were considered as pregnancy outcomes in both groups.
Notes	Two physicians categorized blastocysts as good or poor grade blastocysts, according to the criteria of Gardner et al.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Simple random allocation ‐ computer generated
Allocation concealment (selection bias)	Low risk	The computer generated random allocation to group I or group II was performed by a blinded technician, thus a third party was no further involved in the procedure
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Authors report that specialists who saw patients and did operations in each group were blinded to patient groups
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Incomplete ‐ there are concerns about altering results
Incomplete outcome data (attrition bias) All outcomes	Low risk	Authors report that 90 patients (45 in SEHB and 45 in BT only group) were followed up until pregnancy outcome was recorded
Selective reporting (reporting bias)	Unclear risk	Both primary and secondary outcomes including adverse events analysed adequately ‐ no registered protocol
Other bias	Low risk	Complete information of the contributors, support and conflict of interest was provided All patients were asked to fill in an informed consent form before procedure although the study had been approved by ethics committee of Tehran University of Medical Sciences (ID number: IRCT138902232576N2)