Obidniak 2016.

Study characteristics
Methods	RCT Single centre Russia
Participants	Women undergoing frozen embryo transfer. Inclusion criteria: Female age 32 to 40 years RIF defined as at least 2 cycles of IVF in which good‐quality embryos (the Gardner blastocyst grading system) were transferred in each cycle without achieving a clinical pregnancy Exclusion criteria: Congenital uterine anomalies Asherman’s syndrome Endometrial thickness on the day of embryo transfer in previous cycles < 7 mm
Interventions	3 arms: Group 1 (N = 40): intrauterine perfusion with G‐CSF (filgrastim 30 mIU, 1 mL) using insemination catheter 5 days prior to embryo transfer (intervention arm) Group 2 (N = 30): G‐CSF (filgrastim 30 mIU, 1 mL) was administered subcutaneously once at the day of embryo transfer (intervention arm) Group 3 (N = 60): no therapy (control arm)
Outcomes	Implantation rates, clinical pregnancy rates
Notes	Conference abstract. No clinical registration number available. Authors could not be contacted. Doses of G‐CSF stated in the abstract to be 30 million IU; FDA information suggests dose of 300 mcg/mL which is equivalent to 30 milli‐international units (mIU); intervention text amended accordingly.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Three groups was formed on the basis of randomisation" Method of randomisation not mentioned.
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment not mentioned.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding of participants and personnel not mentioned. Assessed as high risk as the control arm had no placebo treatment or sham procedure.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Does not specify if outcome assessors were blinded. However, absence of blinding is unlikely to have influenced the findings for our primary and secondary outcomes, hence categorised as low risk for detection bias.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data for all participants were considered in the reporting of results.
Selective reporting (reporting bias)	Unclear risk	Insufficient information to permit a judgement
Other bias	Unclear risk	Insufficient information to permit a judgement