NCT01202643.

Study characteristics
Methods	RCT Single centre USA
Participants	Female IVF patients aged between 21 and 45 years who were willing to be randomised to treatment and, in either IVF treatment, FET or donor IVF cycles, 5 days before ET, and have inadequate endometrial thickness (< 7 mm). Exclusion criteria: Sickle cell disease Renal insufficiency Upper respiratory infection or pneumonia Chronic neutropenia Known past or present malignancy
Interventions	Intervention group (N = 6): G‐CSF 300 mcg/mL administered by transcervical infusion 1 time on day of hCG trigger for ovulation Control group (N = 6): normal saline administered by transcervical infusion 1 time on day of hCG trigger for ovulation 1 cm3 Only data from phase 1 were included (pre‐cross‐over), which were fresh transfers.
Outcomes	Clinical pregnancy rates, implantation rates, endometrial thickness
Notes	Trial was terminated prematurely. Data were available on trial registry site. Authors responded and provided clarification regarding study details. Study was not published.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “Computer generated randomisation table with 50:50 distributions”
Allocation concealment (selection bias)	Unclear risk	No information on method of allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Participant, care provider, investigator, outcome assessor were blinded.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Participant, care provider, investigator, outcome assessor were blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	All randomised participants completed phase 1 of the trial. We only included data from phase 1 in the meta‐analysis (pre‐cross‐over).
Selective reporting (reporting bias)	Low risk	Data for all prespecified outcomes were reported.
Other bias	High risk	The trial was terminated prematurely before the calculated sample size could be achieved due to insufficient recruitment. The trial was not peer reviewed/published.