ISRCTN24605402.

Study name	Effect of endometrial scratch on repeat implantation failure following in vitro fertilization embryo transfer or frozen embryo transfer
Methods	RCT
Participants	Patients with repeated implantation failure (two or more) undergoing in vitro fertilisation embryo transfer (IVF‐ET) or frozen embryo transfer (FET)
Interventions	Intervention: endometrial scratch was offered on day of observation of Luteinizing hormone (LH) + 7 immediately prior to commencement of IVF treatment Control: no procedure
Outcomes	Clinical pregnancy
Starting date	16 January 2013
Contact information	Prof Zhang Songying: zhangsongying @126.com, zhangsongying@zju.edu.cn
Notes	Trial registration status on 3 July 2020: no longer recruiting Author correspondence attempted but unsuccessful