Vidal 2019.

Methods	RCT
Participants	Women without recurrent implantation failure receiving donor eggs
Interventions	Study group: endometrial scratching by pipelle biopsy in the luteal phase of the menstrual cycle prior to the embryo transfer Control group: no procedure
Outcomes	Ongoing pregnancy, clinical pregnancy, multiple pregnancy, miscarriage
Notes	Trial registration: NCT01955356 (registered Oct 2013, registered prospectively) Study is available as interim analyses only, therefore study is pending the publication of the full text. Correspondence undertaken with Carmina Vidal, Carmina.vidal@ivirma.com