ABSTRACT
Intentional endometrial injury, also referred to as "endometrial scratching", prior to in vitro fertilization (IVF) treatment is one among many adjuvant methods designed to enhance implantation. This chapter clarifies the current knowledge regarding the underlying biological mechanisms of injury on the endometrium and discusses the clinical data in favor of and against such a procedure. Different theories by which endometrial injury may interact with implantation have been proposed, with data deriving from animal models, in vitro tissue culture, or clinical observations. Among the different reports, there is a large variability on the time of endometrial injury. The evidence of effectiveness and safety of endometrial injury in assisted reproductive technology (ART) procedures has been addressed in several systematic reviews and meta-analyses. A retrospective study by Dain in patients with previous implantation failure described the effect of local endometrial injury in the luteal phase of the previous menstrual cycle or in week 1 or 2 preceding ovum donation.
