Endometrial scratching (ES) for IUI is worthy of consideration because it may reduce the need for IVF while adding little inconvenience, discomfort, and cost.
Despite the increasing application of preimplanation genetic testing to ensure transferring euploid embryos, as well as freeze-all cycles to improve embryo–endometrial synchrony, implantation remains the rate-limiting factor for success with IVF. Endometrial scratching (ES), also referred to as endometrial injury, trauma, or biopsy, is a quick, minimally invasive office procedure with minor discomfort. It has been performed using a hysteroscope or a variety of soft and rigid endometrial biopsy devices.
There are several hypotheses proposing a mechanism of action for improving endometrial receptivity (successful implantation of the baby) with scratching. One hypothesis is that it facilitates endometrial decidualization. Another is that the injury leads to healing, with activation of an immune response with growth factors. A third hypothesis is that it slows endometrial maturation to improve synchrony.