Sonographic assessment of endometrial receptivity in women during preparation for cryo-embryo transfer

Abstract

In modern reproductive medicine, against the backdrop of a global decline in fertility and the trend toward delayed motherhood, cryo-embryo transfer (CET) has become the "gold standard" of treatment. The transition from "fresh" cycles to cryo-protocols, which currently account for up to 77% of all assisted reproductive technologies (ART) cycles, is driven by the implementation of high-efficiency vitrification, the possibility of preimplantation genetic testing, and the near-total elimination of the risk of ovarian hyperstimulation syndrome. However, the success of the procedure critically depends on the synchronization between embryo readiness and endometrial receptivity.

Aim - to systematize ultrasound monitoring algorithms during preparation for CET within ART programs.

The article is devoted to the systematization of ultrasound monitoring algorithms as the primary tool for verifying the "implantation window." It analyzes patient preparation strategies within three main scenarios: natural cycle: focused on maximum physiological compatibility and utilizing the woman's own endocrine resources; hormone replacement therapy: the method of choice for patients with anovulation, providing clear control over endometrial proliferation and transfer timing; stimulated cycle: an alternative approach for cases of endometrial resistance. Special attention is paid to sonographic phenomena that predict successful implantation.

Conclusions. Ultrasound monitoring is an indispensable navigation method in CET cycles. Strict adherence to temporal deadlines (baseline assessment on days 2-3, proliferation control on days 9-10, and luteinization monitoring) allows not only for an increased pregnancy rate but also ensures a personalized approach to each patient, neutralizing risks associated with premature endometrial transformation or an "asynchronous window".

The authors declare no conflict of interest.