MOLECULAR MARKERS OF ENDOMETRIAL RECEPTIVITY IN CLINICAL PRACTICE: POSSIBILITIES AND LIMITATIONS OF APPLICATION

Abstract

Endometrial receptivity is regarded as one of the key conditions for successful embryo implantation, especially in assisted reproductive technology programs. Even after the transfer of morphologically high-quality embryos, pregnancy does not always occur, which increases interest in evaluating the endometrium as an independent factor influencing reproductive outcomes. The formation of a receptive state is associated with the coordinated action of hormonal regulation, immune responses, cytokine signaling, gene expression, microRNAs, protein molecules, and the local microbiota. In this regard, molecular markers of receptivity are increasingly considered as a tool for clarifying the “window of implantation” and personalizing management strategies for patients with implantation failure. The aim of this review is to analyze the possibilities and limitations of using molecular markers of endometrial receptivity in clinical practice. The review considers the main groups of markers, including transcriptomic, proteomic, immunological, epigenetic, and microbiome indicators, as well as diagnostic approaches based on their assessment, including ERA and similar molecular tests. It is shown that these methods expand the understanding of the functional state of the endometrium and may be useful for individualized embryo transfer planning; however, their clinical significance remains a matter of debate. The limitations of their application include variability of results, dependence on the day of the cycle, the influence of hormonal protocols, inflammatory processes, and concomitant gynecological diseases, as well as insufficient standardization of data interpretation. It is concluded that molecular assessment of endometrial receptivity has potential for personalized reproductive medicine, but it cannot be considered a universal method for predicting implantation without taking into account the clinical context, embryo quality, and the patient’s condition.