Endometrium-related infertility: molecular and clinical insights

Abstract

Infertility, defined as the failure to achieve an ultrasound-confirmed pregnancy after regular unprotected sexual intercourse for at least 12 months, affects an estimated 186 million couples worldwide, bringing with it substantial physical, emotional and financial challenges. The causes of infertility are often complex and multifactorial. In up to 50% of couples seeking help for infertility, no clear cause is found, leading to a diagnosis of unexplained or idiopathic infertility. A pregnancy starts with successful embryo implantation, a delicate process requiring a viable blastocyst, a receptive endometrium and a synchronised interaction between the two. The endometrium, the inner lining of the uterus, plays a crucial role in reproduction, and alterations in its function have been proposed as potential causes of unexplained infertility. The studies in this thesis aimed to characterise the endometrium of infertile and fertile women at the molecular level using various approaches, such as the analysis of the endometrial transcriptome and microbiota, and the development of endometrial organoids. Furthermore, the efficacy of endometrial scratching as a clinical strategy to address endometrial-related infertility was investigated in couples with unexplained infertility.