Endometrium-related infertility: molecular and clinical insights

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.