Analysis of the proliferative phase uterine microenvironment and its potential contribution to idiopathic infertility in women FITZGERALDHARRIET CHRISTEL 2019 This thesis examined changes in the uterine environment of infertile women compared to fertile women during the proliferative phase of the menstrual cycle. The proliferative phase is when the lining of the uterus, the endometrium, regenerates following menstruation. Dysfunction in the development of the endometrium may create a hostile environment for pregnancy, rendering a woman infertile. This thesis identified distinct changes in the uterine environment of infertile women during this period of regeneration and highlights potential causes of infertility as well as possible therapeutic targets to treat infertility in women.