Polycystic Ovary Syndrome (PCOS) is a prevalent endocrine disorder affecting women of reproductive age, characterized by hormonal imbalances, insulin resistance, and polycystic ovaries. This review explores the multifaceted nature of PCOS and its impact on pregnancy, focusing on the complexities of hormonal and metabolic imbalances that impair endometrial receptivity and decidualization. Disrupted estrogen signaling, reduced integrity of endometrial epithelial tight junctions, and insulin resistance impair the window of endometrial receptivity. Progesterone resistance adversely affects decidualization. The review also examines the roles of various immune cells and inflammatory processes in the endometrium, contributing to reproductive challenges. Animal models, particularly those induced by hormonal interventions, offer insights into the syndrome's impact on pregnancy and potential treatments. Advanced understanding and treatment strategies are needed to address the reproductive complications associated with PCOS, emphasizing the intricate interplay of hormonal, metabolic, and immune factors.Polycystic Ovary Syndrome (PCOS) is a prevalent endocrine disorder affecting women of reproductive age, characterized by hormonal imbalances, insulin resistance, and polycystic ovaries. This review explores the multifaceted nature of PCOS and its impact on pregnancy, focusing on the complexities of hormonal and metabolic imbalances that impair endometrial receptivity and decidualization. Disrupted estrogen signaling, reduced integrity of endometrial epithelial tight junctions, and insulin resistance impair the window of endometrial receptivity. Progesterone resistance adversely affects decidualization. The review also examines the roles of various immune cells and inflammatory processes in the endometrium, contributing to reproductive challenges. Animal models, particularly those induced by hormonal interventions, offer insights into the syndrome's impact on pregnancy and potential treatments. Advanced understanding and treatment strategies are needed to address the reproductive complications associated with PCOS, emphasizing the intricate interplay of hormonal, metabolic, and immune factors.