Adenomyosis is a benign condition characterized by the presence of endometrial glands and stroma with the myometrium.It not only impairs fertility but also significantly increases the risk of adverse pregnancy outcomes. By disrupting the integrity of the endometrial-myometrial junction and inducing chronic inflammation and fibrotic remodeling, adenomyosis exerts multidimensional effects on embryo implantation, placental development, and uterine contractile function. In early pregnancy, adenomyosis may impair endometrial receptivity and alter the local immune microenvironment, thereby significantly increasing the risk of pregnancy loss. During the second and third trimesters, uterine structural abnormalities and sustained inflammatory activation contribute to higher rates of preterm birth, placental abnormalities and hypertensive disorders of pregnancy, particularly in women with diffuse adenomyosis. During labor and the postpartum period, impaired myometrial contractility and placental complications further increase the risks of postpartum hemorrhage and adverse neonatal outcomes. This review systematically summarizes the associations between adenomyosis and adverse pregnancy outcomes and highlights the need to recognize adenomyosis as a high-risk pregnancy condition, which requires stratified risk assessment systems, dynamic monitoring and individualized management to improve maternal and neonatal outcomes.