Update of recent studies of adenomyosis-associated dysmenorrhea

Adenomyosis is characterized by invasion of endometrial glands and stromal cells into the myometrium. It is a common gynecological disorder that usually occurs in women during their reproductive years. The primary clinical manifestations of adenomyosis are menorrhagia and progressive dysmenorrhea. The pathogenesis of adenomyosis-associated dysmenorrhea is complicated. However, it is predicted that oxytocin, inflammatory factors, and prostaglandin F2α are responsible for adenomyosis-associated dysmenorrhea via the induction of uterine smooth muscle contractions. Additionally, the pain conductivity of the pelvic viscera (internal organs) involves both the sympathetic (T10-L1) and parasympathetic (S2-4) nervous systems located in the abdominal region. This article provides a review of the pathophysiology of dysmenorrhea in adenomyosis and the nociceptive afferent pathway of the pelvic splanchnic nerves.