round ligament

The round ligament originates at the uterine cornu (anterolateral to the fallopian tube insertion), travels through the deep inguinal ring, traverses the inguinal canal, and terminates by blending into the connective tissue of the labia majora. It is accompanied by the artery of Sampson (a branch of the uterine artery) within the broad ligament. Embryologically, it develops from the gubernaculum, analogous to the gubernaculum testis in males, reflecting the common origin of the female and male genital ridges. Functionally, it helps maintain the uterus in an anteverted, anteflexed position, though it provides relatively weak structural support compared to the cardinal and uterosacral ligaments, which are the primary support structures of the uterus. Clinically, round ligament pain is common in the second trimester of pregnancy due to stretching of the ligament as the uterus enlarges, typically presenting as sharp or dull pain in the lower abdomen/groin exacerbated by sudden movements. Surgically, the round ligament is often encountered and ligated during hysterectomy. A rare but notable clinical association is the Nuck canal cyst, formed from a patent processus vaginalis along the round ligament (the female analog of a hydrocele), which can present as a labial or inguinal mass. The round ligament is a key landmark in laparoscopic pelvic surgery and inguinal hernia repair in females, where indirect hernias occur through the same canal as the round ligament.