The round ligament of the uterus goes from the pelvis, passes through the internal abdominal ring, and runs along the inguinal canal to the labia majora.^[1] It is the structure that holds the uterus suspended inside the abdominal cavity.^[2] RLP is one of the most common discomforts of pregnancy^[3] and usually starts at the second trimester of gestation and continues until delivery.^{[citation needed]} It usually resolves completely after delivery although cases of postpartum RLP, e.g. RLP that persisted for a few days after delivery have been reported. RLP also occurs in non-pregnant women.

The most common symptoms of RLP are:

• Sudden pain in the lower abdomen, usually in the right side of the pelvic area that can extend to the groin.
• Shooting abdominal pain when performing sudden movements or physical exercise. Pain is sudden, intermittent and lasts only for a few seconds.^[6]

The pathogenesis of RLP is varied. Although very common during pregnancy, non-gestating women can also experience RLP. The most common causes of RLP are as follows:

• RLP may be caused by a spasm or cramp when the ligament contracts involuntarily. The ligament pulls on nerve fibers and sensitive structures of the female reproductive system. Since the uterus tends to be oriented towards the right side of the body, the pain is also often felt on the right side. This leads to frequent confusion with appendicitis.^[7]

• During pregnancy, the uterus expands to accommodate the growing fetus. This increase in size and weight of the uterus puts stress on the ligament that holds it, causing it to stretch. During physical exertion or sudden movements, the ligament is overly stretched, causing pain.
• Varicosities,^[8] e.g. enlargement of the blood vessels of the round ligament can occur during pregnancy, causing pain and swelling. The varicocoele starts at the veins draining the round ligament and the inguinal canal and is associated with engorgement of the veins of the ovaries and the pelvis during pregnancy.
• Endometriosis^[9][10] that infiltrates or borders the uterine round ligament can cause RLP in fertile, non-gestating women.
• Other pathologies that involve the uterine round ligament can cause RLP.

Abdominal pains during pregnancy may be due to various pathologies. RLP is one of the most common and benign of these pains. However, diagnosis of RLP is problematic. Some of the conditions that may present symptoms similar to those of RLP are appendicitis, ectopic pregnancy, kidney stones, urinary tract infection, uterine contractions, inguinal hernia, ovarian cysts, and endometriosis. If abdominal pain is continuous and accompanied by vaginal bleeding, excessive vaginal discharge, fever, chills, or vomiting, then it is most unlikely to be RLP and immediate consultation with a health care provider is warranted