In the third trimester, your body makes room for the fetus. While doing so, it causes the stretching of ligaments around your womb. Round ligaments support the uterus, and when you stretch your body, extra strain is put on this ligament, which results in pain in the groin region. Another reason for groin pain is SPD, in which pelvic joints in front of the pelvis get weak to accommodate the baby and cause pain (2, 11).