What Are the Common Causes of an Enlarged Uterus?

Uterine enlargement can occur among women of various ages. The common causes of an enlarged uterus could be physiological, gynecological, or malignant. The most common physiological cause is pregnancy. Gynecological causes include uterine pathologies such as uterine fibroids and adenomyosis. Malignant causes of an enlarged uterus include uterine cancer and metastases.

Pregnancy is the primary consideration when a woman of childbearing age complains of uterine enlargement associated with cessation of menses. The uterus reaches the pubis at 3 months, the umbilicus or navel at 4.5 months, and the xiphoid or the lowermost part of the sternal bone at 9 months. The associated symptoms of an enlarged uterus due to pregnancy include morning sickness and breast tenderness.

Uterine fibroids are also among the most common causes of an enlarged uterus. They are the most common pelvic tumors and affect about 70% of women when they reach 45 years of age. A uterine fibroid, also called a leiomyoma, forms due to the proliferation of smooth muscle cells. Fibroids are benign growths and may be located in the mucosa, within the uterine muscle, or in the external walls of the uterus or serosa. The associated symptoms include irregular menstruation, excessive menstrual bleeding, acute or chronic pelvic pain, and infertility.

A disorder called adenomyosis, wherein endometrial tissue implants in the uterine wall, can lead to a large and inflamed uterus. Up to 20% of women suffer from this condition. The uterus is usually uniformly enlarged. Other symptoms include irregular and excessive menses, dysmenorrhea, and pain during coitus or dyspareunia.

Uterine cancer is also a common cause of uterine enlargement. Carcinomas and sarcomas can occur in the uterus, producing generalized enlargement of the organ. Aside from causing an enlarged and unhealthy uterus, uterine cancer can also cause symptoms of pelvic pressure, pelvic pain, and postmenopausal bleeding. Approximately 10% of postmenopausal women who complain of an enlarged uterus and vaginal bleeding are eventually diagnosed with endometrial cancer.

Before treating an enlarged uterus, the cause has to be determined. Gynecological examination and ultrasound testing are the primary methods of identifying the possible causes of an enlarged uterus. If pregnancy is the cause, supportive advice is given. For uterine fibroid or adenomyosis patients, hormone analogues may be given or surgical procedures, such as myomectomy or hysterectomy, may be recommended. If the suspected cause is uterine cancer, endometrial biopsy is performed and total hysterectomy with bilateral salpingo-oophorectomy is advised.