From conception to delivery, a woman's uterus can grow from the size of a pear to the size of a watermelon. But pregnancy isn't the only potential reason for an enlarged uterus. An enlarged uterus is common and can be a symptom of a variety of medical conditions, some of which require treatment.
Uterine fibroids. Uterine fibroids are common noncancerous tumors of the muscular wall of the uterus, affecting as many as eight in 10 women by the age of 50. Fibroids more commonly affect women over age 30. They are also more common in African-Americans than Caucasians. Overweight and obese women also have a greater risk of developing fibroids. Hormonal and genetic factors contribute to their growth.
While some fibroids are very small, others grow to weigh several pounds. A woman may have a single fibroid or multiple fibroids. In addition to an enlarged uterus, symptoms of uterine fibroids may include:
Feeling of fullness or pressure in the lower abdomen
Heavy, painful, and/or long-lasting periods, sometimes with the passage of blood clots
If symptoms are severe, treatment may involve a procedure called uterine artery embolization to cut off the blood supply to the fibroids so that they shrink and eventually die, or surgery to remove the fibroids (myomectomy) or the entire uterus (hysterectomy). Other treatments include endometrial ablation. This procedure is performed for small submucusal fibroids (when the inside lining of the uterus is removed, burned or frozen) and laparoscopic myolysis (when freezing or an electric current is used to destroy the fibroids). Medications to help control painful periods or for pain may also be used. Other treatment options include focused ultrasound surgery and an intrauterine device (IUD) to decrease bleeding.
The cause of fibroids is not known, but the tumors seem to rely on estrogen to grow. After menopause, they often shrink naturally and cause no symptoms.
Adenomyosis. Adenomyosis is a diffuse thickening of the uterus that occurs when the tissue that normally lines the uterus (endometrium) moves into its muscular outer wall and behaves like the endometrium. When this happens in a small area, or is localized, it is called an adenomyoma.