Uterine adenomyosis is a condition in which the uterine lining grows into the muscle walls of a woman’s uterus. This may lead to heavy menstrual periods, pelvic pain, discomfort during sex, and other symptoms.  

The condition is most likely to affect women between the ages of 35 and 50, especially those who have carried two or more pregnancies to term. However, it is possible for younger women to experience uterine adenomyosis, including those who are trying to get pregnant for the first time. Though it is unusual, even teenagers may be affected. Women who have experienced miscarriage or had an abortion may also be at increased risk.  

When a woman has uterine adenomyosis, her uterus often grows significantly in size, sometimes becoming two or three times larger than it was before.  

Treatments, including medication and surgical procedures, may ease uncomfortable symptoms. Hysterectomy, a permanent solution, may eliminate pain and heavy menstrual bleeding, but this is not appropriate for everyone, especially those who wish to retain the option of childbearing.

“Adenomyosis can be treated medically or surgically, including but not limited to oral progesterone and levonorgestrel-releasing intrauterine devices [IUDs] such as Mirena,” says Yale Medicine gynecologic surgeon Farinaz Seifi, MD. “Surgical approaches include focal resection of adenomyosis to hysterectomy.”

Uterine adenomyosis is a condition in which the lining of the uterus grows into the walls of the uterus. It may cause pain and heavy bleeding during menstrual periods.  

In healthy women of childbearing age, the uterine lining builds up inside the uterus. If conception does not occur, the lining sheds each month during menstruation, and a new lining builds up the following month.  

When a woman has uterine adenomyosis, the uterine lining infiltrates the muscle walls of the uterus, typically causing pain and other symptoms.

Doctors aren’t sure exactly what causes uterine adenomyosis. However, evidence suggests that prolonged exposure to estrogen may be a contributing factor. Women may be exposed to more estrogen if their menstrual cycles are shorter than average or if they have been pregnant two or more times. Exposure to other hormones, including progesterone, prolactin, and follicle-stimulating hormone (FSH), and/or a history of uterine surgery, may also lead to the condition.

Women with uterine adenomyosis may experience the following symptoms:

• Menstrual bleeding that lasts significantly longer than usual
• Heavy menstrual bleeding
• Painful menstrual periods that become more painful over time
• Pelvic pain
• Pain during intercourse
• Infertility
• Pressure on the bladder or rectum
• Anemia

Women may be more likely to have uterine adenomyosis if they:

• Are between the ages of 35 and 50
• Have been pregnant two or more times
• Have had a Cesarean section
• Have had other uterine surgery, including dilation and curettage (for miscarriage or abortion)
• Have endometriosis
• Have fibroids
• Began getting menstrual periods at age 10 or earlier
• Have had shorter-than-usual menstrual cycles (for example, 24 days instead of 28 days)
• have been diagnosed with infertility
• Are obese Have taken birth control pills

Doctors may diagnose uterine adenomyosis after obtaining a patient’s medical history, performing a physical exam, and ordering diagnostic imaging tests.  

When a woman in her 40s reports one or more of the above-mentioned symptoms, including heavy menstrual bleeding and pain during sex, her doctor will want to know more about her reproductive history—whether she has been pregnant, miscarried, or had a previous abortion. Information about the menstrual cycle is also important—when it begins, how frequently it occurs, how heavy the flow is, and whether it’s accompanied by pain or other symptoms. A history of fibroids or endometriosis may also be relevant. 

During a physical exam, the doctor will look for signs of an enlarged uterus. In some women, the uterine may also be more sensitive to the touch.  

Imaging studies, including a transvaginal ultrasound or an MRI, may be used to diagnose the condition. These can reveal the presence of abnormal tissue growth in the uterus, suggesting uterine adenomyosis.  

Doctors may also use a hysteroscope—a lighted tool that functions a bit like a telescope—to look for the presence of uterine adenomyosis. Doctors insert this thin tool into the uterus through the vagina.

Doctors may offer women one or more of the following medications to reduce symptoms of uterine adenomyosis:

• Non-steroidal anti-inflammatory drugs (NSAIDs), which may soothe menstrual cramps.
• Birth control pills, may lighten menstrual flow and can also help reduce discomfort.
• Hormone-containing intrauterine device (IUD), which contains the hormone levonorgestrel, can ease cramps and lighten menstrual blood flow. Insertion of a hormone-containing IUD may also help shrink the uterus to shrink to a more normal size.
• Danazol, a medication that suppresses the pituitary gland’s creation of certain hormones, such as FSH. This may reduce pain and lighten menstrual flow.
• Gonadotropin-releasing hormone agonists, a class of medication that triggers the ovaries to stop producing hormones, can help reduce menstrual flow and pain.

These medications should not affect a woman’s ability to become pregnant, although it may take longer for women to conceive after they stop taking gonadotropin-releasing hormone agonists.  

Surgical options are also available, including:

• Endometrial ablation, which destroys the inner lining of the uterus, either with heat, cold, or radiofrequency. Once the lining has been removed, women experience lighter periods or, in some cases, no more menstrual bleeding. Pregnancy is no longer possible after this procedure. It’s important to note that endometrial ablation does not improve the pain associated with adenomyosis.
• Uterine artery embolization, which blocks the blood supply to the lining of the uterus. This results in lighter menstrual periods and less discomfort. The procedure also affects a woman’s fertility and shouldn’t be performed on someone who wants to become pregnant.
  
• Hysterectomy, or removal of the uterus, may be recommended for women with severe symptoms. Removing the uterus eliminates all symptoms of uterine adenomyosis, but also means a woman can no longer get pregnant.

A variety of treatments may help to ease the symptoms of uterine adenomyosis. The condition may be uncomfortable and affect quality of life, but it does not lead to more serious disease.  

Though there are treatment options available, time itself may also help to alleviate the pain and discomfort associated with uterine adenomyosis. After menopause, women may notice that their symptoms fade or disappear.

“The providers at Yale are expert in the medical and surgical treatment of adenomyosis,” says Dr. Seifi. “In patients who desire for future fertility, minimally invasive gynecologic surgery at Yale provides the option of focal resection of adenomyosis if focal adenomyosis has been confirmed with imaging, such as in an MRI.”