Adenomyosis is a condition characterized by pelvic pain and heavy bleeding. Until recently, it was thought to occur mostly in middle-aged women after having children. So why is this a topic for a pregnancy blog? Well, current research suggests that this condition could be silent or unknown in its early phases, which could mean it’s more prevalent in younger women than once believed. It is being diagnosed more frequently in women of childbearing age in recent years, perhaps due to advancements in imaging and minimally-invasive approaches to surgery.
What is it?
Adenomyosis is a benign (non-cancerous) condition of the female reproductive tract in which endometrial glands and tissue are found in the wrong place. Usually, endometrial tissue lines the inside of the uterus – this is what thickens then sheds during the menstrual cycle. However, in adenomyosis, the endometrial tissue and glands grow into the uterine wall. This causes problems when it thickens and sheds in this abnormal location. The result is an enlarged uterus accompanied by the following symptoms:
- Heavy and/or prolonged bleeding
- Severe pelvic pain and cramps
- Discomfort with sexual intercourse
What causes it?
The exact cause of adenomyosis is unknown. It has been suggested that it is more common in women who have had surgery on their uterus – think Cesarean section or removal of fibroids – but the research to support this is inconsistent. Other links have been found between adenomyosis and use of antidepressant medication or treatment with tamoxifen (a hormonal treatment for breast cancer). The majority of women diagnosed with adenomyosis to date are in their 40s or 50s and have had children.1,2
How common is it?
Here’s the long answer:
To understand how common adenomyosis is (or isn’t), one must understand how the diagnosis is made. Previously, the definitive diagnosis of adenomyosis was made with microscopic examination of the uterus, which would happen after hysterectomy (surgical removal of the uterus). It’s assumed that younger women who did not yet have children and who were seeking treatment for their symptoms would not choose to have a hysterectomy, since that would eliminate their chance of having children naturally. Therefore, adenomyosis was more commonly diagnosed in women after the age of 40 – presumably those who no longer wanted to conceive.
Another complicating factor is that adenomyosis can coexist with other diseases of the uterus, such as uterine fibroids or endometriosis. This makes it difficult to determine which problem is causing symptoms. Additionally, it’s possible that adenomyosis begins earlier in life but remains silent for years, so it isn’t diagnosed until it starts causing problems. For these reasons, the disease is not well understood.
And the short answer:
There is a wide range of estimates (5% to 70%), but no one is exactly sure what the prevalence of adenomyosis is. It’s likely that around 20 to 30% of women have it.3
Fortunately, better imaging techniques are now available, such as magnetic resonance imaging (MRI) and transvaginal ultrasound (MRI is a type of imaging that uses magnets rather than radiation to take pictures, and you’re probably familiar with ultrasound and its use in pregnancy). These types of imaging can help confirm the diagnosis of adenomyosis without the need for hysterectomy or other surgery. Medical professionals are hopeful that better imaging and increased awareness of adenomyosis can help lead to a better understanding of the disease process.
Adenomyosis and infertility
Recent research suggests that women with adenomyosis might have trouble getting pregnant, and they might also have a higher risk of miscarriage. This could be because the endometrium may act differently in adenomyosis and make it difficult for a fertilized egg to implant in the uterus. The good news is that treatments for adenomyosis are available, and treatment may improve a woman’s chances of getting pregnant. Obviously, more research is needed to understand this better.3
Considering how little is known about adenomyosis and the fact that is was previously only diagnosed by hysterectomy, the true numbers are difficult to pin down. But there is reason to believe it is more common than doctors previously thought.