March is Endometriosis Awareness Month, a national effort to increase visibility and understanding of this disease which affects an estimated 200 million people worldwide. John Petrozza, MD, chief of the Division of Reproductive Medicine and In Vitro Fertilization at Massachusetts General Hospital and director of the Mass General Fertility Center, explains what endometriosis is and how it can impact fertility.

What is endometriosis?

The tissue that lines the uterus is called the endometrium. Normally, if a person doesn’t get pregnant, this tissue is shed each month during their period. In endometriosis, tissue that looks and acts like endometrial tissue implants outside the uterus. This can cause pain, heavy periods and infertility.

How does endometriosis impact fertility?

Endometriosis is a common cause of infertility. This can happen if the endometrial tissue implants around the ovaries or fallopian tubes, where it can also cause inflammation and scar tissue. Tissue can also implant on other organs in the pelvis and, in some cases, outside the pelvis. In some people, this endometrial tissue can grow into the muscle of the uterus and cause another form of endometriosis, called adenomyosis. Endometriosis has also been shown to alter the immune system, change the hormonal environment around the eggs, inhibit implantation of an embryo and alter the quality of the eggs. Most often, endometriosis can be removed, along with any scar tissue, and your symptoms will improve, including your ability to conceive.

What are my chances of getting pregnant if I have endometriosis?

Endometriosis can make it more difficult to get pregnant. Between 30-50% of people with endometriosis may experience infertility. The normal chance of getting pregnant each month for people with no endometriosis is approximately 10-20%, while people with surgically documented endometriosis have a chance of only 1-10%.

What treatments for endometrial infertility exist?

A fertility specialist will consider your age, overall health, symptoms and other factors—including your desire to get pregnant—when determining which treatment is best for you.

Treatment choices include medicine, surgery or both. If symptoms are mild, you may only need pain medicine.

Health care providers may be able to remove abnormal tissue growths using a laparoscope. In rare cases, open surgery is needed. The fertility specialist will consider all your treatment options, determine your timeline to conceive and explain the best options for you to manage your symptoms.

What should a person with endometriosis do if they’re struggling to get pregnant?

If you suspect endometriosis and are struggling to get pregnant, you should make an appointment with your reproductive endocrinologist or gynecologist that specializes in endometriosis and reproductive surgery. They will review your health history and perform a physical exam. A laparoscopy is sometimes done to diagnose endometriosis, especially if you are having a lot of symptoms. This uses a thin tube with a lens and a light at the end. It’s inserted into an incision in the abdominal wall to help the physician see the pelvic area. Your health care provider can often find the locations, extent and size of the misplaced tissue. 

Sometimes, endometriosis is suspected based on findings from a pelvic ultrasound or other imaging study. There are also times when endometriosis is suspected based only on symptoms.

You also may be referred to a fertility specialist to discuss other treatment options for endometriosis that will preserve and improve fertility.