Endometriosis is tissue normally found lining the inside of the uterus that has implanted in an abnormal location outside of the uterus.

Other locations include incisions from previous surgeries, the vagina and cervix, as well as the bowel and bladder. Very unusual locations are also possible but not as common.

Endometriosis is found in as many as 35 percent of women having laparoscopy for evaluation of their infertility. It can be a cause for pelvic pain as well as infertility.

Specialists vary tremendously on their opinions as to what should be done for the infertile couple with endometriosis. There is supportive evidence for most of the different treatment types which makes things even more confusing for patients seeking "the right thing."

Duke Center for Endometriosis Research & Treatment offers expert care to diagnose and treat endometriosis.

Origins of Endometriosis

Reflux
During menstruation the endometrial tissue becomes detached from the wall of the uterus and travels out the fallopian tube and into the abdomen instead of passing out of the cervix into the vagina. Endometrial reflux has been well documented and is widely accepted as a theory.

The presence of endometrial implants alone does not completely explain why women experience infertility. This idea also fails to answer the problem of infertility and pain, but some people argue the cyclic response of the endometrium to hormones (just like the normal endometrium) can cause pain and infertility.

Metaplasia
It has been proposed that cells lining the abdomen undergo a transformation known as metaplasia and give rise to endometrium-like tissue. This idea has not had widespread acceptance and may play a minor if any role in the problem of endometriosis.

Immunologic
This theory holds that patients have an inability to clear the menstrual debris from the abdomen and women are more likely to have residual endometrial implants. There is likely a great deal of merit to the immunologic response as a key role in the development of endometriosis.

Explaining Endometriosis

Combining the idea of menstrual reflux and an altered immune response paves the way for the current thinking of our physicians. The immune response is altered from the normal in that it doesn't fail to respond, but instead, responds too aggressively.

The menstrual reflux is quite often caused by cervical stenosis or some other obstruction of the outflow tract. This causes increased menstrual debris in the abdomen. If the immune system is slow to clear the debris, visible implants of endometriosis will be present.

An activated, or hyperactive, immune response will result in rapid clearing of the menstrual debris, and in fact, any debris. Because the white blood cells do not differentiate between endometrium, sperm, or egg, the sperm and egg are readily cleared from the abdomen as well.

Since the activation and activity of white blood cells causes a release of inflammatory chemicals, patients often experience pain. It is not uncommon for patients to experience debilitating abdominal pain with minimal visible evidence of endometriosis.

Physicians are likewise able to find patients with significant endometrial implants with minimal to no pain (likely a slow immune response with far less white blood cell mobilization). The presence and activity of peritoneal macrophages has been studied extensively at Duke.

Fertility Treatment Options

Treatment for infertility resulting from endometriosis can take one of two forms. By increasing the numbers of sperm and eggs in the abdomen one will increase the chances a sperm and egg are not destroyed by the white blood cells. While not as effective as IVF, many patients are able to successfully conceive a pregnancy through this method.

Ablation of endometriotic implants may help alleviate pain but is not likely to provide significant improvement in fertility since the immune response will be triggered again by the next menses. Perhaps even to a greater extent than from the presence of implants from previous cycles.

Long-term suppression of endometriosis can be achieved by Lupron and progestins. These work by decreasing the amount of reflux, and to a lesser extent on endometrial implants. Cervical dilation can also decrease the amount of menstrual reflux, though its effect may not last long-term.

Hysterectomy remains the definitive treatment for endometriosis. There is much debate about leaving ovaries behind in the presence of endometriosis implants, though there have been few well-organized studies answering this question. It is very likely to be a reasonable alternative to hormone replacement therapy.

Learn More

Learn about other potential diagnoses:

• Adenomyosis
• Enlarged Thyroid
• Fibroids
• Ectopic Pregnancy
• Galactorrhea
• Hydrosalpinx
• Ovarian Cysts
• Ovarian Hyperstimulation Syndrome
• Polycystic Ovarian Syndrome (PCOS)
• Pregnancy Loss