Endometriosis - Complications

In this process, the body over produces specific immune factors that contribute to infertility, such as the following:

Cytokines. Cytokines are very potent immune factors that, when overproduced, cause damage and inflammation in the very regions that are directed to protect. Such damage could produce scarring and obstructions that interfere with implantation and development of a fertilized egg. In severe endometriosis, researchers have also observed inflammation in the fluid surrounding the uterus, which could create a hostile environment for the sperm. In one laboratory test, slower sperm were noted in fluid taken from women with moderate or severe endometriosis, although not in mild endometriosis.
Prostaglandins. Elevated levels of these factors not only produce inflammation but increase uterine contractions. (Women with endometriosis have a higher than average risk for miscarriage.)
Other Immune Factors. Growth factors (which stimulate growth of new blood vessels) and toxins produce by the implants could impair fertility.

Other Conditions Linking Endometriosis and Infertility. Researchers have sometimes noted unusually low levels of specific substances that enable a fertilized egg to adhere to the uterine lining. (Such abnormalities are more often a factor in infertility in women with mild to moderate endometriosis than in those with severe cases.)

One study found that the eggs in women with endometriosis appeared to have more genetic abnormalities than those in women without the disorder.

Effects on Other Parts of the Pelvic Region

Implants can also occur in the bladder (although rare) and cause pain and even bleeding during urination. Also rarely, implants form in the intestine and cause painful bowel movements, constipation, or diarrhea. (Hormonal treatments, the standard therapies for endometriosis, are not helpful in such cases, and surgery may be needed.)

Cancers

Endometriosis has characteristics that are similar to cancerous tumors, including cellular invasion of other tissues, unrestrained growth, development of new blood vessels, and impaired ability of cells to naturally self-destruct. It is not a malignant disease, however, but experts have been debating for years whether it represents any significant danger.

The possible risks for ovarian and endometrial cancers are of specific concern. Some researchers have identified certain genetic mutations that may transform endometrial cells into ovarian or endometrial cancers in rare cases. (Some evidence suggests that ovarian cancer associated with endometriosis may differ from most ovarian cancer cases, and, in fact, have a better outlook.)