7400 Fannin St., Suite 1180
Houston, Texas 77054
Phone (713) 790-9900
Fax (713)-790-9901

Robert B. McWilliams, MD
Reproductive Endocrinology
and Gynecology


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Endometriosis is a common cause of pelvic pain and infertility (40%) in women. The lining of the uterus is composed of endometrial cells which have the capability to divide rapidly. This rapid division increases the vascularity of the endometrium thus preparing it to accept the developing fetus. Endometriosis occurs when the cells that normally line the uterus travel to other parts of the body, attach to various organs grow and divide. Endometrial cells require the hormone estrogen for sustained growth.

The most widely held theory of how endometriosis develops hypothesizes that endometrial cells "slough off" during the menstrual cycle and flow back through the fallopian tubes into the pelvic cavity. Once in the pelvic cavity endometrial cells can attach to any organ including the ovaries, uterus, spleen, kidneys, and bowel and have been seen in areas such as the lung. As the endometrial cells grow they obstruct organs, such as the tubes, and sometimes cause complete blockage and/or organ penetration. The severity of endometriosis is categorized by stages one(less severe) to stage 5 (severe).

Sometimes medications such as Lupron are effective endometriosis treatments. These drugs suppress FSH and LH hormone production leading to dramatically lower estrogen levels. When endometriosis is present in the infertile female, it is usually removed surgically via laparoscopy.

When fertility is an issue, the diagnostic/treatment laparoscopy should always be performed by a reproductive specialist. Specialists, such as Dr. McWilliams, undergo years of advanced training in delicate microsurgery and can often remove the endometriosis during the diagnostic laparoscopy. Meticulous care must be taken to remove all of the endometrial implants.

Endometriosis also has a genetic component and its incidence is higher in daughters of women who have/had the disease.