Endometriosis- Definition and Facts
Endometriosis and Infertility
Endometriosis can be associated with severe pain and fertility problems. About 30% to 40% of women with endometriosis have some trouble conceiving. The reason for this is not well understood, and scarring of the reproductive tract, or hormonal factors may be involved. Over time endometrial implants may grow, or cysts may result because of endometriosis, which also may cause fertility problems.
Quick GuideEndometriosis Symptoms, Stages, Treatment
Endometriosis definition and facts
- Endometriosis is the abnormal growth of cells (endometrial cells) similar to those that form the inside of the uterus, but in a location outside of the uterus. Endometriosis is most commonly found on other organs of the pelvis.
- The exact cause of endometriosis has not been identified.
- Endometriosis is more common in women who are experiencing infertility than in fertile women, but the condition does not necessarily cause infertility.
- Most women with endometriosis have no symptoms. However, when women do experience signs and symptoms of endometriosis they may include:
- Pelvic pain that may worsen during menstruation
- Painful intercourse
- Painful bowel movements or urination
- Pelvic pain during menstruation or ovulation can be a symptom of endometriosis, but may also occur in normal women.
- Endometriosis can be suspected based on the woman’s pattern of symptoms, and sometimes during a physical examination, but the definite diagnosis is usually confirmed by surgery, most commonly by laparoscopy.
- Treatment of endometriosis includes medication and surgery for both pain relief and treatment of infertility if pregnancy is desired.
What is endometriosis?
Endometriosis is the abnormal growth of endometrial tissue similar to that which lines the interior of the uterus, but in a location outside of the uterus. Endometrial tissue is shed each month during menstruation. Areas of endometrial tissue found in ectopic locations are called endometrial implants. These lesions are most commonly found on the ovaries, the Fallopian tubes, the surface of the uterus, the bowel, and on the membrane lining of the pelvic cavity (i.e. the peritoneum). They are less commonly found to involve the vagina, cervix, and bladder. Rarely, endometriosis can occur outside the pelvis. Endometriosis has been reported in the liver, brain, lung, and old surgical scars. Endometrial implants, while they may become problematic, are usually benign (i.e. non-cancerous).
What are the stages of endometriosis?
Endometriosis is classified into one of four stages (I-minimal, II-mild, III-moderate, and IV-severe) based upon the exact location, extent, and depth of the endometriosis implants as well as the presence and severity of scar tissue and the presence and size of endometrial implants in the ovaries. Most cases of endometriosis are classified as minimal or mild, which means there are superficial implants and mild scarring. Moderate and severe endometriosis typically result in cysts and more severe scarring. The stage of endometriosis is not related to the degree of symptoms a woman experiences, but infertility is common with stage IV endometriosis.
What are the signs and symptoms endometriosis?
Most women who have endometriosis, in fact, do not have symptoms. Of those who do, the most common include:
- Pain (usually pelvic) that usually occurs just before menstruation and lessens after menstruation
- Painful sexual intercourse
- Cramping during intercourse
- Cramping or pain during bowel movements or urination
- Pain with pelvic examinations
The intensity of the pain can vary from month to month, and can vary greatly among affected individuals. Some women experience progressive worsening of symptoms, while others can have resolution of pain without treatment.
Pelvic pain in women with endometriosis depends partly on where endometrial implants of endometriosis are located.
- Deeper implants and implants in areas of high nerve density are more apt to produce pain.
- The implants may also release substances into the bloodstream which are capable of eliciting pain.
- Pain can result when endometriotic implants incite scarring of surrounding tissues. There appears to be no relationship between severity of pain and the amount of anatomical disease which is present.
Endometriosis can be one of the reasons for infertility for otherwise healthy couples. When laparoscopic examinations are performed during evaluations for infertility, implants are often found in individuals who are totally asymptomatic. The reasons diminished fertility in many patients with endometriosis are not understood. Endometriosis may incite scar tissue formation within the pelvis. If the ovaries and Fallopian tubes are involved, the mechanical processes involved in the transfer of fertilized eggs into the tubes may be altered. Alternatively, the endometriotic lesions may produce inflammatory substances which adversely affect ovulation, fertilization, and implantation.
Other symptoms that can be related to endometriosis include:
- lower abdominal pain,
- diarrhea and/or constipation,
- low back pain,
- chronic fatigue
- irregular or heavy menstruation,
- painful urination, or
- bloody urine (particularly during menstruation).
Rare symptoms of endometriosis include chest pain or coughing blood due to endometriosis in the lungs and headache and/or seizures due to endometriosis in the brain.
What about endometriosis and cancer risk?
Some studies have postulated that women with endometriosis have an increased risk for development of certain types of ovarian cancer, known as epithelial ovarian cancer (EOC). This risk is highest in women with both endometriosis and primary infertility (those who have never conceived a pregnancy). The use of combination oral contraceptive pills (OCPs), which are sometimes used in the treatment of endometriosis, appears to significantly reduce this risk.
The reasons for the association between endometriosis and ovarian epithelial cancer are not clearly understood. One theory is that the endometriosis implants themselves undergo malignant transformation to cancer. Another possibility is that the presence of endometriosis may be related to other genetic or environmental factors that serve to increase a women’s risk of developing ovarian cancer.
What causes endometriosis?
The cause of endometriosis is unknown. One theory is that the endometrial tissue is deposited in unusual locations by the retrograde flow of menstrual debris through the Fallopian tubes into the pelvic and abdominal cavities. The cause of this retrograde menstruation is not clearly understood. It is clear that retrograde menstruation is not the only cause of endometriosis, as many women who have retrograde menstruation do not develop the condition.
Another possibility is that areas lining the pelvic organs possess primitive cells that are able to develop into other forms of tissue, such as endometrium. (This process is termed coelomic metaplasia.)
It is also likely the direct transfer of endometrial tissues at the time of surgery may be responsible for the endometriosis implants occasionally found in surgical scars (for example, episiotomy or Cesarean section scars). Transfer of endometrial cells via the bloodstream or lymphatic system is the most plausible explanation for the rare cases of endometriosis that are found in the brain and other organs remote from the pelvis.
Finally, there is evidence that some women with endometriosis have an altered immune response , which may affect the body’s natural ability to recognize ectopic endometrial tissue.