Endometriosis

* Endometriosis, a cause of female infertility, is a common disorder that affects women during their reproductive years. It occurs when endometrial tissue, the tissue that lines the inside of the uterus, grows outside the uterus. This misplaced tissue may implant and grow anywhere within the abdominal cavity, or rarely in distant sites such as the naval or lungs. This tissue may grow in small, superficial patches called implants; in thicker, penetrating nodules; or causing scar tissues (adhesions) that can block the fallopian tubes or interfere with ovulation. Another result of endometriosis is the formation of ovarian cysts called endometrioma that may also interfere with ovulation. Endometriosis is a progressive disease that tends to get worse over time and can reoccur after treatment.

What causes Endometriosis?

* The cause of endometriosis is unknown though there are a few theories that suggest possible causes. No one theory seems to explain all cases. The postulated theories:
* One theory suggests that during menstruation, some of the menstrual tissue backs up through the fallopian tubes into the abdomen where it implants and grows.
Another theory indicates that it is a genetic birth abnormality in which endometrial cells develop outside the uterus during fetal development. This is evidenced by the tendency for it to run in families. Patients with an affected mother or siblings are more likely (61 percent) to have severe endometriosis than those without affected relatives (23 percent).
An abnormality in the immune system allows normally shed endometrial cells to attach and grow. The immune system is responsible for clearing abnormal cells and bacteria from the body. Retrograde menstruation may overwhelm the body's ability to get rid of the endometrial cells discharged into the pelvic cavity. This may result in implantation and growth of the residual endometrial tissue. Researchers have reported measurable differences in various cells and chemicals related to the immune system in some woman with endometriosis.

How common is it?

All women 2-6%
Infertile women 25-45%

How Does Endometriosis Cause Fertility Problems?

* In cases where there is obvious disruption of the normal anatomy, endometriosis is a known cause of fertility problems. In fact 30-40% of patients with endometriosis are infertile. This is two to three times the rate of infertility in the general population.
* Under the influence of cycling female hormones, each month the displaced endometrial tissue grows and sheds blood at the time of menses. Instead of flowing harmlessly outside the body, however, the excrement causes destruction in the abdominal cavity.
* The resulting chronic tissue inflammation leads to the formation of adhesions and scars, which surround and entrap delicate reproductive organs. The adhesions can be so extensive that they literally freeze the tubes, ovaries, and uterus into place (stages III and IV). The eggs themselves are trapped in the scar tissue surrounding the ovaries, and infertility results.
* Studies have shown that the risk of miscarriage is higher for women with untreated endometriosis than in those without it. Some researchers suggest that the woman's body may form antibodies against the misplaced endometrial tissue. The same antibodies may attack the uterine lining and cause the high spontaneous-abortion rate: up to three times the normal rate. (Fortunately, removing the endometriosis with medication or with surgery will reduce this risk to normal.)
* Even mild forms of the disease (stages I and II) may interfere with fertility. It is hypothesized that the prostaglandins (hormones) secreted by the active, young endometrial implants or other chemicals secreted by white blood cells may interfere with the reproductive organs by causing muscular contractions or spasms. The tube may be unable to pick up the egg, and the stimulated uterus may reject implantation. In addition, sperm motility may be adversely affected along with the ability of the sperm to penetrate into the egg. Although the mechanisms are not fully understood, endometriosis may also result in anovulation (17 percent), cause a luteal phase defect interfering with implantation, or cause a luteinized unruptured follicle.

Luteinized Unruptured Follicle syndrome (LUF):

In these women although the follicle, where the egg grow, reach the appropriate size, it is not released to be picked up by the fallopian tube where it should meet the sperms. This happens despite normal hormonal parameters (LH surge). The cause behind this is not fully understood but endometriosis is found in 63% of those patients reported to have LUF.