Endometriosis & Miscarriage
The uterine lining, called the endometrium, helps prepare a woman's womb for pregnancy by providing a hospitable environment to a fertilized egg. Each month, in response to the hormonal signals of ovulation, the endometrium thickens. If fertilization does not occur, the uterine lining sloughs off and a woman has her menses.
Endometriosis is a condition in which endometrial tissue grows outside of the uterus. Pockets of endometrial tissue are usually found somewhere in the pelvic area, on the fallopian tubes, ovaries, bladder, etc. This tissue, like the normal tissue in the uterus, thickens and bleeds in a monthly cycle. Unfortunately, this blood and tissue does not have an outlet. Instead, it builds up inside the body and can cause inflammation and the formation of cysts, resulting in discomfort and pain.
Infertility and Miscarriage
Half of women with endometriosis will have problems with infertility. Many of these women (up to fifty percent) also miscarry when they do finally become pregnant. In comparison, the rate of spontaneous miscarriages for the general population is about ten percent. So why do women with endometriosis have so much more trouble becoming and staying pregnant? There are several factors related to endometriosis that make it difficult for women to conceive and carry to term:
The blood and tissue leaked by endometrial tissue into the abdomen can be harmful. In an attempt to protect itself, the body surrounds these patches with fibrous scar tissue. This scar tissue, combined with the blood from the implanted endometrial tissue, can cause these patches to stick to other organs in the vicinity. Depending on which organs become glued together, effects may vary. If the fallopian tubes become stuck to the ovaries, or if the fallopian tube is pinched off in some way, this will prevent the egg from traveling from the ovary down through the fallopian tube. This, of course, results in infertility. Depending on which organs are connected and how, these abdominal adhesions can also result in miscarriages. Ectopic pregnancies, pregnancies outside the uterus, are also more common in women with abdominal adhesions.
The endometrial tissue secretes many important hormones that help facilitate pregnancy. The endometrial implants secret these same hormones, but instead of secreting them into the uterus where they belong, they'll secrete them into the abdominal cavity or other parts of the body. These misplaced hormones may interfere with the pregnancy process. In addition, the implants often secrete hormones later than the cells lining the womb. This may cause the body to become confused and continue ovulating, even though a fertilized egg has already been implanted. When this occurs, the uterus sheds the old lining, including the egg, and a very early miscarriage results.
The Immune System
It is possible that the immune system may also play a role in the high infertility and miscarriage rates in women with endometriosis. The developing embryo is a foreign organism. A healthy immune system can identify it as a non-threat, but since the immune system of women with endometriosis does not functioning properly, it may not be able to make this distinction and might attack the embryo, resulting in miscarriage. If you have endometriosis and are trying to get pregnant, talk to your doctor. While most of the treatments used for endometriosis do not improve fertility, some types of surgery may make it easier to conceive and carry to term.