Endometriosis is a disease defined by the presence of endometrial tissue outside of the uterus. Endometrial tissue normally lines the uterus and is shed during the menses. This disease is associated with pain and infertility. Diagnosis is made by laparoscopy (camera observation inside the abdominal cavity) and histological examination of lesions, but transvaginal ultrasound can often detect ovarian endometriomas (blood filled cysts – also called “chocolate cysts” present on the ovaries).
What are the symptoms?
Symptoms can include:
- pain with or before the menstrual period
- pelvic pain at other times of the month
- pain with intercourse
- pain with bowel movements/urination during menstrual periods
- lower back pain
- heavy or clotted periods
What causes endometriosis?
One longstanding theory is that backflow of menstrual blood through the fallopian tubes and into the abdominal cavity causes the onset of endometriosis. There is a space between the ovary and the fallopian tube, and blood can escape the uterus during the menses through this passage.
Endometriosis is more common in women who have heavy menses, blockage of tubes, and shorter menstrual cycles. It has been found that endometrial cells can attach to and grow on the peritoneum (the lining of the abdominal wall). Endometriosis is most often found in areas which would correlate to the positions nearest to the source of backflow (the ovaries, anterior and posterior cul de sac), and can also be induced in primates after injection of menstrual fluid into the abdominal cavity.
Why then do some women develop endometriosis and others do not, when it has been found that 75-90% of women have blood outside of the uterus during the menstrual period?
Endometriosis is 6-7 times more prevalent among first degree relatives of affected women than in the general population. These genetic factors often predispose women to hormonal factors which allow the growth of endometriosis. Many women may not even be aware they have endometriosis, since there may be differing severities and since laparoscopy is ofen required to detect it. Often then, genetic factors for the disease do not become evident within families since many cases go undiagnosed (often simply as “painful periods”).
Related to the genetics previously discussed, women with endometriosis have different factors that alter normal estrogen metabolism in the tissues of the endometrial lining. An enzyme known as aromatase has been found in the endometrial tissue of women who have the disease. In the endometrium of women without endometriosis, aromatase is not found. Aromatase converts androgens (male hormones) in the local tissue into estrogen. The increased estrogen then results in local growth of the endometriosis lesions. Estradiol then stimulates a COX-2 inflammatory pathway which actually creates positive feedback for the production of even more estrogen locally in the area of the lesions. Endometriosis also has significant autoimmune components, and antibodies are secreted that can interfere with implantation.
Furthermore, two forms of estrogen are altered in women with endometriosis, which is significant because estrogen causes endometriosis tissues to grow. Estrone is a weak form of estrogen, and estradiol is a much more potent form of estrogen. Estrone is converted to estradiol and vice versa by two enzymes that work with the help of progesterone. In a normal endometrium, progesterone is able to increase the conversion of estradiol (strong) to estrone (weak), thereby keeping the growth effects of estrogen on tissues under control. In endometriosis, the enzyme which converts estradiol to the weaker form estrone is not at all found in the endometrial tissue. This causes levels of the stronger estradiol to accumulate. The enzyme which converts weaker estrone to stronger estradiol, however, is fully functional. This results in even higher amounts of more powerful forms of estrogen at the level of the endometrial lesions, causing more and more growth of this tissue outside of the uterus.
Endometriosis causes much pain for many women. It does this by causing inflammation in the peritoneal cavity, by the effect of bleeding outside of the uterus, and by irritation of nerves on the pelvic floor.
Endometriosis can reduce fertility in a few different ways.
It can alter the normal anatomy of the area where the ovary meets the fallopian tube because of physical obstruction by lesions. This can make it difficult for the egg to enter the tube after ovulation.
There are effects on the development of the egg and the embryo in endometriosis patients. This is seen when results of women undergoing IVF are considered. In women with endometriosis, there are less eggs retrieved, lower peak estrogen levels, and poorer embryo development. This is likely due to local hormonal factors.
It may also reduce the ability of the egg to implant. This happens because the function of the endometrium in women with endometriosis is altered.
The effect of endometriosis on fertility correlates with the severity of the disease : in patients with mild disease, effects on fertility are milder.
In integrative naturopathic medicine there are several effective research based treatments. Goals are to reduce production of harmful estrogens and thereby reduce growth of pathogenic tissue, to reduce inflammation, to enhance circulation and endometrial receptivity, and to shrink deposits of endometrial tissues,
Speroff, Clinical Gynecologic Endocrinology and Infertility. 7th Edition 2005.