The endometrium is the lining of the uterus. Every month it becomes thickened in order to nourish an embryo. If there is no pregnancy, it becomes loosened and is shed, making up most of the menstrual blood loss. In endometriosis, some of the blood makes its way backwards along the fallopian tubes and into the pelvis, where patches of endometrium are found growing on internal organs - the tubes and ovaries, rectum and intestines, and the bladder. These patches of endometrium, like that inside the uterus, become thickened, then bleed with each menstrual cycle. The blood cannot, however, escape and the result is scarring and the formation of multiple blood-filled 'chocolate' cysts. Some menstrual blood presses up the tubes in most women, but only in a minority are patches of endometriosis formed, and the reason for this variation is still obscure.
Endometriosis is unpredictable and puzzling in its symptoms, too. It occurs more often in white women than in black ones, affecting mostly childless women in their thirties and forties. It may cause painful and heavy menstruation, backache, and deep internal pain during sex; less often, diarrhoea, rectal bleeding, and urinary symptoms. Yet it may cause no symptoms, and be discovered only when investigating infertility. As many as 15-20 per cent of infertile women have endometriosis, and around 30-40 per cent of women with endometriosis are infertile.
Infertility is, indeed, the central problem in treatment. Most of the symptoms of endometriosis will disappear if menstruation is stopped. This may be achieved by several hormone-modifying drugs; the best known is danazol. It has, however, several unpleasant side-effects including headaches, flushing, and sometimes masculinisation, deepening of the voice, acne, and the growth of body and facial hair. Other treatments are now available, using drugs which block the action of the pituitary hormones.
Suppression of ovulation and menstruation for a year or so usually leads to the gradual disappearance of pain as the endometrial patches become smaller and inactive. But if the woman's main concern is to become pregnant, this treatment is frustrating. A combination of surgery and hormonal treatment may be the most effective, but sometimes the best chance of pregnancy will be in vitro fertilisation. As pregnancy stops menstruation, it will relieve the symptoms of endometriosis.
Women who have completed their families or have no wish to become pregnant may choose a more radical treatment. Surgical removal of the uterus and the ovaries and tubes will also be curative. This is old-style, large-scale surgery, but it may be the best solution for a chronic, debilitating disease.Reuse content