Endometriosis is a condition where endometrium, the tissue which normally lines the uterus, is found outside the uterus, usually in the pelvis behind the uterus. This can result in irritation, inflammation and scaring in the pelvis. The abnormal endometrium slowly grows and causes scarring. If it is present on the ovaries it may lead to cyst formation in the ovary.
Endometriosis is a common condition that affects 5-10% of women at some stage during their menstruating years and increases with age. It is one of the leading causes of infertility in women and 25-50% of infertile women will have some degree of Endometriosis. Endometriosis reduces the chance of pregnancy by altering the endometrium in the uterus so that it is less likely for the fertilised egg to implant and continue developing. This effect is due to the release of inflammatory factors by the abnormally sited endometrium. It doesn’t appear to stop fertilisation of the egg or increase the rate of miscarriage although this is an area of some controversy at present.
Classically the symptom associated with Endometriosis is pelvic pain, particularly with periods and intercourse. This is more likely if the pain is a new development, i.e. wasn’t there before. It may also cause changes in the menstrual cycle, particularly heavier periods and pre- and postmenstrual spotting. However, many women with fertility problems will have no symptoms at all – other than the difficulty falling pregnant.
The only way to diagnose Endometriosis with certainty is to have a laparoscopy (see below for more information). A laparoscopy is performed under general anaesthesia and a fine telescope is inserted through a 10mm incision in your navel and another instrument inserted through a 10mm incision just below your pubic hair line. If you have Endometriosis present it will be removed at the time unless it is very extensive. If it is extensive and particularly if it involves the bowel, we would need to operate at a later date after preparing your bowel prior to surgery. This is done because there is an increased risk of injury to the bowel in these circumstances and it is important both to prepare the bowel and to discuss the risks more fully before proceeding with the surgery.
It is a commonly held belief that a normal pelvic ultrasound scan rules out the diagnosis of Endometriosis. Unfortunately this is not true. Ultrasound will only pick up Endometriosis if it has caused a cyst in one or both ovaries. If there is an endometriotic cyst detected in an ovary, research shows that there is a 90% chance of there being Endometriosis present elsewhere in the pelvis. Endometriotic cysts (also called endometriomas) can usually be removed at laparoscopy as well.
A number of hormones have been used to treat Endometriosis and so avoid having surgery (oral contraceptive pill, progesterone, pituitary suppression, Danazole, Mirena IUD). The studies on the different agents clearly show that they are all similar in their effectiveness in controlling the symptoms of Endometriosis so it is best to use the simplest drug with the fewest side effects. There is a lot of debate in the medical literature about whether surgery or drug therapy is better. My view is that the hormonal treatment can sometimes control the symptoms (heavy periods, period pain) but that it will not cure significant Endometriosis. The other problem with hormonal treatment is that it usually prevents pregnancy and is therefore not helpful if the main issue is fertility. If all visible Endometriosis is removed at surgery there is an 80% chance of cure and, if it does recur, in my experience it comes back in 2-3 years at different sites and can be successfully removed again.