What is Asherman’s Syndrome?
First described in 1948 by Dr Asherman, it was noted that some women having surgical treatments around the time of pregnancy did not have any subsequent periods. It was found that adhesions (scar tissue) inside the uterus would cause the uterine walls to stick together leading to decreased or no menstrual flow, sometimes in association with pain. Scar tissue inside the uterus that occurs unintentionally following a pregnancy, pelvic infection or surgical procedure is termed Asherman’s syndrome and is different to an endometrial ablation which specifically tries to induce scar tissue in the uterus to prevent heavy periods. The main concern with Asherman’s syndrome is that it can lead to problems becoming pregnant or pelvic pain due to the intrauterine scarring.
How does Asherman’s syndrome occur?
There are a variety of causes of Asherman’s syndrome that most commonly occur around the events of a pregnancy, but may occur at other times as well. For women who are not pregnant, rarely treatments such as curettes, removal of fibroids or polyps from the uterus or pelvic infection may cause scarring that leads to Asherman’s syndrome. During pregnancy, there is a higher chance of developing intrauterine scarring since the endometrium or lining layer of the uterus is thinner and more prone to damage. In addition, pelvic infections are more common at this time and healing of these tissues will usually result in the formation of scar tissue. It is uncertain why some women will develop Asherman’s syndrome following what seems to be relatively simple procedures or infection, whereas other women do not suffer the same problems.
Hormones probably have some role to play in the development of Asherman’s syndrome. Oestrogen is the hormone that causes the endometrium (uterine lining) to grow and low levels may predispose to the development of scar tissue in the uterus. This is true around the time of pregnancy and breast-feeding when the predominant hormone is progesterone. The high levels of progesterone and the low levels of oestrogen create an environment where it is more likely to develop. In the treatment of Asherman’s syndrome, oestrogen is often used to help the endometrium grow and it is prescribed in order to thicken the uterine lining quickly.
What are the symptoms of Asherman’s syndrome?
Reduced or absent menstrual flow, especially after a pregnancy and delivery, a miscarriage or termination of pregnancy or known pelvic infection is the most common symptom. Pelvic pain may also occur with areas of trapped menstrual fluid being squeezed by the surrounding muscular walls of the uterus. If the cervix is blocked by scar tissue completely then the fluid that builds up behind the obstruction cannot flow out and the pressure can cause pain that is sometimes so great that it requires admission to hospital and strong pain killers. This condition is called a haematometra and is like a large bruise inside the uterus. It can usually be diagnosed with a pelvic ultrasound and will often require a surgical procedure to relieve the obstruction.
It is presumed that adhesions can affect fertility, however the degree that these adhesions cause difficulties in becoming pregnant is unknown, since there may be women who have adhesions and become pregnant easily. The diagnosis may be made in two different ways. One is by an indirect test using an ultrasound or an X-ray, where the inside of the uterus may be assessed. In these tests, is a thin tube is placed through the cervix into the uterus and a fluid is pushed into the uterine cavity. The dye will flow all around the cavity, with the scar tissue causing an abnormal shape or shadow seen on the X-ray or ultrasound.
The second way that Asherman’s syndrome may be diagnosed is by a hysteroscopy. This is where a thin telescope is placed into the uterine cavity through the cervix. It does not require any incisions. The telescope is then able to locate any adhesions, which may be present, and they can be treated.
How is Asherman’s syndrome treated?
The best way to treat Asherman’s Syndrome is by a surgical procedure that is used to remove scar tissue from the uterine cavity and restore it to normal function. If you have been diagnosed or are thought to have Asherman’s syndrome you will be admitted to hospital and have your procedure performed under a general anaesthetic. You will have your legs placed in stirrups in the operating room and sterile covers will be placed over your legs and abdomen for the procedure.
A thin telescope (a hysteroscope) is then used to look through the cervix and find areas of scar tissue. If there is scar tissue in the cervix, then it may be necessary to break this down before the tip of the hysteroscope can be advanced. To assist in this process, a fine hollow needle is used to find the usual passage where there is no scar tissue. Using a special dye and an X-ray machine, pockets of normal endometrium without scar tissue are located in the uterine cavity and the tip of the needle is then used to break down the scar tissue and eventually open up all of these scarred areas to restore the cavity to normal. The same dye and X-ray machine can also be used to check that the tubes are open and that it would be possible for a spontaneous pregnancy to occur after treatment.
At the beginning of the procedure, you will be given antibiotics to reduce the risk of infection and will be prescribed oestrogen to be taken for about three weeks following your treatment to ensure that your body has every opportunity to repair the endometrium naturally and reduce the risk of the scar tissue reforming. At the end of the three week period, the oestrogen is stopped for one week, but may be recommenced for a further three weeks on and one week off cycle. A repeat hysteroscopy is then performed 4, 8 or 12 weeks later to check whether the uterine cavity and cervix are normal and would allow both normal menstruation and the possibility of pregnancy. If you have scar tissue in the upper part of the cervix where there is less endometrium and less blood flow, then the chance of having the scar tissue reform is greater than if the adhesions are occurring in the main part of the uterine cavity.