Many women who suffer a missed or incomplete miscarriage undergo a procedure called dilation and curettage (D&C), which is performed to remove tissue after the miscarriage. It is a procedure in which the cervix of the uterus is expanded so that the endometrium (uterine lining) can be removed with a spoon-shaped instrument called a curette; hence the name, dilation and curettage. A D&C may also be done to help determine the cause of abnormal uterine bleeding, or to determine the degree of cancer or pre-cancerous cells detected in a biopsy. Dilation and curettage has been implicated in about 90% of cases of Asherman's Syndrome.
Asherman's Syndrome - Intrauterine Scarring and Adhesions
Asherman's Syndrome, also known as intrauterine adhesions, scarring or synechiae, is an acquired condition of the uterus that is distinguishable by the formation of scar tissue inside the uterus. The adhesions may be mild, moderate or severe as bands of scar tissue join parts of the walls of the uterus to one another, causing the volume or size of the inside of the uterus cavity to be reduced. In many cases the front of the uterus is stuck to the back walls and in other cases only small portions of the uterus are stuck together.
The result of the reduction of space within the uterus caused by the adhesions is most frequently amenorrhea (no menstruation), or reduced menstrual flow accompanied by increased cramping and abdominal pain, recurrent miscarriage and infertility. Some women with Asherman's Syndrome have no bleeding but feel pain at the time their period would normally occur every month. It is possible that the pain indicates bleeding but there is no way for the blood to be released from the uterus due to a scar-blocked cervix.
Dilation & Curettage is the Primary Cause of Asherman's Syndrome
Trauma to the endometrial lining causes the normal wound healing process to take place, and Asherman's Syndrome occurs when the healing process occurs causing the areas that were damaged to fuse together. Along with dilation and curettage, Asherman's Syndrome may result from other types of pelvic surgeries like a c-section or surgery to remove polyps or fibroids. Infections such as genital tuberculosis and schistosomiasis, a disease caused by worms, also can result in Asherman's Syndrome.
The risk for developing Asherman's Syndrome is highest in situations where a D&C was performed after a missed miscarriage. Following are the statistics:
· 25% risk of developing Asherman's Syndrome from a D&C performed 2-4 weeks after delivery
· 30.9% risk following a D&C for missed miscarriages
· 6.4% risk of procedures for incomplete miscarriage
· 16% risk if only one D&C is performed
· 32% risk if three or more D&Cs are performed
Each case of Asherman's Syndrome must be evaluated on its own. Sometimes it is caused by an overly aggressive D&C, although this is not always the case. Sometimes the placenta attaches very deeply into the endrometrium or there is a lot of tissue left after a miscarriage in which there has been a lot of fibrotic activity. Both of these conditions can cause Asherman's Syndrome. It is thought that the incidence of Asherman's Syndrome is higher than reported and that it is under-diagnosed. The estimates indicate that 1.5% of women who undergo a hysterosalpingogram (HSG) are affected with Asherman's Syndrome; between 5 and 39% of women with recurrent miscarriage; and 40% of women who have had a D&C following childbirth or incomplete abortion where there were retained products of conception. The best and most effective way to diagnose Asherman's Syndrome is by direct visualization of the uterus using a hysteroscope, although both sonohysterography (SHG) and hysterosalpingogram (HSG) are also used in diagnosis.
Prevention is Best With Asherman's Syndrome
As is usually the case, the best offense is a good defense, and prevention is the ideal solution to this condition. It was noted nearly 20 years ago that the incidence of intrauterine adhesions (IUA) might be lower if the procedure was done using medical evacuation rather than using instruments. One study that has been performed supports this idea. It found that women who were treated with misprostol, a medical evacuation, did not develop IUA, and 7.7% of women who underwent D&C did. If a D&C is done under ultrasound guidance rather than blind scraping, the risk could be reduced significantly also. IUA may be prevented with the immediate evacuation following fetal death since adhesions are more likely to form over time.
Treatment For Asherman's Requires a Specialist
Treating Asherman's Syndrome should be done by a highly skilled surgeon using hysteroscopy, perhaps with the aid of a laparoscopy as well. Adhesions have a tendency to reform, especially if the condition is very serious. To prevent re-scarring, sometimes estrogen supplementation is given to speed healing. A splint or balloon may be inserted into the cervix to prevent the walls of the uterus joining together again immediately following surgery.
Uterine factors present a serious challenge to women who want to bear children. Learn more about the various factors that can affect the uterus in this section.