Asherman syndrome is a condition where scar tissue forms inside the uterus, causing bands of adhesions that can partially or completely block the uterine cavity. These adhesions typically develop after a surgical procedure on the uterus, most commonly a dilation and curettage (D&C) performed during or after pregnancy. The scarring can lead to lighter or absent periods, pelvic pain, and difficulty getting or staying pregnant.
How Scar Tissue Forms in the Uterus
The inside of your uterus is lined with a layer of tissue called the endometrium. This is the lining that thickens each month and sheds during your period. When the uterus is injured, particularly by surgical instruments scraping the walls, the damaged areas can heal by forming scar tissue instead of regenerating normal lining. These scars can create fibrous bands that stretch across the uterine cavity, essentially gluing the walls together in places.
The severity varies widely. In mild cases, thin, filmy adhesions cover a small portion of the cavity and the remaining lining still functions. In severe cases, thick, dense scar tissue can obliterate the entire cavity, replacing the functional lining almost entirely. The American Fertility Society classifies Asherman syndrome as mild, moderate, or severe based on how much of the cavity is blocked, what the adhesions look like, and how your menstrual pattern has changed.
Common Causes and Risk Factors
The most frequent trigger is instrumentation of the uterus during or shortly after pregnancy, when the tissue is particularly soft and vulnerable. A D&C performed after a miscarriage, to remove retained placental tissue after delivery, or to terminate a pregnancy carries the highest risk. The more procedures you’ve had, the greater the chance of adhesion formation.
Other causes include surgery to remove uterine fibroids (myomectomy), cesarean sections, and infections of the uterine lining. In some parts of the world, genital tuberculosis is a notable cause. Any procedure or condition that damages the deep base layer of the endometrium can set the stage for scarring.
Recognizing the Symptoms
The classic signs of Asherman syndrome are changes to your period, pelvic pain, and fertility problems. You might notice your periods becoming much lighter than they used to be, or they may stop altogether. In some cases, you still feel cramping at the time your period should arrive, but little or no blood comes out. This happens because menstruation is still occurring, but the scar tissue blocks the blood from leaving the uterus, which can cause significant pain.
Symptoms can include:
- Very light periods that are noticeably shorter or scantier than before
- Absent periods that develop after a uterine procedure
- Severe cramping or pelvic pain around the time of expected menstruation
- Difficulty getting pregnant despite regular attempts
- Recurrent miscarriages
Not everyone with intrauterine adhesions has symptoms. Some people discover the condition only when they’re being evaluated for infertility or recurrent pregnancy loss.
How Asherman Syndrome Is Diagnosed
A standard ultrasound can sometimes hint at adhesions, but it’s not reliable enough on its own. Two initial screening tools are saline sonography (where sterile salt water is pushed into the uterus during an ultrasound to outline the cavity) and hysterosalpingography (an X-ray taken after dye is injected through the cervix). Both can reveal filling defects where adhesions block the normal cavity shape, but their sensitivity sits around 75%, meaning they miss about one in four cases.
Hysteroscopy is the gold standard. A thin camera is passed through the cervix to look directly at the inside of the uterus. This allows the doctor to see exactly where the adhesions are, how thick they are, and how much of the cavity is affected. One major advantage is that treatment can happen during the same procedure. In the most severe cases, where the cavity is completely sealed shut, an MRI may be needed to map the extent of scarring before any intervention.
Surgical Treatment
The primary treatment is hysteroscopic adhesiolysis, a procedure where a surgeon uses a thin camera and specialized instruments passed through the cervix to cut through the scar tissue and restore the normal shape of the uterine cavity. No abdominal incisions are needed. In cases with extensive, dense scarring, an ultrasound probe on the abdomen guides the surgeon in real time to avoid accidentally cutting through the uterine wall.
After surgery, the goal is to keep the newly opened walls from scarring together again while the lining regrows. Doctors commonly place a temporary device inside the uterus or prescribe hormonal therapy (typically a combination of estrogen and progesterone taken in cycles) for about two months to encourage the endometrium to regenerate over the raw surfaces.
Hyaluronic acid gel applied inside the uterus after surgery is another strategy to prevent adhesions from reforming. A meta-analysis of multiple studies found that this gel reduced the rate of adhesion recurrence by roughly 58% compared to no barrier. The gel acts as a physical spacer, keeping the walls separated during the critical early healing window.
Some people need more than one surgery. Dense or widespread adhesions are harder to clear completely in a single session, and scar tissue has a tendency to reform, particularly in severe cases.
Fertility and Pregnancy After Treatment
Pregnancy is possible after treatment, but the odds depend heavily on how severe the adhesions were. Among people with mild scarring, about 61% achieved pregnancy after surgery. That number dropped to roughly 53% for moderate cases and 25% for severe cases, according to one study.
A larger cohort study of 500 women tracked outcomes within three years of adhesiolysis and found an overall live birth rate of 67.4%, with a miscarriage rate of 33%. The best outcomes were seen in younger women whose adhesions developed after a first-trimester procedure, who had lower-grade scarring, and who did not miscarry after the surgical repair.
Even after successful treatment, pregnancies following Asherman syndrome carry higher risks. These include preterm labor, low birth weight, and placental complications. The placenta may grow too deeply into the uterine wall (a condition called placenta accreta) or fail to detach properly after delivery. Close monitoring throughout pregnancy is standard for anyone with a history of significant intrauterine adhesions.
Can Asherman Syndrome Be Prevented?
The most effective prevention strategy is minimizing unnecessary uterine procedures. When a D&C or other intrauterine surgery is medically necessary, gentle technique and limiting the number of repeat procedures reduce the risk of deep endometrial injury.
For people who do need uterine surgery, the use of anti-adhesion barriers at the time of the procedure offers a meaningful layer of protection. Hyaluronic acid gels, injected directly into the cavity after the operation, are the most widely studied option. They create a temporary coating over the healing surfaces that dissolves naturally within days, giving the lining time to begin regrowing before the walls can stick together. Some surgeons use a thin film barrier that hydrates into a gel over 24 to 48 hours, serving the same purpose.
Hormonal therapy started shortly after surgery also supports lining recovery. Estrogen encourages the endometrium to thicken and cover exposed areas, reducing the window during which raw surfaces might fuse together.