Asherman's Syndrome (Intrauterine Adhesions)

What happens in Asherman's syndrome

The uterus is lined by the endometrium, which has a deep basal layer that regrows the lining each month. If this basal layer is damaged, the raw surfaces of the uterine walls can stick together as they heal, forming bands of scar tissue. Adhesions can be thin and filmy or thick and dense, and can involve a small area or the whole cavity. Scarring also reduces the healthy lining available for periods and for an embryo to implant.

Causes and risk factors

• D&C after pregnancy: the most common cause. A D&C for a miscarriage, retained placenta or bleeding after delivery carries the highest risk, because the pregnant uterus is soft and the lining is vulnerable. Risk rises with each repeat procedure.
• Other uterine surgery: removal of fibroids or polyps, cesarean section, and surgery for uterine septum.
• Retained products of conception that need removal. See retained products of conception.
• Infection: endometritis, and in some parts of the world, genital tuberculosis.
• Uterine artery embolization or radiation to the pelvis (less common).

Symptoms

• Changes in periods: much lighter, shorter periods (hypomenorrhea) or no periods at all (amenorrhea) after a uterine procedure, despite normal hormone levels and ovulation.
• Cyclical pelvic pain or cramping: if scarring blocks the cervix or lower uterus, menstrual blood can be trapped, causing monthly pain without bleeding.
• Infertility.
• Recurrent miscarriage.
• Some people have no symptoms, especially with mild adhesions.

Diagnosis

A doctor will ask about previous pregnancies, procedures, infections and changes in your periods. Ovulation and hormone levels are usually normal, which helps distinguish Asherman's from hormonal causes of absent periods.

• Hysteroscopy: a thin camera passed through the cervix to look directly inside the uterus. This is the gold standard for diagnosis and allows treatment at the same time.
• Saline infusion sonohysterography: ultrasound while saline fills the uterus, outlining adhesions.
• Hysterosalpingogram (HSG): an X-ray dye test showing filling defects in the cavity.
• 3D ultrasound and MRI: sometimes helpful, especially for assessing the lining.

Severity is graded (for example mild, moderate or severe) based on how much of the cavity is involved, how thick the adhesions are, and menstrual patterns.

Treatment

Hysteroscopic adhesiolysis

The main treatment is cutting and removing adhesions under direct vision using small scissors or energy devices passed through a hysteroscope. The aim is to restore the normal shape of the cavity while preserving as much healthy lining as possible. Severe cases may need more than one procedure, and are best treated by a specialist experienced in this surgery.

Preventing scar tissue from reforming

Adhesions can return after surgery. Measures that may be used include:

• A temporary barrier: a small balloon catheter or an intrauterine device placed in the uterus for days to weeks
• Adhesion barrier gels
• Estrogen therapy to help the lining regrow, often followed by progestin to trigger a period
• Follow-up hysteroscopy to check results and divide any new thin adhesions early

Pregnancy after Asherman's syndrome

Many people conceive after treatment, especially with mild to moderate disease. Pregnancies after Asherman's syndrome carry higher risks of miscarriage, preterm birth, poor growth of the baby and problems with the placenta, including placenta accreta, where the placenta grows too deeply into the uterine wall. Prenatal care should be with an obstetric team aware of the history, and delivery planned in a hospital that can manage heavy bleeding.

Outlook

Outcomes depend on the severity of scarring. Normal periods return in most people after treatment of mild to moderate adhesions. Severe scarring is harder to treat, recurrence is more common, and pregnancy rates are lower. Some people with severe, untreatable disease consider gestational surrogacy for parenthood.

Prevention

• Medical management of miscarriage with medicines, or expectant management, avoids surgery where appropriate.
• When uterine evacuation is needed, suction methods and ultrasound guidance reduce trauma to the lining.
• Prompt treatment of uterine infection.

Frequently asked questions

What is Asherman's syndrome?

Asherman's syndrome is the formation of scar tissue inside the uterus, usually after a D&C or other uterine surgery. The scar tissue can partly or fully seal the uterine cavity, causing light or absent periods, pelvic pain, infertility and recurrent miscarriage.

What are the symptoms of Asherman's syndrome?

The most common symptoms are much lighter or absent periods after a uterine procedure, monthly cramping without bleeding, difficulty getting pregnant and repeated miscarriages. Some people with mild scarring have no symptoms at all and are diagnosed during fertility investigations.

Can you get pregnant with Asherman's syndrome?

Yes, many people do, especially after treatment of mild to moderate scarring. Pregnancy carries higher risks of miscarriage, preterm birth and placenta problems such as placenta accreta, so it needs close specialist care. Severe scarring lowers the chance of pregnancy.

How is Asherman's syndrome treated?

It is treated with hysteroscopic surgery to cut the adhesions and restore the uterine cavity. A balloon, IUD or gel may be placed afterward to stop the walls sticking together, and estrogen helps the lining regrow. A follow-up hysteroscopy checks for recurrence.

Does every D&C cause Asherman's syndrome?

No. Most D&Cs do not cause it. The risk is higher after a D&C for miscarriage or bleeding after delivery, after repeated procedures, and when infection is present. Medical management of miscarriage and gentle suction techniques reduce the risk.