Isthmocele (Cesarean Scar Defect)

What is an isthmocele?

An isthmocele (cesarean scar defect) is a pouch that forms in the lining of your uterus. It occurs after a cesarean birth (c-section). The pouch (also called a uterine niche) develops when the c-section incision (cut) doesn’t heal completely. Isthmoceles can lead to infertility, complications during future pregnancies and other problems.

Who is at risk of getting a cesarean scar defect (isthmocele)?

Anyone who has a c-section can develop a cesarean scar defect. You’re at a higher risk if you:

• Have overweight/obesity before and during your pregnancy.
• Have a medical condition that prevents wound healing.
• Have an unplanned c-section late in the labor process.
• Have diabetes mellitus or develop gestational diabetes while pregnant.
• Have had multiple c-sections.
• Smoke or use tobacco products.

How common are isthmoceles?

Between 24% and 70% of people who’ve had at least one c-section develop an isthmocele. It’s becoming more common as c-section rates increase. About 30% of birthing people in the U.S. have c-sections.

What causes a cesarean scar defect?

A c-section involves two incisions: one in your abdomen and one in your uterus. If the incision in your uterus doesn’t heal completely or you’ve had multiple incisions in the same area, the surrounding tissue becomes thin. It can form a pouch that fills with fluid and blood.

The location of the c-section incision might affect whether you develop a scar defect. An incision that’s too low on your uterus tends to form a larger scar. Low incisions are more common when your c-section happens after you’ve been in labor for a while. A single layer of stitches to close the uterine incision (instead of a double layer) may also make isthmoceles more likely.

Can c-section scarring cause infertility?

Yes, c-section scarring sometimes causes infertility. But with treatment, many people go on to have healthy pregnancies. Talk with your healthcare provider if you have symptoms of an isthmocele (cesarean scar defect) or if you’ve been trying to get pregnant for 12 months without success (six months if you’re over the age of 35).

What are the symptoms of an isthmocele?

Symptoms can include:

• Abnormal menstruation (periods).
• Dysmenorrhea (painful menstrual periods).
• Dyspareunia (pain during sex).
• Pelvic pain.
• Vaginal bleeding or uterine bleeding between periods.
• Vaginal discharge.

What are the complications of an isthmocele?

Potential complications can include:

• Increased risk of complications during gynecological procedures.
• Placenta accreta (placenta attaches too deeply to the wall of your uterus).
• Placenta previa (placenta covers your cervix).
• Scar pregnancy (ectopic pregnancy where the egg implants in a uterine scar).
• Secondary infertility (infertility after a previous successful pregnancy).
• Uterine dehiscence (tear or rupture at the site of a uterine scar).

How are isthmoceles diagnosed?

Imaging exams are the most effective way to diagnose isthmoceles. The best time to perform imaging is right after your menstrual cycle, when the niche is likely full of blood. This makes it easier to see in images.

Your healthcare provider may perform:

• Hysteroscopy: During a hysteroscopy, your healthcare provider inserts a thin, lighted tube into your vagina. They examine the inside of your cervix and uterus for scarring, abnormal tissue or other issues.
• Saline infusion sonohysterography: This imaging exam provides more detail than a transvaginal ultrasound. Your healthcare provider fills your uterus with saline (sterilized salt water) before doing an ultrasound. The water fills the niche, making it easier to see its size and thickness in images.
• Transvaginal ultrasound: This imaging exam uses an ultrasound probe in your vagina to check for a uterine scar and niche. An ultrasound can also help your healthcare provider evaluate the thickness of the scar.

How are cesarean scar defects treated?

There are several treatments for isthmoceles, including:

• Oral contraceptives: Birth control pills deliver low doses of hormones. The hormones can regulate your periods and lighten menstrual blood flow. This treatment may also reduce the size of the niche enough that you can avoid surgery.
• Hysteroscopic resection (HR): During a hysteroscopy, your healthcare provider removes uterine scar tissue. They also open the sides of the niche to let blood and fluid drain out. HR doesn’t require abdominal incisions.
• Laparoscopic repair: Your healthcare provider makes one or more small incisions in your abdomen. They insert a thin, lighted tube (laparoscope) to see the inside of your uterus. They remove scar tissue and extra tissue around the niche. Laparoscopic repair is a minimally invasive surgery for cesarean scar defects. You recover more quickly and have less discomfort.
• Hysterectomy: A hysterectomy (uterus removal) is for people with severe isthmocele symptoms who don’t want to get pregnant again. You may be able to have a laparoscopic hysterectomy. This minimally invasive procedure uses smaller incisions than an open abdominal procedure. You heal faster and with less pain.

How can I prevent isthmoceles?

The only way to completely prevent isthmoceles is to not have a c-section. If you’re pregnant and are planning a c-section, talk to your healthcare provider about the risks of cesarean scar defects (isthmoceles). You may be able to reduce your risk by:

• Maintaining a weight that’s healthy for you before and during pregnancy.
• Managing diabetes.
• Not smoking or using tobacco products.

What is the outlook for people with cesarean scar defects?

Cesarean scar defects (isthmoceles) are treatable. Most people can still get pregnant after cesarean scar defect treatment.

When should I call my doctor?

If you have an isthmocele while pregnant, you’re at risk for a ruptured uterus. This is a medical emergency. It occurs if the uterine scar separates and your uterus tears open. It can pose serious health risks to you and your baby. Seek medical attention right away if you experience severe pelvic pain, pain at the site of a c-section scar or heavy vaginal bleeding. These could be signs of a ruptured uterus.

A note from Cleveland Clinic

An isthmocele is a pouch, or niche, of tissue that forms on the wall of your uterus. It’s the result of a c-section incision that didn’t heal completely. Isthmoceles can lead to abnormal vaginal bleeding, pelvic pain and menstruation problems. It can also cause infertility or problems with future pregnancies. The most common treatment is minimally invasive surgery to remove excess scar tissue and repair the niche. Most people can still have healthy pregnancies after treatment.