OhioHealth Online

In a female fetus, the uterus starts out as two small tubes. As the fetus develops, the tubes normally join to create one larger, hollow organ — the uterus. Sometimes, however, the tubes don't join completely. Instead, each one develops into a separate cavity. This condition is called double uterus (uterus didelphys).

Double uterus is rare — and sometimes not even diagnosed. According to one estimate, uterine abnormalities occur in as many as 4 percent of women who have normal pregnancies, and of these women, about 5 percent have a double uterus. The percentage of women with a double uterus is likely higher in women with a history of miscarriage or premature birth.

Treatment is needed only if a double uterus causes symptoms or complications, such as pelvic pain or repeated miscarriages.

Some women have a double uterus and never realize it — even during pregnancy and childbirth. Each cavity in a double uterus often leads to its own cervix. Some women with a double uterus also have a duplicate or divided vagina.

Possible signs and symptoms may include:

• Unusual pain before or during a menstrual period
• Abnormal bleeding during a period, such as blood flow despite the use of a tampon

Researchers don't know what causes double uterus. This condition may be associated with kidney abnormalities, which suggests that something may influence the development of these related structures before birth.

Many women with a double uterus have normal sex lives, pregnancies and deliveries. But sometimes a double uterus leads to infertility or miscarriage. A double uterus may also cause premature birth or unusual positions of the baby in the uterus, such as bottom down (breech presentation).

A double uterus is often diagnosed during a routine pelvic exam when the doctor observes a double cervix or feels an abnormally shaped uterus. If the doctor suspects an abnormality, he or she may recommend any of the following tests:

• Magnetic resonance imaging (MRI). This test uses a strong magnetic field to create cross-sectional images of the inside of your body. There's usually no special preparation needed for an MRI; however, the test is conducted in a confined space, and is noisy. It's a good idea to let your doctor know if you're bothered by small spaces or loud noises. He or she may prescribe a mild sedative to make you more comfortable during the test. MRI scans are painless, and there are no known risks from the procedure.
• Ultrasound. This test uses high-frequency sound waves to create images of the inside of your body. To capture the images, a device called a transducer is used. The transducer sends the images to a computer screen. During the test, the transducer is either pressed against your abdominal skin or inserted into your vagina (transvaginal ultrasound). Both types of ultrasound may be done to get the best view of the uterus. To make imaging of the uterus easier through the abdomen, you'll need to drink enough fluid before the exam to fill your bladder. Your doctor will let you know exactly how much to drink and how soon before the exam you need to drink the extra liquids.
• Hysterosalpingography. For this test, a special dye is injected into your uterus through your cervix. This part of the test may be slightly uncomfortable. If you're concerned, ask your doctor to prescribe a mild sedative for the test. As the dye moves through your reproductive organs, X-rays are taken to determine the shape and size of your uterus. These X-rays are displayed instantly on a TV-like monitor.

If you have a double uterus but you don't have signs or symptoms, treatment is rarely needed. Surgery to unite a double uterus is rarely done — although surgery may help you sustain a pregnancy if you have a partial division within your uterus and no other medical explanation for a previous pregnancy loss.

If you're pregnant and have a double uterus, your risk of pregnancy complications may be higher due to the smaller size of your uteri. Share any concerns you may have about childbirth with your doctor, because he or she may suggest ways to help prevent preterm delivery or manage labor.