Uterine Anomalies

Uterine anomalies at a glance

• Uterine anomalies are anatomical problems with the uterus that women are born with (congenital anomalies), including a septate, unicornuate, or bicornuate uterus.
• Many women do not realize they have a uterine anomaly unless they experience symptoms, undergo an examination, or discover it through imaging (such as ultrasound). Even with the presence of an anomaly, the uterus may still function normally.
• Uterine anomalies may cause a woman to have irregular periods or no period, recurrent miscarriage, and infertility, as well as problems delivering during pregnancy.
• Some anomalies do not require any treatment; symptomatic anomalies may be corrected through minimally invasive surgery.

Causes & symptoms of uterine anomalies

Uterine anomalies develop when a female is growing in her mother’s womb. The uterus and part of the vagina normally develop from tissue on the left and right side of the body, fusing together to create the hollow uterine cavity. Anomalies occur when this structure does not fuse correctly or does not hollow out completely.

The various uterine development conditions include, bicornuate, unicornuate and septate uterine anomalies. Images of uterine anomalies can be seen at MedlinePlus.

Bicornuate uterus

A bicornuate uterus, is a partially split uterus that has formed in the shape of a heart, with two “horns” or areas at the top of the uterus. The abnormal shape can cause recurrent pregnancy loss (in the second trimester), preterm delivery, or fetal growth retardation, particularly if the embryo implants in one of the horns where there is not enough room or adequate lining for the baby to grow.

Additionally, babies generally turn head down near the end of pregnancy, but due to the shape of a bicornuate uterus, the baby may fit inside the uterus better head up, causing breech or transverse births. However, a woman with a bicornuate uterus may still be able to have a normal pregnancy.

Unicornuate uterus

A unicornuate uterus is when only one side of the uterus develops, usually with a formed cervix connected to the vagina. Unicornuate uteruses may also have a second hemi-uterus, a smaller second cavity that is blocked from the vagina. Women with unicornuate uteruses often have a period and can maintain a pregnancy, but are at risk for premature delivery and breech birth, and often have to deliver via cesarean section.

Women who have developed a hemi-uterus may experience pain due to trapped blood during menstruation. A hemi-uterus is usually diagnosed with an ultrasound or other imaging, or a laparoscopy procedure.

Septate uterus

Women with a septate uterus usually have a normally shaped uterus that has developed a center septum wall, dividing the uterus into two cavities. Although a woman may still be able to have a regular period and maintain a pregnancy, she is at risk for recurrent pregnancy loss, premature labor, and delivering a baby in the breech position.

Additionally, if the septum wall blocks the vaginal septum, menstrual blood may become trapped in the upper vagina.

Symptoms of uterine anomalies

Most women with uterine anomalies do not experience symptoms and may not discover they have an abnormal uterus until they have a routine pelvic exam or an ultrasound.

When symptoms do occur, women may experience:

• Never having had a period
• Recurrent miscarriages or infertility
• Preterm labor or abnormal positioning of the baby during pregnancy or labor
• Pain when inserting a tampon
• Pain during sex
• Pain with menses

Additionally, a uterine anomaly can block menstrual blood from exiting the body due to incomplete development of the vagina or uterus. This usually causes monthly abdominal pain, with or without the presence of external bleeding.

Treatment of uterine anomalies

Uterine anomalies can be diagnosed with a physical exam, imaging test, or laparoscopy procedure (which allows the physician to use a laparoscope to view the inside of a woman’s uterus).

Many women with uterine anomalies do not require treatment. If pain, miscarriage, or infertility is an issue, a physician may recommend correcting the anomaly surgically. Most cases of uterine anomalies can be corrected through minimally invasive techniques, such as laparoscopy or hysteroscopy.

In the instance of a unicornuate uterus, an obstructed hemi-uterus can be removed if the other side of the uterus is intact and functional. A dividing uterine septum can usually be removed as well to open up the uterus.

Women who are at risk for preterm delivery or late pregnancy loss due to a uterine anomaly may need a stitch to be placed in the cervix (called a cervical cerclage) to prevent premature dilation.