Last reviewed by Editorial Team on August 13th, 2018.
What is Bicornuate Uterus?
Definition: This type of uterus is shaped into two horns, or chambers instead of one. It is also referred to as a heart-shaped uterus. A bicornuate uterus forms during the embryonic stage of development, which is usually at five weeks of gestation. There are different forms of severity of this type of uterus that ranges from a partial bicornuate to a full bicornuate. With a partial bicornuate only the top portion dips into the chamber and with a full bicornuate the complete top portion folds down to create two chambers. The degree of malformation is a very important fact as far as childbirth and pregnancy are concerned.
It is estimated that approximately 0.1 to 0.5 percent have this type of uterus but as many cases go undetected this could be an underestimation. Having a bicornuate uterus is one of more common forms of congenital uterine anomaly. If you become pregnant and it is found that you have a bicornuate uterus, it is important to be extra cautious during your pregnancy and follow the instructions of your gynecologist to help avoid any serious complications.
How a Bicornuate uterus forms
As mentioned, this happens at approximately five weeks gestation and starts out near your kidney as two separate structures called horns. They then migrate down into your pelvis as these two horns fuse into one. The area of fusion is called a septum, which divides the two and then is reabsorbed to make an intrauterine cavity that is normal. Unfortunately, this normal progression does not occur, which is when you have a uterine abnormality. In this case, it is a bicornuate uterus. It is a true bicornuate uterus if the two horns migrate down but do not fuse completely to make the normal uterus.
Symptoms of Bicornuate Uterus
Although some women may experience symptoms that could indicate a bicornuate uterus it is rare to have any symptoms. If there are symptoms they can include:
- Abdominal pain
- Irregular or heavy menstrual periods
- Painful ovulation
If you are experiencing any of these symptoms you should see your gynecologist and ask for an ultrasound to rule out a possibility of having a bicornuate uterus.
During the embryonic stage of development the fallopian tubes and the Mullerian ducts, which become the ovaries do not fuse properly. It causes the upper part of your uterus to fold inward and the bottom part of your uterus to appear normal. It causes a malformed uterus that is shaped like a heart.
Pictures of Bicornuate Uterus
Picture of Bicornuate uterus
Picture : Normal vs Bicornuate uterus
Most women do not even realize that they have this type of uterus until they try to become pregnant. A bicornuate uterus is not definitely related to infertility but the shape can make getting pregnant challenging. If you do become pregnant it can put you in a high-risk category. It depends on how severe a malformation you have. If it is a moderate degree it may not even affect your pregnancy but if it is a severe malformation it could cause problems.
- You will also be told that you may have difficulty conceiving and you are at a high risk of having a miscarriage with a sixty-three percent chance. The reason that there is a high chance of you having a miscarriage is because there is not enough room for the baby to grow there. In a normal uterus it can expand with a growing baby but with a bicornuate uterus the septum area cannot expand enough to accommodate the growth. If the baby does plant itself in the largest part of the uterus it will have a chance of growing to become a full-term baby.
- There is also a fifteen to twenty-five percent chance of having a pre-term delivery, or premature baby.
In a partial bicornuate there is a forty to fifty percent chance of the baby being born breech because with two chambers there is less room than in a uterus that is shaped normally. The baby may find it difficult to comfortably fit in a head-down position.
- It could also cause fetal growth retardation, which means having less than ten percent of fetal weight according to the baby’s gestational age but it rare that this happens.
- Sometimes the baby will have other birth defects.
- Trapped or retained placenta
How is Bicornuate Uterus Diagnosed?
If it has not been detected earlier this type of uterus will be detected during the initial ultrasound during pregnancy. Having an MRI can also detect a bicornuate uterus. When your gynecologist does a pelvic exam they may also be able to detect it.
Some gynecologists will suggest that you have reconstructive laparoscopic surgery but what actual treatment, if any, will be used depends on the individual. Because the pregnancy can be risky some gynecologists will opt to do a cervical cerclage. This is when a stitch is placed in your cervix to prevent premature dilation. With premature dilation you could have a miscarriage or have a premature baby.