A bicornuate uterus or commonly known as heart-shaped uterus is a uterine malformation characterized by uterus with two horns and separated by a septum. It is formed during embryogenesis. The upper part of the paramesonephric ducts does not fused properly.
This resulted to a bifurcated upper part and a unitary lower part of the uterus. Let us take a look at how the uterus is formed.
Uterus is formed at five weeks of gestation. It starts as a two separate structure (horns) near the kidney and gradually migrates down the pelvis wherein the two horns will fuse into one. The two horns will fuse in the septum area and will be reabsorbed to form a normal intrauterine cavity.
There are instances in which normal progression does not occur, which leads to bicornuate uterus. A bicornuate uterus is one of the most common congenital uterine anomaly. In the United States, one out of five women have bicornuate uterus.
Bicornuate Uterus Symptoms
A women with bicornuate uterus have any of the following symptoms:
- Irregular menstruation
- Heavy menstruation
- Painful ovulation
- Abdominal pain and cramping as exacerbated by a malformed uterus
The danger associated with bicornuate uterus
A woman with bicornuate uterus has a slim chance of becoming pregnant. If ever you become pregnant, you will be automatically categorizes as high-risk pregnancy. About 63% of women with bicornuate uterus who became pregnant experienced spontaneous abortion. There is also a 25% chance of having preterm pregnancy.
Image 1: Bicornuate Uterus
Picture 2: Normal vs Bicornuate Uterus
How to Diagnose a Dicornuate uterus?
A diagnosis of bicornuate uterus is suspected if the patient complains of constant painful menstruation, miscarriage, infertility, and abnormal bleeding.
To correctly diagnose the condition of the patient, an intubation of the uterus cavity is performed. This is done to detect the shape of the uterus and the anatomical structure of the bicornuate. An ultrasound of the pelvis is done to confirm the diagnosis.
- HSG (Hysterosalpingogram) – In this diagnostic procedure, the divided uterus is visualize. However, it is difficult to differentiate bicornuate from septate uterus because the uterine fundal contour is not visible 5.
- MRI (Magnetic Resonance Imaging) – This procedure shows a deep fundal cleft, which is actually helpful in confirming the diagnosis.
Causes of bicornuate uterus
There are several factors that can lead to the formation of bicornuate uterus. A bicornuate uterus is most likely to happen if you experience any of the following during the first trimester of pregnancy:
- Intoxication ( alcohol, drugs, nicotine, other harmful chemicals)
- Vitamin deficiency
- Infections (measles, influenza, syphilis, rubella, and toxoplasmosis)
- Stressful pregnancy
- Endocrine problems ( hyperthyroidism and diabetes)
- Fetal hypoxia
- Cardiac-related diseases
What are partial bicornuate and full bicornuate uterus?
With partial bicornuate uterus, only the top part of the uterus dips into the chamber. On the other hand, a complete top part folds down in full bicornuate thereby creating two chambers. The severity of uterus malformation can directly affect pregnancy and childbirth.
What are Bicornuate Uterus twins?
Bicornuate uterus twins are twin pregnancies in the separate horns of the uterus. It is a rare case and usually an embryo transfer or in vitro fertilization is recommended. There will be risks involved and the couple should be informed and counselled about the risk.
Bicornuate uterus vs Septate uterus
Bicornuate uterus (BU) and septate uterus (SU) are used interchangeably, but these two terms are totally different. If you have bicornuate uterus, you are prone to preterm birth, miscarriage on the second trimester of pregnancy, and a cervical incompetence. On the other hand, a woman with septate uterus is prone to recurrent miscarriage on the first trimester of pregnancy.
They differ in treatment approach. Bicornuate uterus does not necessarily require surgery. All you need is careful monitoring during pregnancy. The patient is put in bed rest to prevent the cervix from prematurely dilating.
For women with septate uterus, a septum resection surgery is required. The surgery is done to increase your chance of becoming pregnant. On the inside, the two looks the same, but they differ outside. Hence, the doctor should thoroughly visualize the outside structure of the uterus to come up with a correct diagnosis.
Bicornuate Uterus Treatments
If you don’t intend to get pregnant, then having bicornuate uterus will not affect you in any way. There is no health risk involved and you can go on with your usual day to day living. On the other hand, if you are planning to have children, then you are recommended to undergo reconstructive surgery, especially if you have been pregnant a few times before and all resulted to miscarriage.
A metroplasty is done to correct the structure of the uterus. An incision is made to separate the uterine cavity. Another vertical incision will be made to close the layer of the uterus. After a successful surgery, you will need to wait for the wound to completely heal before getting pregnant. It usually takes three to five months for the uterus to fully recover from the surgery.
The impact of bicornuate Uterus Pregnancy
- It will be difficult for women with bicornuate pregnancy to get pregnant. If ever you get pregnant, there is a possibility of miscarriage. A close monitoring during the entire pregnancy period is a must.
- More than 50% of women with bicornuate pregnancy experienced miscarriage.
- Preterm birth is possible, which can be very stressful for the mother and the child. Usually, the baby will be placed in an incubator. To increase the possibility of full-term labor, a progesterone shot is given. It should start from the early stage of pregnancy up to the 36 weeks. Due to hormonal imbalances during pregnancy, the level of progesterone is significantly reduced which is one of the reasons for preterm birth.
- Should you become pregnant, the doctor will encourage you to deliver your baby via caesarean section to prevent further complication during delivery. Women with bicornuate uterus will cause the baby to breech, which is extremely difficult when giving birth.
What is the Prognosis?
A woman with bicornuate uterus who becomes pregnant can go on with the pregnancy without complications if the uterine cavity is strong. If it is weak, then worst thing could happen such as premature birth or miscarriage. Many women are not aware that they have bicornuate uterus until something unusual takes place that warrants them to see their OB-GYNE.
Once bicornuate uterus is correctly diagnose and you become pregnant, the doctor will closely monitor your condition to prevent miscarriage, bleeding, and cervical incompetence. Miscarriage usually happens in the first trimester.
If miscarriage is bound to happen after 26 weeks of gestation, a caesarean section is performed to save the life of the baby. However, the baby will be closely monitored in the neonatal intensive care unit and will be incubated.
If the pregnancy goes on smoothly, the doctor will request an ultrasound to find out the fetal position. If the presentation is cephalic (head first), a normal delivery is possible. If the presentation is breech (buttocks or feet first), the baby is delivered via C-section. Many doctors advise the patient to deliver via caesarean section to prevent further complications. It is the surest way of looking after the welfare of the baby and the mother.