Bicornuate Uterus: Causes, Symptoms, Fertility, and Pregnancy Risks

What Is a Bicornuate Uterus?

"Bicornuate uterus" is the name given to a congenital condition in which the upper uterus is divided into two halves by an indentation. This results in a shape that resembles the heart, which is why it is also called a heart-shaped uterus.

During normal development, the uterus develops from the complete fusion of two Müllerian ducts in the fetus. If the fusion does not take place fully, the bicornuate uterus is formed with two uterine horns sharing a common cavity below.

The degree of separation varies from mild to severe. Women with a mild case of a bicornuate uterus might not experience any reproductive issues. In contrast, for those who have a greater degree of separation, there is always an increased possibility of experiencing pregnancy complications.

The bicornuate uterus differs from other congenital uterine anomalies, such as the septate, unicornuate, didelphys, and arcuate uterus. Given that the treatment options for these conditions differ, a proper diagnosis is crucial before planning a pregnancy or going for fertility treatment.

What Causes a Bicornuate Uterus?

A bicornuate uterus develops before birth and is present throughout life. It does not result from diet, exercise, infections, or lifestyle factors.

During foetal development, the two Müllerian ducts unite to form a single uterine cavity. When there is an incomplete union, the uterus develops as a twin-horned uterus, with two upper horns rather than a single uterine cavity.

The precise cause of such an incomplete union is not known. Most cases are sporadic, though there could be a genetic or developmental component. Some women with a bicornuate uterus also have kidney or urinary system disorders since they develop at a similar time during foetal development.

What Are the Symptoms of a Bicornuate Uterus?

Many women with a bicornuate uterus do not realise they have the condition until they undergo imaging during pregnancy or are evaluated for recurrent miscarriage or infertility. In fact, some women never develop noticeable symptoms. Others may develop menstrual symptoms and reproductive issues; however, these are not exclusive to a bicornuate uterus.

• Irregular or Painful Periods

Women with a bicornuate uterus may have painful periods, heavy bleeding during periods, or periods that last longer than normal. In some instances, irregularity in the structure of the uterus can contribute to these symptoms. However, similar symptoms are associated with conditions such as uterine fibroids, adenomyosis, and endometriosis. An examination by a physician is required to determine the underlying condition.

• Recurrent Miscarriages

Repeated loss of pregnancy is one of the early symptoms of a bicornuate uterus. This condition is characterised by less space for the implantation and development of the embryo, hence putting women at risk of having miscarriages. However, many women can carry normal pregnancies despite these complications.

• Pelvic Pain

Women may experience occasional pelvic pain or discomfort, especially during their menstrual periods. Although pelvic pain is not always associated with the condition of a bicornuate uterus, symptoms must be checked to ascertain that there are no other gynaecological disorders.

• Pain During Intercourse

Women may sometimes experience pain during deep penetration due to the abnormal pelvic structure. Ongoing pain during intercourse should always be assessed by a gynaecologist to identify the underlying cause.

• Why Some Women Have No Symptoms

A large number of women with a heart-shaped uterus remain symptom-free throughout their lives. The condition is often detected incidentally during routine pelvic ultrasound, infertility evaluation, or prenatal imaging. The absence of symptoms does not necessarily predict how future pregnancies will progress.

How Does a Bicornuate Uterus Affect Fertility?

Concerns about bicornuate uterus fertility are common among women who have been diagnosed with the condition, especially because it brings into question whether one will be able to conceive with a bicornuate uterus. Nevertheless, one can be assured that the issue does not affect ovulation, egg production, the fertilisation process, or sperm motility.

Many women conceive naturally without any fertility drugs. Nonetheless, even though conception might happen naturally, maintaining the pregnancy can at times be challenging due to the uterine structure.

Various factors affect fertility, and these include:

• The degree of uterine partition
• Age of the woman
• Quality of eggs
• Sperm quality
• Other reproductive complications such as endometriosis or polycystic ovary syndrome

In instances where women encounter problems in conceiving, it is important to carry out an analysis of fertility because factors other than the bicornuate uterus may contribute to infertility. Evaluation of both partners is essential in determining the presence of other factors contributing to infertility, thereby facilitating the proper course of treatment.

A bicornuate uterus does not automatically make conception impossible, although having one makes you more susceptible to some problems in pregnancy. There are many cases of women who have conceived naturally despite having a bicornuate uterus fertility problem.

Pregnancy Risks with a Bicornuate Uterus

A bicornuate uterus pregnancy is considered higher risk because the divided uterine cavity may affect foetal growth and positioning. Regular antenatal care and consultations can lead to better pregnancy outcomes.

• Miscarriage

Women with a bicornuate uterus are more likely to experience miscarriages than those who have a normally formed uterus. Scarcity of space within the uterus and implantation in an unusual place might be the reason for miscarriage, but many women carry their pregnancies without any problems.

• Preterm Labour and Preterm Birth

When pregnancy is progressing, the smaller cavity of the uterus may provoke contractions of the uterus sooner than expected, leading to preterm labour. Regular prenatal consultations will help to recognise the signs of premature birth.

• Breech Presentation

The unusual structure of the uterus may make it difficult for the foetus to move to the head-down position. Breech or transverse presentation is therefore more common.

• Foetal Growth Restriction

Some babies may have restricted growth if the available uterine space limits normal development. Serial ultrasound examinations help monitor foetal growth throughout pregnancy.

• Cervical Insufficiency

Some women may develop cervical shortening during pregnancy, increasing the risk of second-trimester pregnancy loss or preterm birth. Cervical length monitoring allows early detection, and selected women may benefit from cervical cerclage.

• Delivery Planning and Caesarean Birth

The choice of delivery will be based on the baby's position, gestational age, and the mother’s health. Even though some women with a bicornuate uterus can opt for natural delivery, some others may have to resort to elective caesarean delivery.

How Is a Bicornuate Uterus Diagnosed?

A bicornuate uterus may be diagnosed during investigations of infertility or recurrent miscarriages, and in pregnancy ultrasound scans. The accurate diagnosis of the condition is critical since it resembles other congenital uterine anomalies like the septate uterus.

Common diagnostic tests include:

• Pelvic ultrasound: Usually the first imaging test performed.
• Three-dimensional ultrasound: Provides accurate visualisation of the uterine cavity and its outline.
• Magnetic Resonance Imaging (MRI): Used to differentiate a bicornuate uterus from other uterine anomalies.
• Hysterosalpingography (HSG): Evaluates the uterine cavity and fallopian tubes with the help of contrast medium and X-rays.
• Hysteroscopy or laparoscopy: Can be recommended in some patients to gain further information.

After the diagnosis has been made, the health care professional will review the patient's symptoms and reproductive history, along with her plans regarding pregnancy.

Treatment Options for a Bicornuate Uterus

Not every woman who is diagnosed with a bicornuate uterus requires treatment. Treatment will depend on symptoms, previous pregnancy history, and future intentions. Those who are asymptomatic and have had a successful pregnancy in the past generally do not need treatment.

Women intending to conceive should consider preconception counselling to discuss potential risks and optimise overall health before conception.

1. Conservative Approach

The majority of pregnant women may benefit from close monitoring rather than surgery. The conservative approach is comprised of:

• Regular gynaecological examination
• Early detection of pregnancy
• Antenatal monitoring
• Regular ultrasounds to monitor the development of the fetus
• Cervical length monitoring for women who are at risk of cervical insufficiency

Early diagnosis of complications associated with pregnancy can allow for quick action and better outcomes.

2. Surgical Treatment

Surgery is recommended for select patients who experience poor reproductive outcomes due to the abnormality in the bicornuate uterus. The most popular technique of surgical management is Strassman metroplasty, which involves reconstruction of the uterus to create one uterine cavity. It is suitable for women who undergo recurrent miscarriages or preterm births in the second trimester.

Possible risks associated with the operation are bleeding, infection, adhesion formation, and possible complications during pregnancy.

Can IVF Help Women with a Bicornuate Uterus?

A bicornuate uterus generally does not interfere with conception; hence, IVF is not generally suggested for a bicornuate uterus alone. Many women have been able to conceive naturally without any assisted reproductive technology.

Nonetheless, IVF can be considered if other reasons exist for infertility, such as:

• Blocked fallopian tubes
• Infertility related to the male partner
• Low ovarian reserve
• Anovulatory disorder
• Endometriosis
• Unexplained infertility

Although IVF can lead to pregnancy, it cannot change the shape of the uterus. Thus, the risks that accompany a bicornuate uterus pregnancy can persist despite the success of IVF. Women undergoing IVF should receive individualised care from fertility specialists and obstetricians to optimise pregnancy outcomes.

Conclusion

A bicornuate uterus is one of the more common congenital uterine anomalies and results from incomplete fusion of the Müllerian ducts during fetal development. Although the uterus has a characteristic heart-shaped uterus appearance, its impact on fertility and pregnancy varies widely among women.

Pregnancy outcomes vary from one woman to another. Some women experience uncomplicated pregnancies; however, other women might encounter certain difficulties like miscarriage, premature birth, or even malpresentations in the fetus. Early diagnosis helps in planning appropriate antenatal care for the expectant mother and the developing fetus.

Surgical repair of the bicornuate uterus is not always required. The surgical correction comes after recurrent pregnancy loss. Without going through surgery, many women can carry a bicornuate uterus pregnancy to term and deliver healthy babies safely.