Unicornuate Uterus and Pregnancy - Causes, Symptoms & Treatment

Getting Pregnant With Unicornuate Uterus

Medically Reviewed By
Dr. Sabiha Anjum (Gynecologist/Obstetrician)
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A unicornuate uterus is a rare congenital uterine malformation that around 0.6% of the infertile population and 0.3% of the whole population are diagnosed with. Although there have been successful pregnancies in spite of having a unicornuate uterus, there are certain risks attached to it. If you have been diagnosed with the condition and need information on it, you have reached the right place. In this article, we shall touch upon some primary points about the condition and provide insights into the causes, diagnoses and treatments to manage a unicornuate uterus to enable you to get pregnant. Read on to know more.

What Is Unicornuate Uterus?

A unicornuate uterus is a congenital uterine abnormality, in which the uterus is smaller than a typically-sized uterus and has only one functioning fallopian tube. If the other side of the uterus is present, it may be a rudimentary horn. At times, it may be connected with the rest of the uterus or may contain a functional endometrium. In certain cases, the uterus may develop a smaller offshoot called a Hemi-uterus.

What Causes Unicornuate Uterus?

A unicornuate uterus is caused due to an abnormal müllerian duct or paired duct of the embryo. It is a congenital condition, i.e. women are born with it.

Symptoms of Unicornuate Uterus

There could be no symptoms when there is a hemi-uterus with a small cavity and a functional endometrium. It is asymptomatic because the cavity forms a connection with the uterus and the vagina, and drains out the menstrual fluid. So, there is no abdominal/pelvic pain or discomfort. This occurs in 65% of women, and the condition may remain undetected until the woman faces difficulty in conceiving. In such cases, unicornuate uterus treatment becomes delayed.

But, in many cases the horn does not connect to the uterine cavity, resulting in the following symptoms:

  • Chronic Pelvic or Period-Related Abdominal Pain: This can occur in cases where the functioning horn is solid and isolated from the rest of the uterus. The pain occurs because of a build-up of menstrual fluid that cannot drain out through the vagina.
  • Hematometra: This is the accumulation or retention of blood in the uterus because of its inability to drain out fluids. The symptoms are cramping pain during periods in the lower abdomen and pelvic midline, frequent urination, and urinary retention. Women in pre-menopause may also report abnormal bleeding or no menstruation at normal cycles. The build-up of blood may also cause low blood pressure or a vasovagal issue. However, women in menopause may be asymptomatic.
  • A history of infertility.
  • Premature birth, miscarriage, and breech baby.


Diagnosis of Unicornuate Uterus

This condition remains undiagnosed until a woman suffers from pregnancy complications like a history of infertility, repeated miscarriages, or premature delivery.

There are some tests that can help detect the condition and facilitate timely treatment:

  • Infertility and/or Regular Pelvic Tests: Unicornuate uterus may be suspected with the help of these tests. Detection is usually rare in these tests.
  • Imaging: A normal ultrasound often fails to diagnose a unicornuate uterus. An MRI, which is three-dimensional sonography, has better results.
  • Laparoscopy: Laparoscopy can help confirm the condition by allowing a thorough check-up of the uterus.
  • Hysteroscopy: This is a process in which a miniature telescope is inserted via the cervix to view the uterus for diagnosis or treatment of certain conditions. This can also detect a unicornuate uterus.

Now, let’s take a look at how unicornuate uterus can affect pregnancy.

Unicornuate Uterus and Pregnancy

Reproductive complications are common in women with a unicornuate uterus. Pregnancy in unicornuate uterus women is difficult because usually only one fallopian tube functions in this situation. Even if they become pregnant unicornuate uterus involves the following risks:

  • Miscarriage: There maybe foetal demise and stillbirth because of the abnormal shape of the uterus and inadequate blood flow to the uterus and the placenta.
  • Premature Birth: Women with unicornuate uterus may go into early labour because the baby outgrows the uterine space that is smaller than usual. This happens in the first stages of pregnancy. It increases the chances of a breech birth as well, where the baby is born ‘bottom first’ instead of the normal ‘head first’. This can lead to a cesarean (C-section) instead of a normal delivery.
  • Ectopic Pregnancy: Women with unicornuate uterus may witness an ectopic pregnancy. This occurs when a fertilized egg implants outside the uterus, typically in the fallopian tube. Unfortunately, ectopic pregnancies must be terminated as the pregnancy cannot survive outside the uterus.
  • Heavy Bleeding: This could pose a life threat because of a premature rupture of membranes during the first or second trimester.
  • Intrauterine Growth Retardation: Here, the newborn may be smaller in weight and size.
  • Placenta Previa: When a woman conceives, the placenta usually attaches to the upper part of the uterus, leaving the cervix free. In placenta previa, it attaches to the lower part of the uterus, spreading to the entire or part of the cervix.
  • Placental Abruption: Here, the placenta gets detached from the uterus, usually after the 20th week of pregnancy. If it goes undetected, it may result in a stillborn or premature baby.
  • Intrauterine Foetal Demise: The condition can lead to the demise of the foetus or stillbirth.
  • Abdominal Pain and Collapse: Detection of the condition may be delayed in spite of the advanced technology, which could result in collapse.

With the risks mentioned above, it is clear that a unicornuate uterus affects fertility in women. Let’s find out how.

Does Unicornuate Uterus Have Any Impact on Fertility?

A unicornuate uterus causes significant gynaecological and obstetrical complications. This has a major impact on fertility. Women are rarely able to conceive when there is a rudimentary horn. Even if they manage to conceive, there are various risks involved. For example, uterine rupture during the first or the second trimester could trigger heavy bleeding and pose a threat to the mother as well as the foetus.

Here’s the rate at which the condition can affect the fertility in women:

  • Live birth – 29.2%
  • Prematurity – 44%
  • Ectopic pregnancy – 4%
  • First-trimester abortion – 24.3%
  • Second-trimester abortion – 9.7%
  • Intrauterine fetal demise – 10.5%

Although there are ways to treat fertility, treating infertility due to a unicornuate uterus may be difficult, mostly because it is a congenital condition. However, there are treatments that can allow you to manage the condition. Let’s find out how.

Unicornuate Uterus – Possible Treatments

The treatment of a unicornuate uterus is never fully effective because the uterus cannot be enlarged surgically. The surgical and non-surgical procedures given below are the most accepted methods to manage the condition:

  • Cervical Stitch or Cerclage: This treatment is often suggested for those cases that report a history of miscarriages, premature delivery and incompetent cervix due to a unicornuate uterus. In this procedure, the cervix is stitched and closed during pregnancy.
  • Laparoscopic Surgery: This treatment is conducted to remove an isolated hemi-uterus because it causes abdominal pain due to the accumulation of menstrual blood that cannot flow out.
  • Emergency Delivery Under Special Care: Pregnancy is possible in a non-communicating uterus, as explained earlier in the article. However, this poses greater risks to pregnant women and could involve an emergency situation because a smaller uterus may rupture by the end of the second trimester due to space constriction. Utmost care and caution should be taken to avoid risks to the mother and the baby. To avoid this, doctors recommend a laparoscopy to remove the isolated hemi-uterus.

Usually, no surgical intervention is recommended unless the endometrial tissue in the rudimentary horn causes pain or a pelvic mass. A solid non-functioning hemi-uterus also need not be removed surgically.

Finally, the type of treatment depends a lot on the variations in the unicornuate uterus.

Some of the variations are given below:

  • A rudimentary horn may or may not be present.
  • The horn may or may not connect to the rest of the uterus.
  • The size of the uterus can also vary.

As most conditions are not treatable, one may want to consider assisted reproduction if they have experienced one or more of the symptoms mentioned in the article above.

Unicornuate Uterus and Assisted Reproduction

One of the most accepted treatments for a unicornuate uterus is IVF with embryo transfer. eSET (elective single embryo transfer) can reduce the high risk associated with multiple pregnancies and a singleton pregnancy in women with a unicornuate uterus. If a miscarriage occurs repeatedly, surrogate motherhood can be considered.

This condition may be very complex, but the good news is that many women have given birth to full-term healthy babies. Complications can be managed and averted with careful and advanced medical care. Speak to a medical practitioner who can provide you with solutions or effective ways to manage the condition and have a baby.

References and Resources: Healthline, Verywellfamily

Also ReadList of 10 Different Types Of Pregnancy

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