Uterine Abnormalities During Pregnancy - Classification, Symptoms & Treament

Uterine Abnormalities

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Although unseen and sometimes unacknowledged, the uterus tends to play a rather significant role in your life. It is where your little one grows and gets the necessary protection and nourishment until he is ready to emerge into the world. And, it becomes important for you to learn as much as you can about uterine abnormalities and how they can hamper your prospects of motherhood. It’s because understanding different types of uterine abnormalities will help you understand your situation and make an informed medical intervention decision if it is an option.

Facts About Uterine Abnormalities:

As strange as it may sound, uterine abnormalities are not rare. Hence, it is crucial you understand a few things about these anomalies.

Uterine abnormalities don’t exhibit many signs or symptoms. Remember, your uterus plays a role only when you get pregnant or are trying to conceive. Hence, until such time, you may not realize that you have a uterine abnormality. Of course, you may experience pain or irregularity in your menstrual period before the anomaly comes to light, but you will disregard these instances as normal menstrual discomfort and carry on with life. You will never associate the pain and irregularity with uterine abnormalities.

Many uterine abnormalities may not even cause any complication with your pregnancy. For example, fibroids are one of the most common uterine problems. In many pregnancies, fibroids do not harm the growing fetus or create irresolvable complications during pregnancy.

Certain uterine abnormalities may result in miscarriages or preterm births. A doctor can analyze these abnormalities only when you are trying to conceive actively, or you fall pregnant. This is the reason preventive, and precautionary measures rarely become solutions for uterine conditions.

Some uterine abnormalities present conditions that need medical intervention to improve your chances of having a healthy, uncomplicated pregnancy.

[ Read: Causes And Risks Of Preterm Labor ]

What Are Congenital Uterine Abnormalities?

Congenital uterine abnormalities are rare, but they do occur. Less than 5% women have congenital uterine anomalies [1]. A congenital condition is typically present at birth. So, if you have a congenital abnormality of the uterus, it means you were born with the defect. Usually, your uterus develops while you are growing in the womb as two sections. These two parts fuse before birth.

Fascinating congenital abnormalities of the uterus are müllerian duct anomalies. Between the 6th and 11th week of pregnancy, the müllerian ducts fuse to form the fallopian tubes, uterus, proximal two-thirds of the vagina, cervix in a female fetus [2]. Sometimes this fusion doesn’t occur properly, leading to defects in the internal reproductive organs. Usually, these abnormalities are linked to the working of the ovaries or the external genitalia. In most cases, the anomalies become apparent with the onset of puberty. Before puberty, the abnormalities of the internal reproductive organs are not visible or noticeable. Usually, gynecologists diagnose the problem after a young woman approaches them for menstrual disorders.

Can Congenital Uterine Anomalies Affect Pregnancy?

Whether uterine defect will cause pregnancy-related issues or not depends primarily on the type of abnormality. In most cases, women with uterine anomalies can conceive naturally, and they won’t even realize that they have a defective uterus. These abnormalities may, however, determine whether the pregnancy will continue full term or the woman will have a miscarriage.

Remember uterus is another name for your womb. So it goes without asking that any defect of the uterus will have a profound effect on your pregnancy. Nevertheless, there are also a few uterine conditions that may not have a significant impact, and if you have one of these conditions, you may still be able to deliver a healthy baby with or without medical intervention. This said it is more common for a pregnancy to develop problems in case of uterine anomalies, or the following issues may further aggravate due to the defects:

1. Premature Birth:

Most uterine conditions can result in a premature birth. Premature birth is when delivery happens too early, before 37 weeks of pregnancy. Preterm births pose health risks to the newborn as his immunity is not entirely developed to survive outside the womb. Also, in some babies, the lung development may not be complete. If you have a preterm baby due to a uterus-related defect, he will require specialized neonatal care until the neonatologist deems it necessary.

2. Birth Defects:

Birth defect in infants is another common result of uterine abnormalities. This may lead to various kinds of defects that could cause problems in the overall health or development of the baby. Sometimes, these defects could relate to physical or psychological development of the unborn baby.

3. Slow Fetal Growth:

Uterine anomalies may cause your baby to develop slowly inside the womb as well as post birth. Some of the most common developmental issues with infants occur when a woman has a uterine defect. Due to an abnormal uterus, your baby may not get the nourishment it requires for optimal growth.

4. Breech Position:

Uterine anomalies may result in the baby going into the breech position inside the womb. This position is when your baby’s bottom or feet are facing down instead of the head. Such pregnancies do not have a significant impact on the viability of the fetus but may require a planned caesarean. Also, sometimes, such pregnancies may not reach full term.

5. Miscarriage:

Miscarriages are the most common result of uterine anomalies. Most women with abnormalities of the uterus will encounter one or more miscarriages. As a matter of fact, it is often after a miscarriage that some of these uterine anomalies become significantly visible as they may not present any symptom prior to the pregnancy and subsequent miscarriage [3].

[ Read: Causes And Symptoms Of Miscarriage ]

Causes Of Müllerian Duct Anomalies:

Müllerian duct anomalies are congenital abnormalities. Hence, if you have it, in all probability you were born with the defect. As stated earlier, these defects affect the uterus, vagina, cervix, and fallopian tubes, and hence, you may find it difficult to conceive and have a healthy and normal pregnancy. To understand what causes these complications, it is important first to have knowledge of normal müllerian tract development in the embryo.


When the human embryo develops into a fetus, it forms two tracts side by side. These tracts are known as the Wolffian (mesonephric) and the Müllerian (paramesonephric) tracts. The Wolffian (mesonephric) ducts go on to form the prostate, seminal vesicles, and vas deferens if it is a male embryo. This tract persists in the female embryo, but either remains non-functional or gets wasted due to the lack of testosterone, the male hormone.

At about 8th to 10th week of gestation, the male embryo also secretes an anti- müllerian hormone (AMH), which inhibits the development of the Müllerian (paramesonephric) tract. Just like the female embryo may still have the Wolffian tract as non-functional, the male fetus may still have the müllerian duct in a non-functional state, or it forms into a non-functioning homolog of the uterus.

In a female embryo, there is no production of the AMH. The müllerian ducts develop into the normal female reproductive system, and typically the Wolffian tract dissolves. However, if the Wolffian tract persists long enough to form a kind of a template in the female embryo, complications related to the uterus or kidneys will develop in the female fetus.

In the case of normal development of the female reproductive organs, a portion of the müllerian duct goes on to fuse and form the uterovaginal primordium, a Y-shaped tube. Also known as the UVP, the caudal part of the tube forms the upper portion of the vagina, cervix, and the uterine fundus while the cephalic portion forms the fallopian tubes. When there is a minor or major disruption in this process, uterine anomalies tend to develop. This is typically when the müllerian ducts do not fuse completely.

Classification Of Uterine Anomalies:

Usually, müllerian duct fusion takes place seamlessly and in a symmetric manner. This may not be the case always because of environmental and genetic reasons, and it leads o various uterine anomalies. The problem here is that most of these anomalies do not show any signs or symptoms until the woman tries to conceive. This is the reason why there is a lot of debate on classifying them.

While there isn’t a universal classification of müllerian duct abnormalities, the most widely accepted classification is by the American Fertility Society. This classification is as follows:

[ Read: Effects Of A Bicornuate Uterus On Pregnancy ]

Category 1 – Agenesis And Hypoplasia:

This category of uterine abnormality covers agenesis of the various parts of the uterus, cervix, and the fallopian tubes. Most women who suffer from Category 1 agenesis or extreme hypoplasia may suffer from severe fertility-related issues, but may still have relatively normal hormone cycles. Some women with this agenesis or hypoplasia have a condition called infantile uterus. This condition occurs due to hypopituitarism problems and is related to the müllerian duct. Hence, doctors can treat with the help of gonadotropins and menotropins which aid in inducing ovulation.

Agenesis occurs when the vagina does not form properly or is too short. Also, the uterus may be quite small or it may be completely missing. The condition becomes a concern when the woman goes well past her puberty but does not start her menstrual cycles. Women with this rare condition can have kids just through surrogacy.

Category 2 – Unicornuate Uterus:

The Category 2 uterine anomaly deals with the uterus unicornis and can be with or without an anlage. If this anomaly is without an anlage, it is most likely a result of complete degeneration or failure of the müllerian duct. On the other hand, if anlage is present, the uterus is capable of supporting pregnancy but only for about 20 weeks. After this stage, the uterus tends to rupture. Doctors may recommend a hemi-hysterectomy to prevent this from occurring.

Typically, a unicornuate uterus is rather an uncommon condition, restricted to about 5% of total uterine anomalies. This condition, however, sees the maximum pregnancy wastages. Most women with unicornuate uterus also have a renal defect. A unicornuate uterus is half the size of a normal uterus. The condition is also known as one-horn uterus because of its shape.

Category 3 – Uterus Didelphys:

The Category 3 uterine anomalies occur in about 1 in 2000 women. Again it is a rare condition, and it occurs due to duplication of the müllerian tract. It is prudent to remember that an actual duplication, with two separate vaginas, cervices, and uterine fundi, is a rare condition. Typically, this condition occurs as a top to bottom split of the müllerian duct. Women with this type of uterine abnormality almost always have a kidney abnormality too.

The rarest and also the most problematic, uterine didelphys can lead to miscarriages and breech babies. Because there is a second uterus, there is a higher likelihood of the mother carrying twins if she becomes pregnant with this anomaly. If this happens and the pregnancy is viable, the twins are completely separate, developing individually in different hemi uterus. These twins may be born hours, days or even weeks apart.

[ Read: Shoulder Presentation ]

Category 4 – Bicornuate Uterus:

The Category 4 uterus bicornis is a more common uterine defect. Like Category 2 and Category 3 anomalies, this uterine abnormality is also a result of the müllerian duct not fusing properly to form a unified uterus. This anomaly is further classified as bicollis – two cervices, or unicollis – one cervix.

While it is a uterine anomaly, the bicornuate uterus does not pose fertility-related issues. Women with this anomaly, however, commonly have breech babies. Also, there is an increased risk of miscarriage in women who conceive with the bicornuate uterus.

Category 5 – Septate Uterus:

The Category 5 uterine anomaly, the septate uterus, is a result of a proper fusion of the müllerian ducts, but a faulty resoprtion. The inner partition that separates the two müllerian tracts does not dissolve either partially or wholly. This midline septum lacks protein Bcl-2 that protects the other parts of the uterus. Whether the septum exists partially or entirely, the septate uterus poses maximum pregnancy-related issues, with completely septate uteri showing about 90% pregnancy wastage. Treatment, however, is possible by a simple endoscopic lysis of the septum.

Category 6 – Arcuate Uterus:

Known as uterus arcuatus or arcuate uterus, this type of uterine anomaly is typically nothing to be too worried about. In fact, an arcuate uterus is simply a slight variation of a normal uterus. The uterus has a slight heart-shaped appearance, and this happens when the müllerian tracts fail to fuse or have a dysfunctional septum, but to a small degree.

Category 7 – T-Shaped Uterus:

The T-shaped uterus in female infants is a result of the mother consuming diethylstilbestrol (DES) to do away with a risk of miscarriage. Studies indicate that about 69% of female offspring of women who consumed DES during their pregnancy developed abnormal uterine cavities have a T-shape with or without dilated cornua. The uterus in these cases tends to be hypoplastic and prone to cervical incompetence. This results in midterm loss of the fetus. These female infants are also susceptible to other histological abnormalities and are more prone to cervical or vaginal cancer at an early age.

Only about 34% pregnancies with DES uterus go full term, and about 38% pregnancies end in a miscarriage. Ectopic pregnancies are also common in DES uterus [4].

Symptoms Of Congenital Uterine Anomalies:

Congenital uterine anomalies are present at birth, but they rarely exhibit any sign or symptom. Some women may experience pain during their menstrual period, but that is not always indicative of a congenital defect in the uterus. Most of these abnormalities come to the forefront only after recurrent pregnancy loss or infertility problems.

[ Read: Infertility In Women ]

What Are Uterine Fibroids?

Fibroids are a common uterine abnormality. These are benign muscle tissue growths on the inner walls of the uterus. Benign means non-cancerous and usually harmless. Unlike müllerian anomalies, which are present at birth, fibroids occur later in life.

In most cases, these growths are relatively small and may not pose any pregnancy complication or any other complication. However, if you have large fibroids then you may be at a risk of developing certain complications, which are as follows:

  • Fibroids can cause infertility-related issues
  • One of the common consequences of fibroids is preterm labor. If your labor starts before the 37th week of gestation, it is preterm labor
  • Fibroids can cause your baby to go into a breech position. This may necessitate a C-section for yours and your baby’s safety
  • Placental abruption is a serious condition that may result due to fibroids. When you have placental abruption, your placenta separates from the wall of the uterus before birth, and this affects the growth and development of the fetus as it doesn’t get nourishment
  • Miscarriages are common in women who have large fibroids
  • There is also a risk of heavy bleeding after giving birth [5]

Symptoms Of Uterine Fibroids:

When you have fibroids, there could be certain signs and symptoms that you would experience. Keep an eye out for the following:

  • Heavy menstrual bleeding
  • Anemia
  • Persistent pain in your abdomen
  • Pain during and after sexual intercourse
  • Pain while urinating and frequent urination
  • Pain in the lower back
  • Pain at the back of the legs
  • A large stomach that may come across as the woman being pregnant or having gained too much weight
  • Pressure in the lower abdomen [6]

Treatment of fibroids typically involves giving you pain killers to help you alleviate the pain in the abdomen or back. However, if your fibroids are big enough to create problems with your pregnancy, your medical practitioner may recommend surgical removal of fibroids through a myomectomy.

[ Read: Uterine Fibroids During Pregnancy ]

What Are Uterine Scars?

Also known as Asherman syndrome, uterine scars are scars or scar tissues that line the walls of the uterus. These scar tissues damage the endometrial lining of the uterus. They develop due to an infection in the uterus or surgical procedure, such as dilation and curettage (D&C).

Uterine scars may or may not manifest symptoms, but can result in pregnancy-related problems, such as infertility, repeated miscarriages, and premature birth. The good news is this is one uterine abnormality that a doctor can treat. This is because uterine scars are acquired and not congenital in nature. Hysteroscopy can help remove the scar tissue from your uterus and ensure you enjoy the joys of motherhood.

How Are Uterine Anomalies Diagnosed?

Most uterine anomalies do not show significant signs or symptoms. It is only when a woman with these abnormalities tries to conceive or suffers pregnancy complications that doctors diagnose them. The following procedures help in the diagnosis of uterine anomalies:

1. Vaginal Ultrasound:

A vaginal ultrasound is an internal ultrasound that uses sound waves to capture images of your vagina and other parts of the uterus. To accurately diagnose uterine defects, a vaginal ultrasound is imperative as an abdominal ultrasound over the belly will not clearly indicate the state of your womb.

[ Read: Ultrasound During Pregnancy ]

2. Hysterosalpingogram:

This test requires insertion of a dye into your cervix. After that, the doctor will take an X-ray. It allows the diagnosing physician to evaluate your uterus, cervix, and fallopian tubes. A doctor performs this test only if you are not pregnant.

3. Magnetic Resonance Imaging (MRI):

This test uses large amount of magnetic and radio waves to evaluate your uterus. Many healthcare practitioners believe MRI is the most accurate way of identifying a majority of uterine anomalies. Again, your doctor will perform an MRI only if you aren’t pregnant.

4. Sonohysterogram:

If a regular ultrasound does not provide clear images of your uterus or the results are inconclusive, the doctor may suggest sonohysterogram. For this test, the sonographer will insert salt water into your uterus through the cervix. After that, he will use ultrasound to get images of your uterus. Doctors perform this test just on women who are not pregnant.

[ Read: Transvaginal Scan During Pregnancy ]

Treatment For Congenital Uterine Anomalies:

Unfortunately, there are no surgical procedures to treat congenital uterine anomalies. However, the treatment protocol often depends on the reproductive history of the woman. It wouldn’t be wrong to state that in most cases, treatment is case-specific.

Among the different types of congenital uterine abnormalities, the septate uterus may still be treated with surgery, but there are no surgical options for other defects, including bicornuate, unicornuate, and didelphic uteri.

Things To Consider:

Treatment for congenital uterine anomalies is not always possible. While there are some treatment options, these do not apply to all types of uterine abnormalities. In some cases, the treatment methods can pose further risks. For instance, if the doctor has to remove the septum surgically in the case of a septate uterus, the endometrial lining of the uterus can get affected, and this may further have a negative impact on a woman’s fertility.

Hence, if there is a treatment for your uterine anomaly, weigh the risks and advantages before you opt for it. Speak to your doctor and also use the Internet to educate yourself so that you can make an informed decision.

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