Uterine & Reproductive Tract Anomalies

Reproductive tract anomalies are differences in the way the uterus, cervix, vagina, or hymen develop before birth. They are sometimes called congenital anomalies or Müllerian anomalies.

These differences can involve the shape or structure of the uterus, the presence of more than one uterine cavity or cervix, or differences in the development of the vagina or hymen. Some are very minor, while others involve more significant changes in reproductive anatomy.

Many people with a reproductive tract anomaly have no symptoms at all, and the difference may not be discovered until a pelvic exam, ultrasound, or other imaging is performed for an unrelated reason. Others may experience symptoms such as:

Difficulty using tampons or having vaginal intercourse
Painful or absent menstrual periods
Pelvic pain
Recurrent pregnancy loss or certain pregnancy complications
Difficulty becoming pregnant, depending on the specific anatomy

Not every reproductive tract anomaly causes problems or requires treatment. What it means for your health depends on the type of anomaly, your symptoms, and whether you are planning a future pregnancy.

Abnormal Reproductive Tract Development (ASRM)

Uterine Anomalies

The uterus normally develops when two structures come together and form a single uterine cavity. If this process happens differently, the uterus may develop a different shape, size, or number of cavities. These differences are often called Müllerian anomalies.

Common uterine variations include:

Septate uterus: A band of tissue called a septum partially or completely divides the inside of the uterus. The outside of the uterus usually has a normal shape.
Bicornuate uterus: The upper portion of the uterus is divided into two sections, creating a heart-shaped uterus with a noticeable indentation along the outer surface.
Uterine didelphys: Two separate uterine cavities develop, usually with two cervices and sometimes with a vaginal septum as well.
Unicornuate uterus: Only one side of the uterus fully develops, resulting in a smaller, one-sided uterine cavity. A small amount of additional uterine tissue, called a rudimentary horn, may also be present.
Arcuate uterus: There is a slight indentation at the top of the uterine cavity. This is generally considered a normal variation in uterine shape and usually does not require treatment.

Many uterine anomalies cause no symptoms and are discovered unexpectedly during an ultrasound or other imaging. Others may become important when evaluating recurrent pregnancy loss, fertility concerns, or certain pregnancy complications.

Because some uterine shapes can look similar on a standard ultrasound, additional imaging such as a 3D ultrasound or MRI may sometimes be recommended to better define the anatomy.

Uterine Abnormalities (Natalie Crawford, MD, video)

Cervical & Vaginal Anomalies

Differences in reproductive tract development can also affect the cervix and vagina. These may occur on their own or together with a uterine anomaly.

Examples include:

Duplicated cervix: Some people are born with two cervices, most commonly in association with uterine didelphys. Both cervices may need to be considered during cervical cancer screening and pregnancy care.
Longitudinal vaginal septum: A wall of tissue runs lengthwise through the vagina, partially or completely dividing it into two channels. It may cause no symptoms or may make tampon use, intercourse, or vaginal delivery more difficult.
Transverse vaginal septum: A band of tissue extends across the vagina and may partially or completely block the vaginal canal. Depending on the degree of obstruction, it can interfere with menstrual flow or cause pelvic pain.
Vaginal agenesis: The vagina may be shortened or incompletely developed. This can occur as part of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, in which the uterus and upper vagina do not fully develop while the ovaries typically function normally.

Some cervical and vaginal differences are discovered during a pelvic exam, while others may not become apparent until someone has difficulty using tampons, begins having intercourse, experiences problems with menstrual flow, or has imaging for another reason.

Treatment is not always necessary. When symptoms are present, treatment depends on the specific anatomy and may range from observation to procedures that remove or reconstruct obstructing tissue.

Hymenal Variants

The hymen is a thin rim of tissue located around the opening of the vagina. There is a wide range of normal hymenal anatomy, but occasionally the tissue develops in a way that partially or completely covers the vaginal opening.

Common hymenal variants include:

Imperforate hymen: The hymenal tissue completely covers the vaginal opening. After periods begin, menstrual blood cannot leave the vagina normally and may collect behind the hymen, causing monthly or worsening pelvic pain, pressure, or difficulty urinating.
Microperforate hymen: There is a very small opening in the hymenal tissue. Menstrual blood can usually pass through, but periods may be prolonged, and inserting or removing tampons may be difficult.
Septate hymen: A band of extra hymenal tissue creates two smaller openings instead of one. This may cause difficulty with tampon use or intercourse.
Cribriform hymen: The hymenal tissue contains several small openings rather than one larger opening. Menstrual blood can pass through, although flow may be slower or prolonged.

Hymenal variants are sometimes discovered during an examination and may not cause any problems. When a variant interferes with menstrual flow, tampon use, or sexual activity, it can usually be treated with a minor procedure to remove the extra tissue and create a normal vaginal opening.

These differences are present from birth and are not caused by sexual activity or tampon use.

Do They Affect Fertility & Pregnancy?

Having a uterine or reproductive tract anomaly does not automatically mean that you will have difficulty becoming pregnant or carrying a healthy pregnancy. Many people with these differences have normal fertility and uncomplicated pregnancies.

The potential impact depends on the specific anatomy and severity of the anomaly. Some uterine anomalies may be associated with an increased risk of:

Miscarriage, particularly with certain abnormalities involving the uterine cavity
Preterm birth
A baby being breech or in another non-head-down position
Fetal growth concerns in some pregnancies
An increased likelihood of cesarean delivery

Some anomalies can also affect fertility or make pregnancy more difficult, while others have little or no effect. Treatment before pregnancy is not necessary for every uterine anomaly and depends on the specific diagnosis, symptoms, and reproductive history.

If you have a known reproductive tract anomaly and are planning a pregnancy, your doctor can help determine whether additional imaging, treatment, or consultation with a specialist would be helpful. During pregnancy, some patients may also benefit from additional monitoring based on their individual anatomy and history.

Reproductive Tract Anomalies & The Urinary System

The reproductive and urinary systems develop alongside one another before birth. Because of this, some people with congenital reproductive tract anomalies may also have differences in the development of the kidneys or urinary tract.

This does not mean that everyone with a reproductive tract anomaly has a kidney abnormality. However, depending on the type of anomaly identified, your doctor may recommend kidney or urinary tract imaging to make sure these structures developed normally.