Müllerian anomalies at a glance

• Müllerian anomalies are congenital abnormalities of the reproductive organs for a person who has a period.
• Abnormal development of the reproductive tract may involve the uterus, fallopian tubes, cervix and/or vagina.
• Many people with Müllerian anomalies are asymptomatic.
• Some müllerian anomalies can cause pelvic pain, pain with intercourse, difficulty using tampons or pre-term births; surgical treatment may help with these issues.

What are Müllerian anomalies?

Müllerian anomalies are congenital abnormalities of the reproductive tract that result in atypical development of the uterus, fallopian tubes, cervix and/or vagina. Although this may cause no problems or symptoms, Müllerian anomalies are also causes of infertility, pelvic pain and other issues.

Every embryo contains ducts or tubes that grow into internal reproductive organs during prenatal development. Named after the German physiologist who studied them, the Müllerian ducts are two tube-like structures that develop and fuse into the reproductive system, specifically the fallopian tubes, uterus, cervix and upper two-thirds of the vagina. Malformations of the internal reproductive organs or Müllerian anomalies occur when these ducts develop or fuse abnormally.

These anomalies are classified as either obstructive or nonobstructive. Obstructive anomalies block blood flow from the uterus through the vagina during menstruation and usually present during adolescence. Patients with nonobstructive Müllerian abnormalities have atypical development of the reproductive tract without menstrual obstruction or pain.

We offer treatments for most Müllerian anomalies.

Obstructive Müllerian anomalies

An obstructive Müllerian anomaly causes the blockage of blood flow during the menstrual cycle, which may result in severe pelvic pain. The blockage prevents blood from flowing into the vagina from the uterus because either the uterus or vagina is not properly connected or a dividing wall of tissue (known as a vaginal septum) obstructs the outflow of menstrual blood.

These anomalies are typically diagnosed during adolescence. Patients may present with absent menstruation, worsening pelvic pain or an abdominal mass. Following are the main types of obstructive Müllerian anomalies.

Transverse vaginal septum

This condition indicates that the vagina is shortened and blocked by a wall of tissue that formed during development of the genital tract. When the tissue forms across the vagina in this way, it will block or partially block menstrual blood flow, usually resulting in worsening cyclic pelvic pain.

Distal vaginal agenesis

This is a rare condition in which the lower part of the vagina does not develop. Symptoms and signs typically go unnoticed until puberty. Similar to a transverse vaginal septum, menstrual blood flow is blocked, usually resulting in worsening cyclic pelvic pain.

Cervical agenesis

Cervical agenesis happens when a baby is born without a cervix, the opening in the uterus that connects to the vagina. Typically, this disorder occurs in conjunction with vaginal agenesis. Symptoms include abdominal pain and lack of menstruation during puberty.

Obstructed hemivagina

Obstructed hemivagina and ipsilateral renal anomaly (OHVIRA) is a complex syndrome. This rare congenital abnormality of the urogenital tract occurs when a person is born with two cervixes and two uteruses. Additionally, there is a vaginal septum that blocks outflow of menstrual blood from one of the uteri. People with OHVIRA usually also have an underdeveloped or missing kidney. Typical symptoms are pelvic masses and pain in the abdomen, vagina or pelvis.

Nonobstructive abnormalities

Nonobstructive Müllerian anomalies do not involve menstrual blockage, rather they are variations in uterine and/or vaginal anatomy.

Nonobstructive anomalies involving the vagina may present with absent menstruation, painful intercourse or difficulty using tampons. Nonobstructive anomalies involving the uterus are typically asymptomatic. Below are the types of nonobstructive anomalies.

Longitudinal vaginal septum

This condition arises when the lower parts of the two Müllerian ducts do not merge together properly during fetal development. The result is a wall of tissue running down the length of the vagina separating it into two canals.

A longitudinal septum can cause tampon leakage during periods, because the tampon is only inserted into one canal. It may also cause pain during intercourse. Some people with a longitudinal septum have no symptoms at all.

Müllerian agenesis (Mayer-Rokitansky-Küster-Hauser syndrome)

Müllerian agenesis is absence of a uterus and upper vagina and is also known as Mayer-Rokitansky-Küster-Hauser syndrome. A person born without a uterus or a very small uterus (also known as a uterine remnant) cannot carry their own pregnancies. However, since ovaries are normal, assisted reproduction options including in vitro fertilization (IVF) and gestational carriers are available. Vaginal creation or lengthening can be considered when desired by the patient.

Bicornuate uterus

The most common form of Müllerian anomaly is the bicornuate uterus, which results from incomplete fusion of the Müllerian ducts during fetal development. This means the uterus develops into a shape like two connected horns with a deep indentation between them. This anomaly might create a small uterine cavity, which may result in early delivery, malpresentation or growth restriction during pregnancy.

Double uterus (uterus didelphys)

A didelphys uterus forms when the Müllerian ducts do not fuse during fetal development. In this condition there are two uteri and two cervices. In about 70% of cases, the vagina is also duplicated (longitudinal vaginal septum). Because each uterus is smaller than a typically formed uterus, pregnancy can be complicated by early delivery, malpresentation or growth restriction.

Unicornuate uterus

Unicornuate uterus is a rare Müllerian anomaly, which occurs when one duct either fails to develop or under develops. The result is a banana-shaped half-uterus, frequently coinciding with a missing kidney or other kidney issues.

Septate uterus

A septate uterus is when the uterine cavity is divided by a septum (wall). The septum may be complete to the cervix or only divide part of the uterus. This anomaly increases a woman’s risk of miscarriage, early delivery, malpresentation or growth restriction during pregnancy.

Diagnosing Müllerian anomalies

Providers use imaging technology to diagnose or confirm Müllerian anomalies. These techniques include pelvic ultrasonography, magnetic resonance imaging (MRI) and hysterosalpingogram (HSG).

Treatment options

Obstructive anomalies, especially those that cause severe pelvic pain, may need urgent attention and surgical intervention. These cases can be complex and patients should be evaluated by an experienced provider.

For Müllerian agenesis, vaginal elongation by dilation is a safe, nonsurgical option and is successful in up to 95% of people. Surgical creation of a vagina requires general anesthesia and is usually maintained with vaginal dilation in the post-operative period.

There are several methods to surgically create a vagina, but most require taking tissue or skin from another part of your body.

Longitudinal vaginal septa are resected vaginally and, if indicated, uterine septa are removed with an outpatient hysteroscopic surgery. During this procedure, scissors are used to cut the septum through a tiny scope in the vagina or uterus. Ultrasound or laparoscopy may also be used during surgery to assist with particularly difficult cases.

While many people with uterine abnormalities do not need treatment, it is recommended that anyone suffering from multiple miscarriages, painful or no periods, difficulty using a tampon, or pain during sex seek diagnostic help from a gynecologist.

The Pediatric Adolescent Gynecology team at Children’s Hospital Colorado has expertise with Müllerian anomalies. The team is available by self-referral or referral from your physician to help take care of you and your reproductive health needs.