What Is Mullerian Anomalies?
Mullerian anomalies affect up to four percent of females. The anomaly is considered a ‘congenital disorder’, meaning it occurs during fetal development and is present at birth. As an embryo forms, two paired mullerian ducts develop into the female reproductive tract which includes the fallopian tubes, uterus, cervix, and upper two thirds of the vagina. A wide variety of malformations can occur when this system is disrupted.
There is not one cause of müllerian anomalies. Some may be hereditary, others may be attributed to a random gene mutation or developmental defect.
What Types of Müllerian Anomalies Exist?
There are several different forms of mullerian anomalies ranging from the absence of a uterus to the formation of a half uterus or a double uterus to a uterus divided by a septum. All types affect the reproductive tract in varying degrees. They include:
Agenesis & hypoplasia: Mayer-Rokitansky-Kuster-Hauser syndrome is most common. All or part of the müllerian tract fails to form, or is extremely underdeveloped.Unicornuate uterus (UU): When one müllerian duct is underdeveloped or fails to develop, a banana-shaped half-uterus is formed. A missing kidney or other kidney problems accompany this asymmetric anomaly more than they do other müllerian anomalies. This is a rare condition. Uterus didelphys (UD): Commonly referred to as a ‘double uterus’. There may be complete duplication of the vagina, cervix and uterus, and the two halves may be divided by a ligament of connective tissue. UD is has the best pregnancy outcomes of all the MAs. Bicornuate uterus (BU): This is the most common form of müllerian nomaly. Described as a womb with two horns. The womb is not pear-shaped, instead it is shaped like a heart, with a deep indentation at the top. This means that the baby has less space to grow than in a normally shaped womb.
Septate uterus: Occurs when the inside of the uterus is divided by a wall or the septum. The septum may extend only part way into the uterus or it may reach as far as the cervix.
DES-related uterus: A T-shaped uterine cavity, dilated horns and malformed cervix and upper vagina may characterize this anomaly. A T-shaped uterus is sometimes caused by maternal ingestion of DES, although sometimes the cause is unknown.
Arcuate uterus (AU): The fundus of the uterus may be indented slightly both inside and outside. The shape is so slight that it is considered a variation of normal.
How is the Condition Diagnosed?
Müllerian anomalies are often recognized at the onset of puberty — when an adolescent begins to menstruate or when a young female fails to get her menstrual period. The condition may also be diagnosed when a woman has trouble conceiving, or maintaining a pregnancy. Some anomalies are associated with abdominal or pelvic pain, discomfort during sex, or menstrual abnormalities.
Imaging technology can diagnose a müllerian anomaly and may also detect other existing reproductive conditions. Diagnostic testing may include:
pelvic ultrasound three dimensional ultrasound magnetic resonance imaging (MRI) hysterosalpingogram (HSG) laparoscopy hysteroscopyA combination of tests may be recommended to establish the most accurate diagnosis.
How are Mullerian anomalies treated?
In many cases, the condition can be left untreated, in particular when it does not significantly affect reproduction. Müllerian anomalies that prevent menstruation or cause significant pain are usually surgically treated. Surgical intervention depends on the extent of the individual problem.
Can a female with this condition eventually become pregnant and carry to term?
Mullerian anomalies that affect fertility such as a septated uterus (a partitioned uterus) can be corrected, thus improving chances of having a successful pregnancy. Women with a congenital reproductive anomaly who have not been able to achieve pregnancy within six months of trying should see a fertility specialist skilled in reproductive surgery. Surgery can repair the defect, eliminate discomfort during menses or sexual relations and improve fertility and pregnancy outcomes.