Mullerian Duct

Definition - What does Mullerian Duct mean?

The Mullerian ducts are paired ducts which coexist in a developing fetus, from which the female internal reproductive organs are derived by a lateral fusion of the two ducts. These ducts conjoin and form the uterus, the cervix, the fallopian tubes and upper end of the vagina. Complete fusion results in a single uterine cavity. If the baby is a boy, these ducts disappear by the third month of fetal life.

Congenital (from birth) uterine anomalies can arise from a defect in the fusion of the mullerian ducts, and can be the cause for infertility or miscarriages, preterm births and difficult childbirth.

FertilitySmarts explains Mullerian Duct

Development of the mullerian ducts begins at about the fourth week of life. During normal development, these ducts come together side by side and there is a fusing of some length of the two ducts. This leads to the formation of a single uterus with an open cavity and two fallopian tubes. However, in certain cases the uterus and fallopian tubes may not form normally. These malformations are called mullerian duct anomalies (MDA) or defects. The range of these defects is wide, and though on one end of the spectrum the defects may go unnoticed, at the other end mullerian anomalies may make it difficult or impossible to become pregnant. Common types of fusion disorders include:

  • A complete duplication (uterine didelphys) with two uteri, cervices and vaginas.
  • A bicornuate uterus, in which two uteri share a single cervix and vagina.
  • A septate uterus in which there is a fibrous band of tissue going through the uterus. This can be removed hysteroscopically (telescopic instrument passed through the cervix).
  • An arcuate uterus, in which there is a “dent” on the top of the uterus.

Women with fusion disorders are more likely to have miscarriages and preterm births. Even if the pregnancy goes to full term, the position of the baby at birth may not be correct, making it difficult for a normal passage of the baby through the birth canal. The nature of the difficulty depends on the kind and extent of the fusion disorder. Often kidney problems develop in women with mullerian abnormalities, mainly because the kidneys develop next to the mullerian system.

The ways to diagnose a fusion disorder is through ultrasound, magnetic resonance imaging (MRI) or a surgical procedure.

The most common mullerian duct anomalies seen in the fertility clinic include an arcuate uterus and a T-shaped uterus.

Share this: