Cloacal Deformities

What is a cloacal deformity?

A cloacal deformity is a rare type of anorectal malformation that occurs while a female fetus is still developing in its mother's womb. The rectum, vagina and urinary tract are supposed to separate creating three openings at the surface of the skin. In a cloacal deformity, the rectum, vagina and urologic structures join into one common channel. Cloacal malformations are rare and occur in about 1 in 20,000 to 1 in 25,000 newborn females.

Cloaca Malformation

What are the signs of a cloacal deformity?

There are many variations of cloacal deformities, but all of them involve a single opening in the skin where the urethra would normally open. This usually leads to a common channel where the urethra and bladder, genital tract and the rectum join. Normally, each of these channels has a separate opening at the skin’s surface, but in a cloacal deformity, the three tracts merge into one common channel and one opening.

Cloacal deformities can vary depending on where these three tracts merge. If they join at a low point, the baby lacks a visible anus but has a short common channel, which allows waste to leave the body freely.

If the three tracts come together at a high point, the common channel is long, which makes it more difficult for waste to leave the body.

Specific defects may include:

  • variation in the degree of development of the bladder, reproductive organs, abdominal wall and rectum
  • vaginal duplication or atresia (absence or abnormal closure of the vagina)
  • lack of or failure in the development of other female reproductive structures such as the uterus and fallopian tubes
  • imperforate anus, a condition where the anus has not been formed or is perforated and the colon connects to the bladder

Cloacal deformities are often associated with the following conditions:

  • anomalies of the upper urinary system, sometimes including anomalies in one or both kidneys
  • anomalies of the bones in the pelvis or lower spine
  • anomalies of the spinal cord and, sometimes, the affected nerves

What is a cloacal exstrophy?

The most complicated cloacal deformity is cloacal exstrophy, a severe birth defect in which a child is born with many intra-abdominal structures, such as the large intestine and bladder, exposed. An omphalocele (a birth defect in which abdominal organs stick out of the navel) is often present as well.

What causes cloacal deformities?

The cause of cloacal deformities is unknown. It doesn’t appear that any medications or activities of the expectant parents have any impact on the development of cloacal deformities. Based on our current knowledge, it is very unlikely that this condition can be prevented.

How we care for a cloacal deformity

Cloacal deformities require surgical repair. The clinicians in the Colorectal and Pelvic Malformation Center at Boston Children’s Hospital have extensive experience in repairing a wide range of cloacal deformities. We work together as a team to provide you and your child with a coordinated plan for reconstruction and future follow-up care — and can start planning interventions even before your child is even born.