Bladder exstrophy (EK-stroh-fee) is a rare birth defect in which the bladder develops outside the fetus. The exposed bladder can't store urine or function normally, resulting in urine leakage (incontinence).

Problems caused by bladder exstrophy vary in severity. They can include defects in the bladder, genitals and pelvic bones, as well as defects in the intestines and reproductive organs.

Bladder exstrophy may be spotted on a routine ultrasound during pregnancy. Sometimes, though, the defect isn't visible until the baby is born. Babies born with bladder exstrophy will need surgery to correct the defects.


Bladder exstrophy is the most common in the larger group of birth defects called the bladder exstrophy-epispadias complex (BEEC). Children with BEEC have one of the following:

  • Epispadias. This is the least severe form of BEEC, in which the tube to expel urine (urethra) doesn't fully develop.
  • Bladder exstrophy. This defect causes the bladder to form on the outside of the body. The bladder is also turned inside out. Usually, bladder exstrophy will involve organs of the urinary tract, as well as the digestive and reproductive systems. Defects of the abdominal wall, bladder, genitals, pelvic bones, final section of the large intestine (rectum) and opening at the end of the rectum (anus) can occur.

    Children with bladder exstrophy also have vesicoureteral reflux. This condition causes urine to flow the wrong way — from the bladder back up into the tubes that connect to the kidneys (ureters). Children with bladder exstrophy also have epispadias.

  • Cloacal exstrophy. Cloacal exstrophy (kloe-A-kul EK-stroh-fee) is the most serious form of BEEC. In this condition, the rectum, bladder and genitals don't fully separate as the fetus develops. These organs may not be correctly formed, and the pelvic bones are affected as well.

    The kidneys, backbone and spinal cord also may be affected. Most children with cloacal exstrophy have spinal abnormalities, including spina bifida. Children born with protruding abdominal organs probably also have cloacal exstrophy or bladder exstrophy.


The cause of bladder exstrophy is unknown. Researchers think that a combination of genetic and environmental factors likely plays a role.

What is known is that as the fetus grows, a structure called the cloaca (klo-A-kuh) — where reproductive, urinary and digestive openings all come together — doesn't develop properly in babies who develop bladder exstrophy. Defects in the cloaca can vary a lot depending on the age of the fetus when the developmental error occurs.

Risk factors

Factors that increase the risk of bladder exstrophy include:

  • Family history. Firstborn children, children of a parent with bladder exstrophy or siblings of a child with bladder exstrophy have an increased chance of being born with the condition.
  • Race. Bladder exstrophy is more common in whites than in other races.
  • Sex. More boys than girls are born with bladder exstrophy.
  • Use of assisted reproduction. Children born through assisted reproductive technology, such as IVF, have a higher risk of bladder exstrophy.


Without surgery

Without treatment, children with bladder exstrophy won't be able to hold urine (urinary incontinence). They're also at risk of sexual dysfunction and have an increased risk of bladder cancer.

After surgery

Surgery can reduce complications. The success of surgery depends on how severe the defect is. Many children who have surgical repair are able to hold urine. Young children with bladder exstrophy may walk with their legs turned somewhat outward due to the separation of their pelvic bones.

Long-term complications

People born with bladder exstrophy can go on to have normal sexual function, including the ability to have children. However, pregnancy will be high risk for both mother and baby, and a planned cesarean birth may be needed.

Bladder exstrophy care at Mayo Clinic

Feb. 11, 2022
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