Prune belly syndrome, also known as Eagle-Barrett syndrome, refers to a group of birth defects that cause external and internal abnormalities. The most common of these are:
• Poorly developed abdominal muscles that make the stomach appear wrinkled, much like the skin of a prune
• Urinary tract abnormalities, including an enlarged bladder
Additional conditions associated with the syndrome include underdeveloped lungs, chronic renal failure, scoliosis, congenital hip dislocations, and heart defects.
Causes of Prune Belly Syndrome
Prune belly syndrome affects one in 40,000 babies, 97 percent of which are boys. Researchers don't know the exact cause, but because it appears to be sex-linked and have a heritable component they believe genetics plays a role (although they have yet to pinpoint any causative genes).
Prune belly syndrome develops in utero, possibly when a blockage prevents the fetal bladder from draining properly. As a result, the fetus' bladder begins to swell with fluid and protrude into its abdominal cavity.
Symptoms Associated with Prune Belly Syndrome
Prune belly syndrome has a variety of symptoms, and those symptoms can vary in severity. The most common visible symptom is a wrinkled abdomen. This is a sign of poorly developed abdominal muscles, which affect a baby’s ability to sit up properly. Boys often have undescended testes, in which their testicles are located in the abdomen rather than the scrotum, while others may be born without any testicles at all.
There are numerous other ways in which the urinary tract is affected, including:
- Widening of the ureters (tube that transports urine from each kidney to the bladder)
- Hydroureter (collection of urine in the ureters)
- Enlarged or twisted ureters
- Hydronephrosis (accumulation of urine in the kidneys)
- Vesicoureteral reflux (when urine backflows from the bladder into the ureters)
- Enlarged bladder
Children with prune belly syndrome often experience urinary tract infections (UTIs) when urine backs up from the bladder, a condition that allows bacteria to multiply and spread.
Diagnosing Prune Belly Syndrome
Since prune belly syndrome occurs during development, a physician may detect the condition during routine prenatal ultrasounds. If nothing is seen on ultrasound, physical signs present at birth (visible wrinkling of the abdomen or undescended testes) may be enough to make a diagnosis.
If a pediatrician suspects prune belly syndrome, she may recommend a number of diagnostic tests to confirm. These include:
- Blood tests to determine how well the kidneys are filtering waste products
- MRI to image the urinary tract
- Renal bladder ultrasound (RBUS) to image the bladder and kidneys
- Voiding cystourethrogram (VCUG) to determine how well a bladder is emptying
Treatment for Prune Belly Syndrome
Prune belly syndrome treatment depend upon the condition's severity and whether there are any associated abnormalities. Many children are placed on low-dose prophylactic antibiotics to prevent urinary tract infections. If less conservative measures fail, surgery can be used to open the bladder for urine drainage, restructure the abdominal wall and urinary tract, or move the testes into position.
Caldamone A, Woodard J. (2007). Prune belly syndrome. In: Wein AJ, ed. Campbell-Walsh Urology. 9th ed. Philadelphia, Pa: Saunders Elsevier; chap 118.