A disease characterized by three major findings (triad): deficient abdominal muscles (causing the skin of the abdomen to wrinkle like a prune), undescended testicles , and a dilated abnormal urinary tract.
Causes, incidence, and risk factors
The underlying causes of prune belly syndrome are unknown. There is blockage to the flow of urine from the kidney to the outside of the body during fetal life. For example, dilatation of the urinary tract may develop as a result of urethral obstruction in the womb. The incidence is approximately 1 in 30,000 to 40,000 births. Boys are almost solely affected. Expectant mothers carrying affected infants may develop varying degrees of oligohydramnios (insufficient amniotic fluid ) that predisposes the infant to lung problems (see Potter syndrome ). The newborn infant has a wrinkled abdomen (it looks like a prune). This appearance results from swelling with fluid in the womb then loss of that fluid after birth leading to wrinkles of excess skin. The appearance is accentuated by the lack of adequate abdominal musculature. Genital abnormalities may be prominent as undescended testes . Approximately one third of the infants are either stillborn or die within the first few weeks of life from severe lung, kidney, or combined problems. Other abnormalities may be present including musculoskeletal defects, heart abnormalities, and a rotated bowel.
Signs and tests
Renal system defects that appear on physical examination or tests include:
dilated renal collecting structures megaureter (enlarged ureter) dilated bladder megalourethra (abnormally enlarged urethra) cryptorchidism ( undescended testicle ) Other findings may include:
prune belly appearance hypoplastic lungs (underdeveloped lungs, typical of Potter syndrome ) Tests:
fetal ultrasound that demonstrates urinary tract defects ultrasound showing enlarged kidney, ureter or bladder X-ray of the kidneyIVP , intravenous pyelogram
X-ray of the chest
Treatment
Treatment requires surgical intervention to maintain drainage of the renal system and protect remaining renal function. Typical surgeries might include:
pyelostomy (an opening into the kidney; usually with placement of a drainage tube) vesicostomy (an opening into the bladder; usually with placement of a drainage tube) reconstructive surgery prenatal surgery to correct posterior urethral valves that don't open is likely to become more widely available in the future Other treatment:
preventive antibiotics to avoid a urinary tract infection
antibiotics for acute infection
orchidopexy (testicle repair) for undescended testes
Expectations (prognosis)
The outlook is poor to fair. About one third of affected infants die early or are still born. Infants that survive may have life-long urinary tract or other problems.
Calling your health care provider
This diagnosis used to only be made in the hospital at the time of birth. If you have a child with diagnosed prune belly syndrome, call your health care provider at the first sign of a urinary tract infection or other urinary symptoms. If your child is diagnosed with distended bladder or enlarged kidneys on prenatal ultrasound seek prompt consultation with a specialist in high-risk obstetrics or a perinatologist.
Prevention
There is no known guaranteed prevention. If prenatal diagnosis of urinary tract obstruction is made some it may be possible to prevent it progressing to prune belly syndrome with prenatal surgery as noted in Treatment above.