The exact causes of prune belly syndrome are unknown. The condition affects mostly boys.
While in the womb, the developing baby's abdomen swells with fluid. Often, the cause is a problem in the urinary tract. The fluid disappears after birth, leading to a wrinkled abdomen that looks like a prune. This appearance is more noticeable due to the lack of abdominal muscles.
Prune belly syndrome is a group of rare birth defects that involves these three main problems:
- Poor development of the abdominal muscles, causing the skin of the belly area to wrinkle like a prune
- Undescended testicles
- Urinary tract problems
Exams and Tests
A woman who is pregnant with a baby who has prune belly syndrome may not have enough amniotic fluid (the fluid that surrounds the fetus). This can cause the infant to have lung problems from being compressed in the womb.
An ultrasound done during pregnancy may show that the baby has a swollen bladder or enlarged kidney.
In some cases, a pregnancy ultrasound may also help determine if the baby has:
- Heart problems
- Abnormal bones or muscles
- Stomach and intestinal problems
- Underdeveloped lungs
The following tests may be performed on the baby after birth to diagnose the condition:
Prune belly syndrome is a serious and often life-threatening problem.
Many infants with this condition are either stillborn or die within the first few weeks of life. The cause of death is from severe lung or kidney problems, or from a combination of birth problems.
Some newborns survive and can develop normally. Others continue to have many medical and developmental problems.
Complications depend on the related problems. The most common are:
- Bone deformities (clubfoot, dislocated hip, missing limb, finger, or toe, funnel chest)
- Disease of the urinary tract (may need dialysis and a kidney transplant)
Undescended testicles can lead to infertility or cancer.
There is no known way to prevent this condition. If the baby is diagnosed with a urinary tract obstruction before birth, in rare cases, surgery during the pregnancy may help prevent the problem from progressing to prune belly syndrome.
The following resources can provide more information on prune belly syndrome:
- Prune Belly Syndrome Network -- www.prunebelly.org
- National Organization for Rare Disorders -- rarediseases.org/rare-diseases/prune-belly-syndrome
Weak abdominal muscles can cause:
- Delay in sitting and walking
- Difficulties coughing
Urinary tract problems can cause difficulty urinating.
Early surgery is recommended to fix weak abdominal muscles, urinary tract problems, and undescended testicles.
The baby may be given antibiotics to treat or help prevent urinary tract infections.
When to Contact a Medical Professional
Prune belly syndrome is usually diagnosed before birth or when the baby is born.
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 a pregnancy ultrasound shows that your baby has a swollen bladder or enlarged kidneys, talk to a specialist in high-risk pregnancy or perinatology.
Caldamone AA, Denes FT. Prune-belly syndrome. In: Wein AJ, Kavoussi LR, Partin AW, Peters CA, eds. Campbell-Walsh Urology. 11th ed. Philadelphia, PA: Elsevier; 2016:chap 140.
Elder JS. Obstruction of the urinary tract. In: Kliegman RM, Stanton BF, St. Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics. 20th ed. Philadelphia, PA: Elsevier; 2016:chap 540.
Merguerian PA, Rowe CK. Developmental abnormalities of the genitourinary system. In: Gleason CA, Juul SE, eds. Avery's Diseases of the Newborn. 10th ed. Philadelphia, PA: Elsevier; 2018:chap 88.