Antenatal Urologic Conditions

Doctors sometimes detect fetal abnormalities when women have routine sonograms during pregnancy, and many of these abnormalities are in the baby's developing kidneys, ureters, or bladder. The Columbia University Irving Medical Center Division of Pediatric Urology is an integral part of the Maternal/Fetal Medicine Center and the Center for Prenatal Pediatrics at NewYork-Presbyterian/Morgan Stanley Children's Hospital. Our staff works closely with other specialists in obstetrics, neonatology, pediatric anesthesiology, and surgeons in all pediatric sub-specialties. These collaborations are invaluable for detecting any urologic problem during pregnancy and ensure a seamless transition from pregnancy to delivery to treatment of the infant after birth.


Sometimes called "large kidneys" or "swollen kidneys," hydronephrosis is a term for extra fluid in the kidneys or ureters and it is a symptom of many of the other conditions listed here. When hydronephrosis is found during pregnancy, it usually resolves during the first few years of the child's life. It is critical that an experienced pediatric urologist determine the cause of the condition and whether it a serious problem.

Ureteropelvic Junction (UPJ) Obstruction

UPJ obstruction is a blockage that develops where the ureter and kidney meet—at the ureteropelvic junction. UPJ obstruction is usually caused by poor peristalsis, the rhythmic propulsion of urine toward the bladder. In UPJ obstructions, urine often backs up in the kidney because a section of the ureter is not muscular enough to push the urine forward. Obstructions can also develop if the ureter is very narrow, kinked, or compressed by a blood vessel. Surgeons can remove the lazy or narrowed section of the ureter to reestablish normal flow.

Vesicoureteral Reflux (VUR)

VUR is the backward flow of urine from the bladder into the ureter and kidney. Most low-level reflux resolves itself during the first few years of a child's life. Doctors often treat children with VUR with antibiotics to prevent urinary tract infections (UTIs), because a child with a UTI and reflux can go on to develop a kidney infection (pyelonephritis) and sometimes kidney damage. In some cases, reflux requires surgical treatment.

Ureterovesical Junction Obstruction (UVJ)

UVJ obstruction is a blockage at the point where the ureter enters the bladder. UVJ obstructions usually develop because a section of the ureter near the bladder is not muscular enough to push the urine forward. Surgeons may remove the obstructed segment and taper or narrow the ureter so that it fits properly into the bladder.


Ureterocele is a cyst-like enlargement of the ureter in the bladder. It is typically found in children who develop two ureters instead of one draining the kidney. Treatment of the ureterocele depends on the size of the constriction and how well the kidney is functioning. Surgeons may remove large ureteroceles that cause a great deal of reflux (or back-flow) into the ureter.

Ectopic Ureter

Ectopic ureter is a condition in which one or both ureters drain somewhere other than the bladder. Like ureteroceles, ectopic ureters usually develop in children with two instead of one ureter; these can be quite dilated. In girls, ectopic ureters can cause continuous incontinence. Doctors can usually correct this problem through surgery.

Posterior Urethral Valves (PUV)

PUV are abnormal leaflets (valves) in the male urethra that can partially or completely block the flow of urine out of the bladder. PUV can cause mild to severe hydronephrosis in one or both kidneys, but in many cases both kidneys function reasonably well. Children with PUV should be delivered and cared for in a medical center with doctors from all of the pediatric specialties (anesthesia, neonatology/ICU, pediatric urology, pediatric nephrology). If the child has reflux, poor kidney function, and/or poor bladder function, he may need future procedures to correct the problem.

Prune Belly Syndrome (PBS)

PBS is a rare condition in which a male child has insufficient abdominal wall muscles and a wrinkled abdominal wall, testes in the abdomen, and abnormalities of the urinary tract. Many other abnormalities are associated with PBS, so it is critical that the child is delivered in a major pediatric center that has specialists in anesthesia, neonatology/ICU, pediatric urology, pediatric nephrology, cardiology, and pulmonology. Treatment generally includes surgery to bring the testes into the scrotum, correct the ureteral reflux, and reconstruct the abdominal wall.

Multicystic Dysplastic Kidney (MCDK)

MCDK is a kidney that has been replaced by non-functioning cysts. In children with MCDK, the other kidney usually functions well and the child is able to lead a perfectly normal life. Studies have shown that many MCDKs eventually shrink, and it is rarely necessary to remove the MCDK in the newborn period.