On occasion, children are born with abnormalities of the kidneys or bladder that require a visit to a pediatric urologist. Many of these abnormalities are noted before the child is born on prenatal ultrasounds. The most common abnormalities of the kidney noted include: an absent kidney, an abnormally positioned kidney, and dilation of the tube that drains urine from the kidney (hydronephrosis or “water on the kidney”). In those children born with only one kidney, often times the other kidney will appear on ultrasound as collection of fluid-filled cysts called a multicystic dysplastic kidney. In the past, many children with these abnormal “cystic” kidneys underwent surgery to remove them. However, by observing these patients over time, we have learned that the vast majority of these kidneys will shrink and disappear with time, not causing any long-term issues. Children with a single functioning kidney also need evaluation by a pediatric urologist as up to 40% of these patients will have a additional abnormality of the urinary tract, with reflux being the most common. Dilation of the tube draining the kidney (hydronephrosis) is a common finding on prenatal ultrasounds, seen in 1-5% of all pregnancies. The vast majority of these children are otherwise healthy. In some cases, the dilation can be due to a partial blockage to the drainage of urine from the kidney or due to reflux. Partial blockages typically occur at the level of the kidney (ureteropelvic junction obstruction) or at the level of the bladder (ureterovesical junction obstruction). While most of these partial blockages will improve with time, it is important that children with dilation of the tube are closely followed to make sure that the dilation does not worsen and require surgery to correct.
Bladder abnormalities also occur. Many of these abnormalities are not noted until after a child completes potty training. In these patients problems are first noted when a child struggles with unwanted leakage of urine (incontinence) or urine infections. In many of these these patients, bladder issues can be corrected without surgery, medication or invasive tests. When evaluating patients with bladder issues, one of the most important areas to assess is bowel function, as bowel issues are seen in a majority of patients with bladder issues, and need to be addressed in order to improve bladder function. In rare circumstances abnormalites of the bladder will be noted before a child is born. More common abnormalities of the bladder noted prenatally are posterior urethral valves (“valves”) and bladder exstrophy. Valves are noted in male babies prior to birth. They are due to an abnormal formation of tissue in the urethra. The tissue causes the bladder to be unable to empty effectively. As a result, these boys will require surgery in the newborn period to remove the tissue. In addition, these patients require long-term follow-up with a pediatric urologist to assure that the bladder functions properly after the obstruction has been relieved and to monitor kidney function. Bladder exstrophy is a rare, but complex condition in which a child is born with the bladder on the outside of the abdomen. These patients require complex surgery to correct their bladder issues as well as close follow-up by a pediatric urologist.