“I just had an ultrasound and found out that my baby has a kidney abnormality. What does that mean? What are my next steps?”
Kidney abnormalities are found relatively often on ultrasound during pregnancy. The good news is that most of the time your baby will not have a life or health-threatening condition. There are some rare serious findings that require immediate referral to a urologist while you are still pregnant, but most of the time what is seen is hydronephrosis (enlargement) of only one kidney. In that case, your doctor can safely choose to wait until you deliver to involve a urologist.
The next step for most babies is to have two tests done 2-3 days after delivery. First, an ultrasound is repeated to confirm that there really is a kidney abnormality. If there is, then usually a second test is done where a tiny, soft catheter is placed through the urethra into the bladder. A fluid that lights up on X-ray is gently dripped into the bladder while pictures are taken of the bladder and kidneys. These two tests will usually show what kind of abnormality the kidney might have.
The most common diagnosis is something called “reflux,” where urine “runs backward” from the bladder to one or both kidneys, causing them to appear enlarged. The next most common finding is the partial blockage of a kidney. In either case, your urologist will usually prescribe a small daily dose of an antibiotic to prevent infections and will periodically repeat the same two tests over the coming years. Either condition will have a good chance of resolving on its own. Further specialized tests may be needed later, and some conditions may even require surgery. Even if that happens, though, your baby will likely do very well and live a normal healthy life.
Bradley Anderson, M.D. is board-certified in adult and pediatric urology and is a Fellow of the American College of Surgeons. He practices at St. Vincent Healthcare and writes a regular column on urologic issues for Pediatrics for Parents.