What is neonatal hydronephrosis?
Neonatal (neo-NA-tal) hydronephrosis (hi-dro-ne-FRO-sis) is a condition affecting the kidneys in newborns. This occurs when the baby’s urine does not drain properly into the bladder. When this happens, the urine gets trapped and overfills the kidneys. The collecting part of the kidneys begins to stretch and enlarge (get bigger). This then leads to pain, bleeding, or frequent infections, which may further damage your baby’s kidneys. Mild neonatal hydronephrosis may resolve before your baby reaches the age of one year. The urinary system is made up of the kidneys, ureters, bladder, and urethra. The kidneys are two bean-shaped organs and are in the back of the abdomen (belly) on both sides of the spine. These filter the blood to remove waste products and form urine. The urine flows from the kidneys down through the tubes called ureters. From the ureters, the urine goes down and is stored for a short time in the bladder. The urine passes out of the body through another tube, called the ure
