A newborn’s failure to urinate for 12 hours may be caused by very low water intake, loss of large amounts of body fluids from other sources, and renal failure. 1. Very low water intake: In the case of a newborn who drinks very little water or even no water, it can lead to the newborn’s failure to urinate for 12 hours. 2. Loss of large amount of body fluids from other channels: If the newborn has severe vomiting, diarrhea, etc., which leads to the loss of large amount of body fluids from other channels, the newborn may not urinate for 12 hours. Usually, the anuria can be improved after treatment of the above conditions. 3. Renal failure: in the presence of acute nephrotic syndrome, renal failure and other renal diseases, will affect the urinary excretion, resulting in newborns 12 hours without urine. Newborns 12 hours without urine may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to determine the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.