Has anyone else ever had your OB tell you something was wrong with your baby's kidneys? When he was doing my ultrasound…

Has anyone else ever had your OB tell you something was wrong with your baby's kidneys? When he was doing my ultrasound he seen something on his kidneys and I can't remember what word it was that he used. It was a big word lol. But I really want to know what it is so I can find info on it. He's having me see a specialist also. But he said it was common on baby boys. Anybody know what it might be?