Fetuses with enlarged kidneys are born healthy, which are seen in physiological causes of enlarged kidneys, and pathological causes of enlarged kidneys are usually problematic. If the fetus is holding back urine during the ultrasound examination, there will be enlargement of both kidneys through the examination, and the enlargement of both kidneys will be improved if the ultrasound examination is done again after a period of time. The fetus born with enlarged kidneys due to physiologic reasons is usually healthy. Fetuses with enlarged kidneys by ultrasound examination are caused by pathologic reasons, which may be hydronephrosis, polycystic kidneys, congenital developmental abnormality of kidneys caused by chromosomal abnormality of the fetus, and they are not necessarily healthy after birth. If the fetus has enlarged kidneys after pregnancy, amniocentesis will be performed to determine whether there is any chromosomal abnormality, and then consider whether to continue the pregnancy.