Infants with single kidneys may be due to congenital isolated kidneys, caused by the inheritance of chromosomal abnormalities and associated with environmental factors. Single-kidney deletion can also occur in a subset of syndromes and their accompanying malformations due to chromosomal abnormalities. The causative genes and environmental factors that lead to single-kidney agenesis during renal development are increasingly being recognized. Environmental factors, mainly maternal diseases, intrauterine fetal growth retardation, early pregnancy administration of hormones, aminoglycoside antibiotics (e.g., gentamicin), nonsteroidal anti-inflammatory drugs (e.g., indomethacin), immunosuppressants (e.g., azathioprine), angiotensin receptor inhibitors, uric acid-lowering medications (colchicine, allopurinol), and chemotherapeutic agents have been associated with the development of single-kidney agenesis. Single kidney infants may also have other causes, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.