The literature review presents an analysis of the current state of the existing system for monitoring congenital malformations in children and fetuses. The birth rate of children with developmental defects in different countries and on the territory of the Russian Federation varies over a wide range, both over time and across observation areas. Using the example of defects and anomalies of the urinary system organs, the issues of defining the terms “congenital defect” and «developmental anomaly» are discussed. The problem remains that researchers have used various classifications over the years to systematize birth defects. To ensure a unified approach to the registration of developmental defects, it is advisable to take into account all their forms according to the International Classification of Diseases, separating defects from congenital anomalies, and also to single out defects from the entire spectrum for mandatory recording, which is important for comparing regional indicators with the results of individual researchers and with the data of the International register. A prerequisite for organizing the work of registers is the existence of uniform definitions, classifications, and coding of registered congenital malformations.