If urotropin is applied clinically to promote ovulation, ultrasound monitoring of follicle growth is required after the injection under normal circumstances. The number of follicles grows at a rate of 1.5-2mm per day and ultrasound monitoring is recommended. If the follicles are dominant, e.g. 18mm in diameter, intramuscular injection of chorionic gonadotropin is recommended to induce the follicles to rupture and expel the eggs. The chorionic gonadotropin injection can be given 24 hours with the option of intercourse, and the chances of pregnancy will be increased. It is important to pay attention during the application of urinary gonadotropin to promote ovulation. If there is pain in the lower abdomen or little urination, it is likely that there is follicular hyperstimulation and should be taken seriously. If this occurs, it is important to give prompt treatment.