Ovulation stimulation can be started after the down-regulation when all the indicators reach the standard, that is, 2~4 weeks after the down-regulation. Before IVF, the pituitary gland is down-regulated by medication to inhibit spontaneous ovulation, thus promoting more follicles to develop and mature at the same time. Under normal circumstances, you can start ovulation stimulation about 2 to 4 weeks after the down regulation, for the ultra-long program down regulation is recommended to start ovulation stimulation after 4 weeks, for the short-acting program, it is generally 2 weeks after the down regulation to start ovulation stimulation. It is recommended to develop good living habits, avoid overwork, and ensure regular work and rest. Regulate bad mood, keep a good mood, do not be overly nervous. Avoid the stimulation of adverse factors, which may affect the quality of eggs. Generally, 2 to 4 weeks after the lowering of the regulation can be played to promote ovulation, it is recommended to go to the local regular hospital, according to the individual situation of detailed counseling.