The time needed for IVF is based on the development of the follicles. All women undergoing IVF have to go through ovulation stimulation to ensure a certain number of eggs retrieved in order to get a certain number of embryos and the possibility of transfer. For women with good ovarian function and young age, who have sensitive response to drugs, normal development of ovaries and follicles, the follicles can develop normally and can reach a satisfactory quantity and quality, and the time used will be relatively shorter, so egg retrieval and embryo transfer can be carried out as early as possible. If the patient’s ovarian function is not good, the response to a certain drug is not good, the follicles are delayed to grow or mature, and the quality of good quality follicles is not achieved, the cycle of IVF may be longer, which is mainly determined by the speed of follicle growth, or the cycle may be canceled at the end. The ultimate determining factor is how well each individual’s ovaries reflect.