Before IVF, the woman will be given ovulation medication so that the ovaries can have as many follicles as possible to develop, and then the eggs will be retrieved. If more eggs are retrieved, the success rate of IVF will be higher. The number of normal eggs retrieved varies depending on the age group and the function of the individual’s ovaries. For example, some women who are younger and have normal ovarian function may have a dozen or even two dozen follicles developing after ovulation, so they may be able to retrieve a dozen or two dozen eggs. In some cases, the ovaries are prematurely failing and there is not much reserve in the ovaries, so only 2-3 follicles may develop after the ovulation medication and only 2-3 eggs can be retrieved. In some patients with polycystic ovary syndrome, the ovarian reserve is relatively high. In these patients, if the medication is used, the patient will try to control the ovarian reserve and not to let too many follicles develop, so that the estrogen level in the body will be too high and the risk of ovarian hyperstimulation syndrome will increase. Ovarian hyperstimulation syndrome is a condition in which the patient will develop pleural fluid, ascites, bloated stomach, general discomfort, and even some people will need to be hospitalized for treatment, which will be controlled to try to have about a dozen eggs. So for those with average ovarian function, the dose of medication needs to be high to get as many eggs as possible, and for some patients with very good ovarian reserve it will be controlled to not have too many follicles developing. In short, the goal is to get a dozen eggs, about 10-15 eggs, because statistics show that getting about 10-15 eggs is basically enough for IVF to have one and two children, too many eggs to use up on their own, too many eggs to take, the risk of ovarian hyperstimulation will increase at the same time. If too many eggs are retrieved, the risk of ovarian overstimulation increases. If too few eggs are retrieved, the probability of forming good quality embryos is low, which has an impact on the success rate.