Choosing to have IVF is a very careful matter for every family, so patients want to exclude all unfavorable factors and make the success rate as high as possible. When patients often come to consult about IVF-related matters, a very common question is: which month does IVF have a higher success rate? In nature, the spring and fall seasons are the best time for animals to reproduce. As humans have evolved to the point where there is no more fertility cycle, the pregnancy rate of IVF has even less to do with the seasons. IVF fertilization, culture and freezing are performed at a constant laboratory temperature and have no relation to the outside environment. Our center’s data also shows that there is no significant difference in IVF pregnancy rates in each season. Therefore, it is actually possible to choose which season to do IVF, but for patients with poor ovarian function, it is important to help conceive as soon as possible to avoid poor pregnancy outcomes due to declining ovarian function.