The follicle diameter of 18mm or more is a mature follicle, and generally, only one mature egg is expelled each month. There are individual differences in follicle development due to hormonal influences in the body, some follicles grow to 15mm and expel, some grow to 25mm and expel. The follicles are usually expelled within 1-2 days and can usually survive for about 2 days after expulsion, even if the follicles survive for a long time, the fertilization ability will be greatly reduced. Women can promote the development of follicles through dietary regimen, so that the follicles grow fast and well. You can eat more black beans and soy products in your diet, which can supplement estrogen and is very beneficial for promoting follicle development.