Under normal circumstances, the follicle usually grows to a diameter of 20mm when it will rupture and discharge the egg, when the follicle reaches a diameter of 25mm has not ruptured and did not discharge the egg, in the clinic is mainly due to the following reasons: 1, because the body’s hormone level is insufficient, so the follicle diameter tube grows to 25mm when there is no way to rupture. 2, because of follicle wall thickness, so the follicle does not appear to rupture and cannot discharge the egg. Rupture, and can not discharge the egg, this situation is clinically known as follicular luteinization, it is recommended that you can intramuscular injection of chorionic gonadotropin, to promote the rupture of the follicle, and discharge the egg, if necessary, you can be surgically punctured follicle wall, auxiliary to help discharge the egg, and to achieve the purpose of pregnancy.