The follicles usually break around 36-48 hours after the ovulation injection. If the follicles are mature enough, they can break within 24 hours, the exact time varies from person to person. The follicle development process is divided into three stages: primordial follicle, growing follicle and mature follicle. Ovulation injections mainly include chorionic gonadotropin and recombinant human gonadotropin, which can encourage follicle growth, further maturation and expulsion, when intercourse can effectively increase the chance of conception. After the ovulation injection, the patient can detect the time of ovulation through ultrasound or ovulation test paper to choose the right time for intercourse. If the follicle does not break easily or if ovulation does not occur easily, it is recommended to go to the gynecology department of the hospital in time and use the treatment of ovulation-promoting drugs under the guidance of the doctor, which generally has a good prognosis. In addition, female patients should also pay attention to maintaining a stable state of mind, regular work and rest, strengthening nutrition, quitting smoking and drinking; taking appropriate amount of folic acid supplements in the three months before pregnancy and paying attention to cleanliness and hygiene during intercourse.