The frequency of follicle monitoring is usually 3~5 times, and the details vary from person to person. Follicle monitoring is usually done by vaginal ultrasound, starting on the 10th to 12th day after the start of menstruation, every 2 to 3 days before the follicle matures, and once every 1 to 2 days after the follicle reaches a diameter of 14mm or more, and then once every 1 to 2 days, and then when the follicle reaches 18mm, it is considered a mature follicle. In total, a follicle monitoring needs 3~5 times. Follicle monitoring is mainly used for women with ovulation disorders or infertility, but can also be done for women with recent fertility requirements. As there is a great deal of variability between individuals, the exact procedure and number of monitoring sessions need to be guided by a medical professional according to the patient’s situation.