The maturity of the follicles is usually known by doing follicle monitoring with ultrasound. If you have a regular menstrual cycle, you can start monitoring on the 11th-12th day of your period. The first step is to check whether there are any problems with the ovaries, the uterus and whether there are any dominant follicles, and if there are dominant follicles, they need to be monitored regularly. If the endometrial lining is 0.8 cm thick and the follicle is 1.8 mm or more during the ovulation period, it indicates that the follicle is mature, and after maturation, we need to observe whether the follicle is round and whether the internal sound is good. If the internal sound transmission is good and the follicles are round, it means that the follicles in the ovaries are mature and good. The mature follicles should be monitored again, usually 1-2 days later, to see if the mature follicles can be expelled. If they can expel, it means that ovulation has already occurred this month. At this time, if you have the requirement to prepare for pregnancy, you can have intercourse and prepare for pregnancy during the ovulation period, which is usually tested after 2 weeks to see if you can get pregnant successfully. To determine if the follicle is mature, we mainly look at the size and shape of the follicle, and we can also determine the echogenicity of the follicle. If the follicle is above 1.8mm, with good internal sound transmission and rounded follicles, it indicates that the follicle is mature and if it can be expelled after maturity, the chance of pregnancy is very high.