On the first day of ovulation, follicles are usually visible on ultrasound. It may not be monitored if ovulation has occurred; it may not be monitored if there is no dominant follicle. If you need to monitor the follicle development, you can start monitoring the follicle on the 8th day of the menstrual cycle, until ovulation, the follicle should develop to the size of 18~22mm to be considered normal.
On the first day of ovulation, when the follicle has matured, it is the time when the follicle is at its largest size, about 18~22mm, so the follicle is visible under ultrasound. It may not be possible to monitor the follicles if they have already ovulated, or if there are no dominant follicles.
If you need to monitor the follicle development, you can start monitoring on the 8th day of the menstrual cycle, the follicle in this period is only about 5mm, the follicle grows about 1~2mm every day, and when the follicle develops to 18mm, it will be mature.
Generally, ovulation can be completed within 24~48 hours after the follicle has matured, and the egg can survive in the fallopian tube for 1~2 days. If a woman wants to get pregnant, the possibility of the egg being fertilized during this period is the highest.
If you want to monitor your follicles under ultrasound, please follow your doctor’s instructions to complete the relevant tests.