How can we know that the follicle development is normal?

Many women who are planning to have a baby are very concerned about follicular development, because abnormal follicular development has a great impact on pregnancy. What is a normal follicle like? First of all, we should understand one thing. Many women choose follicle monitoring and use B-ultrasound to measure the size of follicles. However, many people still don’t understand the test report after receiving it. The following editor will tell you about the relevant knowledge of B-ultrasound detection of follicle development.

When a newborn is born, there are about 2 million follicles in the ovaries. Only 300,000 remain near puberty. A batch of follicles develop every month during the reproductive period, of which generally only one dominant follicle can reach full maturity and release an egg.

Ultrasound manifestations of follicular development during normal menstrual cycle

(1) Time of follicle appearance:

At the beginning of each menstrual cycle, multiple follicles develop simultaneously, but generally only one or two follicles develop to maturity, called the primary follicles (dominant follicles), and the remaining follicles close one after another. The earliest time for ultrasound imaging of follicles can be 5-7 days in the menstrual cycle, and the minimum diameter displayed is 4-5mm.

(2) Follicle growth rate:

Ultrasound can reveal small follicles in the ovaries on the 3rd to 5th day of the menstrual cycle. These follicles gradually grow larger, reaching their largest size on the 14th day on average, and ovulation can occur. From the 5th day of menstruation to before ovulation, the primary follicle grows an average of 1.5mm per day; before the 10th day, it grows an average of 1.2mm per day; 4 days before ovulation, it grows an average of 1.9mm until the follicle matures.

(3) Ultrasound image of follicles near ovulation:

① The appearance rate of cumulus ova is about 20%, mostly appearing in mature follicles >18mm, and ovulation is predicted to occur within 24 hours.

② The sonic ring around the follicle is formed as the LH value rises, the membrane tissue edema, and the granulosa cells separate from the theca cells. Ovulation is predicted to occur within 24 hours. Ultrasound currently shows that the chance is very low.

③ The granulosa cells of the follicle wall are completely separated from the bottom layer of the membrane tissue, and the follicle wall appears serrated.

Now that we have a general understanding of B-ultrasound follicle testing, I believe everyone can dispel some of their concerns. Follicle monitoring is a continuous process. If the interval is too long, your ovulation may not be determined. Therefore, it is best to do ultrasound examination on time as instructed by the doctor to avoid missing the ovulation period.