When is the follicular development phase?

Women are born with primordial follicles. Newborns have 700,000 to 2 million primordial follicles on both sides of the ovaries. By puberty, there are about 40,000 primordial follicles. Only when women ovulate normally and meet sperm can a fertilized egg be formed and pregnancy be possible. The development period of the follicles begins at an early age, but many women may still be infertile. This is very strange, so the editor will explain it below.

Generally, ovulation will occur when the follicle reaches 20MM or more. Generally speaking, the ovum is released about a week after menstruation. What is the normal size of the follicle? When monitoring ovulation with ultrasound, if the follicle is underdeveloped and the egg is not released normally, it will affect fertility.

Ovulation occurs during each menstruation. The ovarian cortex is composed of an oocyte and many small follicular cells around it. The development of follicles takes a certain amount of time. According to the morphological and functional changes during the follicle development process, it can be divided into three stages: primordial follicles, growing follicles and mature follicles.

During this process, the follicles seem to need "warmth" from the outside world to promote their own development and maturation. 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. There are usually one or more follicles. But usually only one mature egg is released each month, while the others atrophy or are absorbed by the body.

Mature follicles may show the following characteristics:

1. The follicle is round or oval, with a diameter of 15-30mm (21.2+-0.53mm). The follicle is echo-free, clear and pure, with clear boundaries and thin walls.

2. One day before ovulation, 20% of mature follicles can be seen in the cumulus image, which appears as a short and strong echo near the wall of the follicle. Under normal circumstances, a person's follicles are considered mature when they are above 20 and can be discharged.

If the follicles are underdeveloped and cannot ovulate, forcibly using ovulation-inducing drugs in a short period of time to force ovulation will cause the eggs to be released, but they will be immature and therefore cannot lead to normal conception. Even if the sperm and egg combine, miscarriage, stillbirth, etc. can easily occur. It is recommended that women with health problems should not rush to have children, and should consider it after their health has recovered.