What is the size of the dominant follicle?

The follicles grow during a woman's ovulation period and have a significant impact on the discharge of eggs and the chance of pregnancy. The development of follicles is different and their sizes are different. If the follicle is relatively mature, it can be called the dominant follicle. So, what is the size of the dominant follicle? Below we will introduce you to the relevant knowledge about dominant follicles!

1. What kind of follicle is the dominant follicle?

The so-called dominant follicle in medicine is a follicle that is larger than 10mm and smaller than 18mm on ultrasound. In the first half of the menstrual cycle - the follicular phase, under the action of estrogen. Usually several follicles develop successively and grow gradually. Through B-ultrasound monitoring, we find that near ovulation, there is always one follicle with the largest head, and after it ruptures and ovulates, the other follicles are absorbed and disappear one after another. We call this follicle with the largest head and the most mature development the dominant follicle. If the normal menstruation is 30 days, the follicle that grows to more than 1.0 on the tenth day of menstruation can be considered the dominant follicle.

2. Size of mature follicles

Mature follicles are one of the structural components of the ovary. The follicular cavity is large and the cumulus is prominent. The endometrial cells are close to the granulosa layer of the follicle and are separated from the granulosa layer cells by a basement membrane. The endometrial cells are polygonal, with clear cytoplasm and round nuclei. Many capillaries can be seen between the cells. The exometrial cells are located in the outermost layer, mostly spindle-shaped, and have no obvious boundary with the surrounding connective tissue. Corona radiata.

Every month, women will only release one mature egg, and this mature egg is generally considered a mature egg when it is larger than 20mm. However, there are individual differences. Some people will release the egg when the follicle grows to 15mm, while others will release the egg when it grows to 25mm. The specific individual situation can be determined by a periodic B-ultrasound examination. Generally, mature follicles will be discharged within one to two days, and the discharged follicles can generally survive for 2 days.

The influence of follicle size

The size of the follicles has a great impact on whether the follicle development is normal. If the follicle size is not standard and does not reach the normal value, it will affect normal ovulation or the quality of the discharged eggs will be poor, affecting normal conception.

The normal standard for follicle size is that the follicle is round or oval, with a diameter of 18-25mm. If it is lower or larger than the normal size, it will affect normal ovulation. Ultrasound monitoring shows that the largest follicle appears on the 10th to 16th day of menstruation. The follicle is 20mm in diameter, round in shape, with thin walls, protruding to one side of the ovary, and has good internal sound transmission. Ovulation usually occurs within 10 hours, and ovulation is more common on the 12th to 18th day of menstruation, and a few occur on the 20th to 30th day.