Women are born with primordial follicles. Female newborns have 700,000 to 2 million primordial follicles on both sides of their ovaries, and there are about 40,000 by puberty. A small number of follicles may occasionally grow during fetus and childhood, but they cannot mature. Starting from puberty, under the influence of gonadotropins periodically secreted by the pituitary gland, one follicle matures and releases an egg every 28 days. The left and right ovaries ovulate alternately. A woman will ovulate more than 400 eggs in her lifetime.
So, everyone should know that follicles develop and mature under the action of gonadotropins. Without gonadotropins, they will become a group of children who will never grow up!
Follicles are composed of oocytes and follicle cells. Follicle development is a continuous process and can generally be divided into four stages: primordial follicles, primary follicles, secondary follicles and mature follicles. Primary follicles and secondary follicles are collectively called growth follicles. In the past, we generally believed that the development of primordial follicles to mature ovulation was completed within one menstrual cycle. However, recent research has proved that the follicles actually grow slowly. It takes several times for a primordial follicle to develop to mature ovulation. The menstrual cycle usually takes a long time of 85 days to complete. We know that it takes 90 days for sperm to mature. Therefore, raising a new life is definitely not an easy task and requires parents to prepare for a long time!
We do not need to understand the entire process of follicle development in detail, we only need to master a few important aspects of it. The growth from primary follicles to mature follicles can be divided into 8 levels. The first 5 levels are too small and take too long to grow, so they have no practical significance. Starting from level 6 is the focus we should pay attention to.
The diameter of the sixth-level follicle is 5 mm; after 5 days, it grows to 10 mm and becomes the seventh-level follicle; after another 5 days of development, it becomes the eighth-level follicle, with a diameter of 16 mm . Level 8 follicles are mature follicles! Therefore, it takes a total of 10 days from the sixth-level follicle to grow to the eighth-level follicle, which is exactly the follicular phase of a menstrual cycle.
After 2 to 3 days, the 16-mm level 8 follicles will develop into 20-mm follicles, which will release eggs under the stimulation of LH (luteinizing hormone).
What is the use of knowing the grade of follicles? If we regard the 6th level follicle as \”junior high school\”, the 7th level follicle as \”high school\”, and the 8th level follicle as \”college\”, then it means that once the follicle exceeds 16 mm, it is equivalent to \”college graduation\” ,16Millimeters are the critical size of mature follicles.
The diameter of the sixth-level follicle is 5 mm, which has no practical significance. Just like our country implements a universal compulsory education system and every child must receive junior high school education, the average follicle will reach this size!
The diameter of level 7 follicles is 10 mm. We found that in high school, more people drop out of school. Therefore, multiple follicles in patients with polycystic ovary syndrome are often atretic below 10 mm.
When the diameter of the follicle reaches more than 10 mm, it enters the \”college stage\”. At this time, the follicle will develop abnormally. Their development direction is generally:
◎ Normal development until \”graduation from college\”;
◎ \”Leaving school\” early, with the discharge of small follicles;
◎ Atrophic and luteinized small follicles appear.
So, within 16 mm is the changeable period of the follicle!
This article is provided by Baidu Reading and is excerpted from \”Pregnancy Can Be Simple\” Author: Feifei Mom