In order to reproduce excellent offspring, the human physiological mechanism has made painstaking arrangements. It uses the two most important methods: one is to select the excellent, and the other is to eliminate the backward.
These two methods run through the whole process of childbirth, exist everywhere, and always exist, making you feel very wonderful and incredible when you think about it.
◎ Select excellent sperm
We observe the competition of sperm, it is like a marathon race, and its intensity far exceeds this long-term competition. distance sports competition.
At the beginning of the competition, all the athletes set off together, and it was so majestic and thousands of heads were surging, it was very spectacular! But after a short run, a gap appeared. Several phalanxes with different speeds were formed. The more energetic phalanxes gradually separated from the main group and took the lead, while a large number of weak ones fell behind. Slowly, this gap will become wider and wider, with fewer and fewer people running in front and more and more people falling behind!
Finally, we saw an athlete running into the stadium first and rushing to the finish line. This was the best among hundreds of millions of sperm.
◎ Select excellent eggs
The selection of eggs is like a job fair. When a recruitment notice is posted, there will be Many people submitted application forms and expressed their willingness to compete for this position.
The follicle stimulating hormone (FSH) in the female sex hormone, at the beginning of the menstrual period, due to the decrease of estrogen and progesterone, suppresses the hypothalamus. At this time, the FSH value will reach a peak. At the same time, a batch of egg cells came to register. At this stage, there are always several or a dozen follicles developing at the same time in the ovary.
But which of these several or dozen follicles is the most suitable? The most commonly used methods in talent recruitment are interviews or written tests to see who is the most qualified. The endocrine system adopts a very strict death policy for the selection of follicles. After the peak, FSH will immediately drop to a very low level. At this time, the follicles with poor quality will not be able to withstand the suffocation of low FSH levels and become atretic, while those with more \” One follicle of the \”receptor\” can withstand harsh conditions and continue to mature, and is finally discharged under the action of the double peak of FSH and luteinizing hormone (LH). This egg is certainly the most capable among the candidates.
Each woman usually releases one egg every month, and this egg is selected from many follicles that come to apply. So, is there definitely one or only one follicle every month?What about development? The actual situation shows that this is not necessarily the case!
FSH reduces the level during the follicular phase in order to cause many unqualified follicles to become atretic. However, among the many follicles, there may be two follicles that pass the death test at the same time! Then, sisters will find that there are two or more dominant follicles developing at the same time in the ovaries during B-ultrasound examination.
On the contrary, if there is no follicle that can pass the strict test this month, all the follicles will be atretic! Then, you will not see the presence of dominant follicles during the B-ultrasound examination, so it is impossible to ovulate this month.
One follicle develops, multiple follicles develop, or no follicle develops. No matter which situation occurs, sisters should understand that this is the normal result of a \”talent recruitment fair\”!
Everyone will be happy if they see two dominant follicles developing at the same time. Because the chance of conception increases, and there is even the possibility of twins, which is really a beautiful thing. Sisters who do not find dominant follicles will be very frustrated, and may even panic, thinking that there is something serious wrong with their body, and rush to the hospital for various examinations. In fact, there is no problem at all. It is very normal to occasionally not ovulate for 1 to 2 months out of 12 months in a year. This does not mean that there is an endocrine problem. As long as the ovulation does not occur for several consecutive months or for a long time, there will be no problem. . If there was very normal ovulation last month but not this month, it just means that a qualified \”talent\” was not recruited this month.
It is very common for follicles to develop. Every woman of childbearing age usually has one follicle that matures every month. It will be discharged when it finally grows to a suitable size. What is the right size? There is no absolute constant size. Follicles are generally discharged when their diameter is 1.7 to 2.3 centimeters. If the diameter exceeds this range, for example, if the diameter is less than 1.6 centimeters, the follicles are not yet mature, and ovulation is a small follicle; if it exceeds 2.5 centimeters, the follicles are too mature, and ovulation is a large follicle. Whether it is ovulation by a small follicle, ovulation by a suitable follicle, or ovulation by a large follicle, as long as it is released, the egg can generally be fertilized and become a fertilized egg, enter the uterus through the fallopian tube, and attach to the uterine wall.
◎ Eliminate unqualified fertilized eggs
The process of implantation of fertilized eggs is very complicated. So far, experts are still studying it, but for After the fertilized egg enters the uterus, it has gone through three steps: attachment, positioning and implantation.
For a fertilized egg to develop, it is important to first be able to attach to the wall of the uterus. As mentioned earlier, due to the changes in the endometrium during the secretory phase, many protrusions have grown on the surface. At the same time, the surface of the uterine wall is rich in carbohydrate-rich organic molecules and the \”L-selectin\” on the surface of the outer cells of the early embryo. The proteins adhere to each other, causing the embryo\’s movement speed to gradually slow down and finally stop after entering the uterus.
This movement process of early embryos is likeAs a tennis ball rolls across a surface filled with syrup, the embryo\’s journey along the uterine wall will eventually be terminated by this mutual adhesion.
The time for the real test has arrived! The fertilized egg can stick to the uterine wall, but it may not be able to implant into the endometrium.
There are two difficulties. One of them is the sensitive period of the endometrium. The carbohydrates on the surface of the uterine wall reach a peak in a short period of time. Only during this period can the early embryos possibly germinate. It doesn\’t matter if you get out of bed too early or too late. It\’s like the office hours of an organization. Visitors are only received during office hours.
The second difficulty is that although it is during office hours, the office door is locked, and the fertilized egg has to find a way to open the lock before pushing the door in. The endometrium does not naturally accept the implantation of fertilized eggs. The fertilized eggs must continuously secrete enough proteases to be able to dissolve a hole in the endometrium. Unqualified fertilized eggs are often eliminated here because they Without the ability to open the office door and the high investment (expensive), it is usually (and should be) postponed until after the 2nd or 3rd miscarriage, and there is no need to do a chromosomal analysis on the first miscarriage.
When deciding whether to perform chromosome analysis, you should consider the following: young couples are less likely to have chromosomal abnormalities than older couples; and couples who live and work in strong radiation and strong electric field environments are less likely to have chromosomal abnormalities than older couples. Couples living and working in a normal environment are much older!
Most of the embryos eliminated in the first trimester are weak fertilized eggs, formed from aging sperm (which have existed for three or four days before fertilization) and aging eggs (which have been discharged for 24 to 48 hours). The embryo is prone to miscarriage. It is generally difficult for a weak fertilized egg to implant, but some are lucky enough to implant successfully. After the fertilized egg implants, the embryo\’s trophoblast cells will immediately secrete HCG, and the rate will nearly double every two days.
The aging fertilized egg does not have the ability to produce enough HCG, and HCG increases very slowly. When measured in blood β-HCG, although it is sometimes at a normal value, it must be at a low level, or even have a continuous downward trend. This is The situation is very worrying!
The above-mentioned reasons for miscarriage or fetal termination are embryonic. For women, it is really lucky to have a fertilized egg with strong vitality. It can make up for many shortcomings of the mother and make your entire pregnancy smooth. Good luck!
This article is provided by Baidu Reading and is excerpted from \”Pregnancy Can Be Simple\” Author: Feifei Mom