Are the chances of having a boy or girl the same?

32-year-old Chunxia gave birth to her first child four years ago. She was a baby girl. Because her family conditions were average at the time, she did not want a second child at that time.

As she and her husband worked hard, invested, and made a lot of money in recent years, their initial thoughts began to waver and they wanted to have a son.

After half a year of hard work to prepare for pregnancy, they started planning for a second child. After becoming pregnant with the second child, the doctor told Chunxia during the prenatal checkup that she was pregnant with triplets. At that time, Chunxia and her husband thought that it would be fine if they had two boys and one girl, or three boys.

But what she didn’t expect was that the three babies born after ten months of pregnancy were all girls. Now, there were four girls in the family. She and her husband were dumbfounded.

Yanhui Parenting Lecture

Regarding the second child, I think that no matter whether the second child is a boy or a girl, we should treat it with peace of mind. After all, it is our own child.

How to give birth to a son for the second time, I have some methods to improve the chances for reference.

"Old Han, Old Han, are the probabilities of having boys and girls really the same? The first four children in my family were all girls! Do you think I will give birth to a set of five golden flowers!?"

Hahaha, the secret of the legendary "Five Golden Flowers", order some coffee, and Lao Han will decipher it for you.

To talk about the probability of having a boy or a girl, we have to first talk about the "sex chromosomes" that determine whether to have a boy or a girl.

What is shown in the picture above is what is inside each of our cells. A complete set of 46 chromosomes, 23 pairs. The last pair is called "sex chromosomes". There are two types of sex chromosomes, X and Y.

Men have a pair of XY sex chromosomes, and women have a pair of XX sex chromosomes.

When carrying on the family line, the man and the woman randomly extract one of their own sex chromosomes and pass it on to the next generation.

The woman’s egg may only contain an X chromosome, while the man’s sperm may contain either X or Y. So, "It is the men who decide whether to have a boy or a girl!" This sentence has profound scientific truth

Then the question is, are the probabilities of having a boy or a girl the same? Are the legendary "Five Golden Flowers" really just a coincidence?

If something is fishy, ??there must be something fishy

The secret that determines male and female lies in the sperm of the father-to-be. Theoretically, the content of X and Y sperm in a man is the same. , so, theoretically, the probability of having a boy or girl should be the same.

The actual situation is: the percentages of X and Y sperm in each man's sperm often deviate, and the content of X and Y sperm in some people is very different.

Well, when the percentage content of X and Y sperm of an expectant father is very different, there will be a difference in the probability of giving birth to a boy or a girl each time.

For example: when an expectant father’s X sperm content accounts for 90%, then the probability of giving birth to a girl every time is as high as 90%

Under this probability, "five golden flowers" will be born "The probability is as high as 59.

So, if you want to decipher the mystery of the "Five Golden Flowers", the key is to grasp the percentage of X and Y sperm in the expectant father.

Girls who have given birth to children of the same gender in succession should pay attention to this issue. In many cases, the problem may not be as simple as "having another child".

Kill yourself and serve pregnant mothers——

Hello everyone, I am Lao Han, a flirtatious Dr. from Peking University who takes the popularization of medical science as his own duty and ideally as a friend of pregnant mothers. Korea

People are more sensitive to the issue of having a boy or a girl, but this is not a random question. It is the combination of sperm and egg, and the final phenotype is genes. The ratio of boys to girls is 1:1 in medicine, but in fact, it is not universal for everyone. For some people, it is 1.15:1; that is to say, some families have more boys than girls. This is what we have Said genetic factors.

There is a mystery to being a boy or a girl, but the mystery is not determined by fate, but by both men and women. The sex ratio at birth is generally 1:1 without artificial selection.

The gender of the fetus is determined by sex chromosomes. YX represents male and XX represents female. The human body has 23 pairs of chromosomes, 22 pairs of autosomal chromosomes and 1 pair of sex chromosomes.

The sperm and egg combine to form a fertilized egg. In this way, the 23 chromosomes in the sperm and the 23 chromosomes in the egg are paired into 23 pairs of chromosomes. If an X sperm combines with an egg, the pair of sex chromosomes in the fertilized egg will be XX, and the fetus will develop into a female; if a Y sperm combines with the egg, the pair of sex chromosomes in the fertilized egg will be XY, and the fetus will develop into a male. It can be seen that whether a boy or a girl is born depends on whether the sex chromosome carried by the man's sperm is X or Y, and has nothing to do with the egg. The sex of a child is determined at the moment of fertilization, with both parents accounting for half of the determining factor.

Scientists have studied this problem as early as the 1970s. Researchers usually use pH value to express acidity and alkalinity. When the pH value is equal to 7.0, the solution is neutral, when the pH value is less than 7.0, it is acidic, and when the pH value is greater than 7.0, the solution is alkaline. The researchers washed and soaked the two types of sperm in acidic and alkaline solutions with a pH value of 5.2 to 8.0, but the results showed that there was no significant difference in the motility changes of X sperm and Y sperm. There are also researchers who treated rabbit sperm with solutions of different pH and then conducted artificial insemination. There was no significant difference in the sex ratio of the rabbits born. Moreover, in this experiment, the sperm soaked in acidic solution were used to give birth to rabbits. The proportion of male rabbits is slightly higher, but it is not statistically significant.

It can be seen that there is no scientific evidence to support the statement that "X sperm is acid-resistant and Y sperm is alkali-resistant." Therefore, using alkaline solution to rinse the vagina will not increase the chance of giving birth to a boy. Instead, it will destroy the normal acidic environment in the vagina and make it easier to suffer from vaginitis. If you are infected with vaginitis during pregnancy, it may lead to miscarriage or premature birth in severe cases.

In fact, sperm Y is more fragile and cannot wait as long as sperm X. The closer to the ovulation period, the thinner the cervical mucus and the more alkaline it is, the more suitable this environment is for the survival of the Y chromosome. vice versa. The higher the orgasm a woman feels, the more alkaline secretions there are, and the easier it is for Y sperm to survive. In the same way, ejecting semen into the shallow part of the vagina intentionally makes it difficult for Y sperm to travel long distances, which helps X sperm to stay ahead and combine with the egg first.

There are many rumors on the Internet about having a boy or a girl, most of which are not correct. It is just a matter of chance. It is better to let nature take its course.

If it is necessary to select the gender of the fetus due to a certain genetic disease, the following methods can be used to identify it.

B-ultrasound: It can only be performed after 16 weeks of pregnancy, the accuracy is 80%, and the fetal position must be coordinated.

Amniocentesis: performed between 16 and 20 weeks of pregnancy, with an accuracy rate of 99% and a miscarriage rate of 1%.

Chorionic villus biopsy: performed at 10 to 12 weeks of pregnancy, with an accuracy rate of 99%, but a miscarriage rate of 3% to 5% and causing disability of the fetus' hands and feet.

DNA blood identification: Blood can be drawn to identify gender as early as 7 weeks into pregnancy, with an accuracy of 99.4, the most reliable.

When giving birth to a child, it is either a girl or a boy. In the eyes of ordinary people, the probability of having a boy or a girl is 1:1. However, in the eyes of scientific researchers, this data is not so accepted. Researchers are often more persistent and let the data speak for themselves. The statistical data is as follows: the probability of having a boy or girl is 106:100.

Moms with knowledge of biology will definitely not like to hear this. The gender of the baby is determined by sex chromosomes (XY). That is to say, the probability of conceiving a boy and a girl should be the same, and the probability of giving birth to a boy is The number is 6 more than that of female babies. Do male babies have stronger vitality than female babies? But the fact is a slap in the face. Female babies have stronger vitality than male babies, and the elimination rate of male babies in the womb is higher. Research suggests that the odds of conceiving a boy or a girl are 130:100. Facts indicate that the survival rate of male babies is significantly lower than that of female babies.

The above talks about the probability of giving birth to a boy or a girl in a society or a world. For individuals, some people have a 100% probability of giving birth to a boy, while some people have a 0% probability of giving birth to a boy. That is zero. Most people have a 50% chance of having a boy and a 50% chance of having a girl.

After all, individuals are idiosyncratic.

In summary, within society, the probability of having a boy or a girl is 106:100, but for individuals, the probability of having a boy or a girl is uncertain. Some can even be 100%, and some are just 100%. 0%, and even more is nearly 50%. If you don’t believe it, look at it. Lao Wang’s family gave birth to 7 children, and each child was a daughter. Good luck with your pregnancy.

Scientists who originally studied human reproduction once believed that because about half of male sperm contains (22 After the 22 X) chromosomes are combined, then approximately half should be the (22 Among them, fertilized eggs with XY chromosomes will develop into male fetuses, and fertilized eggs with XX chromosomes will develop into female fetuses. Of course, this refers to everything being normal. If that were the case, then the probability of having a boy or girl should be the same, similar to tossing a fair coin enough times and you'd get about half heads and about half tails.

Graphic: The total sex ratio of the world’s total population is 102 males:100 females. Red is an area with more males and fewer females, blue is an area with more females and fewer males, and green is an area with a very balanced ratio of males and females 1.00:1.00. Of course, this is the world's total population, not the sex ratio at birth.

Medical statisticians’ statistics on many countries or regions around the world that prohibit abortion show that in these countries or regions, the birth rate of boys is generally slightly higher than that of girls, about 101~ There are slight differences between 105 and 100 in different time periods and in different countries or regions. The birth rate of boys is indeed slightly higher, but it is usually not higher than 105.

Graphic: In 2006, the world average sex ratio at birth among those under 15 years old was 106 boys: 100 girls. Red indicates above average, white indicates average, and blue indicates countries with more boys and girls. From red to blue, the more blue the color, the more women there are, and vice versa, the more men there are. China and a few other countries and regions are very popular, which means that there must be systematic birth sex ratio selection in these places. As for the fact that some African countries are very blue, it is related to violent wars, and a large number of teenage boys under the age of 15 have died

In addition to statistics among humans, some zoologists also count the male-to-male ratio of born cubs in certain wild animals. Like humans, they use the XY pair of sex chromosomes to determine gender. Similar to findings in humans, there were also slightly more male pups than female pups.

This brings up a question, why in many animals, including humans, the birth rate of males and females is obviously biased towards 1:1. Although the deviation is not big, it is true that more males are born than females, or There are more female births than male births, of course, without artificial gender intervention, such as female fetus abortion?

In this regard, scientists in different fields have given explanations from their own fields.

Illustration: African eland and kudu sometimes die together because their horns are locked by both sides during fights

For example, zoologists like to emphasize that male animals are There will be fierce fights during courtship, resulting in male disability and mortality being higher than females. In the wild, disability and death are closely related, especially for herbivores, even if carnivores are injured or disabled, even if it is relatively minor. , will also seriously affect the hunting efficiency, and it will easily starve to death. Therefore, having more male offspring will achieve an ideal 1:1 ratio when they reach adulthood.

What is interesting is that no matter what method of reproduction animals adopt, such as polyandry or polyandry, nature prefers a sex ratio of 1:1. Evolutionary biologists explain this from an economic point of view. No matter what the specific mating pattern of animals is, the one with less sex will always be in a more advantageous position genetically, and soon the one with less sex will be in a more advantageous position genetically. will prosper, but when they exceed the balance, they will be suppressed. After thousands of years of tossing, animals will eventually make comprehensive considerations when reproducing offspring. The final sex ratio at birth will reach the adult stage. It is very close to 1:1.

If these guesses are reasonable, then we only need to count the changes in the mortality rates of men and women in the age group from 0 to 25 years old to know whether they are right or wrong. Statistical results show that it is true that men are less likely to be active at the age of 25 than women. This is true in many countries around the world. Of course, the statistics are for peaceful countries, and there are no wars and other factors that have caused a large number of teenage male deaths. Such a discovery immediately made the above The conjecture has obtained important evidence and is also the current mainstream hypothesis to explain why the birth rate of male babies is higher than that of female babies. This is a balance imposed by natural selection on humans.

Illustration: The death risk of men and women in the United States by age group. It can be found that the death risk of men from 0 to 100 years old is higher than that of women. Men especially have a significantly higher risk during the period of 15 to 25 years old. The peak of women's mortality risk. Although women's mortality risk also increased during this period, it did not rise as fast as men's. Psychologists call this phenomenon hormonal dementia in men and women. Under the strong influence of puberty hormones, men and women will do many stupid things. These things are more fatal and increase the risk of death dramatically. But men are angry at a beauty, get involved in violent conflicts, or do some particularly dangerous things in order to win a woman's smile. All of these together will increase the risk of death for men.

Theoretically, the probability of having a boy or girl is the same. This is because the woman only has one chromosome, X, which does not determine the new version. The male has two chromosomes, X and Y, which determine gender. If the fertilized egg formed by the man's X chromosome and the woman's X chromosome is a female fetus, and the fertilized egg formed by the man's Y chromosome and the woman's X chromosome is a male fetus. The male's two chromosomes determine the gender of a boy or a girl, so the probability is 1 in 2.

Although the probability of having a boy or girl is the same, the ratio of boys to girls varies in different places. There are more boys in rural areas than girls in cities. This is because of the preference for boys in rural areas. Female fetuses are aborted and male fetuses are born. Such artificial intervention by medical means has resulted in a serious imbalance in the ratio of men to women, with more men and fewer women. And region will also affect the ratio of boys to girls. In some areas, all boys are born, and in some areas, all girls are born. Those who have read Journey to the West will know that this kind of artificial intervention in the birth of boys and girls is actually not good, and it is best to let nature take its course.

1. Having sex on the day of ovulation can increase the activity of chromosome Y, allowing it to reach its destination faster and combine with the egg to form a male fetus.

On the other hand, if you want a girl, you can have sex during the safe period or the ovulation period.

2. Wash the vagina with soda water three days before intercourse to increase the alkaline environment, which is more conducive to the survival of chromosome Y. On the other hand, if you want a girl, don’t clean it.

3. The secretions produced by women during orgasm can increase the alkaline environment. On the contrary, if you want a girl, try to avoid orgasm.

People of the older generation all say that "it's up to fate to have a boy or a girl," but the scientific explanation is that the probability of having a boy or a girl is 50/50. Is this really the case?

In high school biology class, we know that the gender of the fetus is closely related to the father. It is the sperm that determines the gender of the fetus, and there are two chromosomes in the sperm, one is the y chromosome and the other is the x chromosome. If the y chromosome combines with the egg, the child will be a boy; if the x chromosome combines with the egg, the child will be a girl. Therefore, people come up with the probability that the ratio of a boy to a girl is 50/50. But this conclusion was quickly overturned by another data, that is, under natural conditions, the probability of boys being born is always higher than that of girls.

Some people think that the gender of the fetus is determined by fate, or why some families give birth to four or five girls in a row, but cannot give birth to a boy; while some people think that the birth of a boy or girl can be controlled artificially. For example, changing the pH in a woman's body, eating acidic or alkaline foods to increase the chance of having a boy/girl, having sex before ovulation or after ovulation may change the gender of the fetus, etc. There are a lot of articles about this kind of thing on the Internet, and many netizens have personally confirmed it.

Many parents have different opinions on the probability of having a boy or girl.

For example, the leader of Happy Dad, who is also the director of our department, just welcomed his third baby girl this year. With the two golden flowers for the eldest and second child, there are already three golden flowers at home. He actually really wanted a son, but if things didn't work out, the girl couldn't help it! Another colleague's first child is a son. Some time ago, the country allowed the second child. They are also very excited and want to win again. If it is a daughter, wouldn't this be a son and a daughter? Isn't it the standard in many people's minds? As a result, the second child was born with a son, two CCBs.

From a genetic perspective, it is the same; but from a human individual perspective, it is different.

First, let’s talk about the probability issue of genetics. Everyone's cells have a complete set of 23 pairs, or 46 chromosomes, of which the last pair, the 23rd pair, is called the sex chromosomes. As the name suggests, this pair of chromosomes controls a person's gender. The male pair of chromosomes is an XY combination, while the female pair of chromosomes is an XX combination.

When giving birth to the next generation, men and women each randomly extract one of their own pairs of chromosomes, and when combined with the other's chromosomes, the sex of the child is determined. For men, there are two possibilities: X and Y, while for women, there is only one possibility: X. Therefore, the decision to have a boy or a girl can only be made by men. Those movies and TV shows that often say that mothers are weak and unable to give birth to a son are actually nonsense. The only person who determines the gender of a child is the father.

From this perspective, the probability of having a boy or girl is the same, both 50%.

However, in fact, for men, the ratio of X and Y chromosomes in sperm is different, which has a certain relationship with their workplace, physical condition, and even living habits. For example, when the X chromosome in some men's sperm accounts for 80%, the probability of giving birth to a girl every time is 80% or even higher. So we can see in real life that some families will never be able to stop having daughters until they have a daughter. This is the reason why.

It’s different. Our ancestors said: Mountains give birth to boys, and swamps give birth to girls. There is a certain truth to this. Mountainous areas mostly have an alkaline living environment, while swampy areas mostly have an acidic living environment. It is scientifically proven that the x chromosome is suitable for acidic environment and the y chromosome is suitable for alkaline environment. If you want to know more details, please contact me and I will give you tutoring lessons starting from the first grade.

The neighbor’s aunt gave birth to six children, three boys and three girls, one girl and one boy born apart from each other. Some people in the village said this is called separated flowers, separated children.

The aunt’s children, especially daughters, were not so lucky:

After her eldest daughter Caicai got married, she gave birth to five girls in a row, and the family was poor. I heard they were divided. Three were given to others, and the youngest was taken to her parents’ house to be raised by her aunt. The sixth is the son.

The eldest son is okay, a son and a daughter have completed the task.

The second daughter wanted a daughter so much, but both of them were sons. In the end, she took a daughter from her younger sister to raise.

The second son went out to work and gave birth to a son. He said he was too stressed and stopped giving birth.

The third daughter, Qiuqiu, gave birth to three daughters. She raised the first two by herself, and gave the latter to her sister to raise. She also had three miscarriages due to various reasons. However, at nearly 40 years old, she still wants to have a son. , so she got pregnant again, but she didn’t know if it was a boy or a girl. If it was a girl, Qiuqiu didn’t know if she would get another one.

The third son gave birth to two daughters and a son, so he was considered lucky. Originally I only planned to have two children, but because the probability of having a girl was high, I gave birth to three. The pressure was also greater than that of ordinary people.

If you look at the aunt's family, the 6 children gave birth to 17 grandchildren, 6 of which are boys and the other 11 are girls. The equivalent male to female ratio is 100:183

But globally, the male to female ratio is between 102:100, which means that the proportion of boys born is generally a little higher.

Looking at China, it used to be between 106:100. Because China’s preference for sons over daughters may have caused some baby girls to die before they were born, it has now reached the ratio of men to women in China. According to data, studies have found that the ratio of men to women in China It has reached 112:100.

Let’s go to the kindergarten and have a look. It seems that there are indeed more boys than girls.

So generally speaking, the birth rate of boys is slightly higher than that of girls.

According to scientists’ research, this is caused by human beings trying to perpetuate their genes. The probability of boys dying unexpectedly from childhood to adulthood is much greater than that of girls.

From a broad perspective, the birth rate of boys is higher than that of girls, but it does not necessarily apply to everyone. Some people give birth to several boys in a row, and some people give birth to five or six boys in a row. girl.