A few days ago we talked about a study in which maternal stress was related to an increased probability of having girls instead of boys. Many readers responded, both at the entrance and in the Babies Facebook group and more, that the study made no sense because the sex of the baby is determined by man, or God, or is rather a matter of chance.
As each one said a different thing and it seemed to me that it was not very clear who or what is responsible for it, today we are going to comment it, so that women and men know how the selection of the sex of the baby takes place. To do this we will answer the question:Who determines the sex of the baby: chance, mother, father, God ...?
Chance and man
As mentioned, when a couple gets a pregnancy, the chances of having a boy or girl are 50%. Well, it is not quite like that, since the percentage opts a little more towards girls, because they are the ones who will have children in the future and will ensure the survival of the species.
But well, as rounding is close to that 50%, the logical thing is to think that the sex of the baby is a matter of chance: either one touches you, or the other touches you. But nevertheless, it's not like that.
As you know, every human has 23 pairs of chromosomes in each cell. One of the chromosome pairs is the one that carries the information related to sex, being XX in case you are a woman and XY in case you are a man. Sex cells have only one chromosome. In the case of women, being XX, the eggs will always be "X". In the case of man, they can be one or the other, that is, the sperm can be "X" or "Y".
So far I have not said anything revealing, because it is normal to think that, as explained, a baby will carry the "X" or "Y" according to touch. But it cannot be so for a relevant issue: Sperm with different chromosomal loading do not have the same physical and chemical characteristics. This already breaks with the theory of chance. For sex to be determined by a matter of luck, the two types of sperm would have to be the same and do the same.
A study in which 210 families with three children each were tested. According to luck, chance, or the calculation of probabilities of 50% the probability that the three children of a family are boys is 1/8, that is, 12.5%. The probability that the three children of a family are girls is also 1/8 (12.5%). The probability that at least one of the three children in each family is of a different sex than the other two is 6/8, the remaining 75%.
If the sex of the baby was determined by chance, of the 210 families, 26.25 (1/8) families should have three boys, another 26.25 (1/8) should have three girls and 157.5 (6 / 8) they should have two children of one sex and one of the other sex. Come on, the most logical thing is that most families with three children have children of different sexes.
However, the results were very different: 73 families had three children, 69 families had three girls and alone 68 families they belonged to the category in which there were children of different sex.
How is it possible?
I know it seems weird, it seems to make no sense, because according to statistics it is very difficult that, when a result depends on a 50% chance, the result is repeated 3 times in a row. Throw a coin three times and see what comes out. It is true that on some occasion it will happen, but surely as you repeat it you will realize that it will most likely not happen. However, seeing those families, seeing mine, that I have three children, or Lola's, who has three girls, or that of Mother Tiger, who was with us for a while and has 5 daughters, it seems clear that Chance is not the cause.
Well come on, let's explain How is it possible. We have said that sperm are different. Sperm X is larger, has greater static strength, is slower, more resistant in adverse or acidic conditions and is more durable and "patient." The sperm Y is smaller, faster and numerous and requires conditions of minimal adversity, alkaline. Reach the target first but die quickly.
This means that, although the man is somewhat guilty first of the baby's sex, because one of his sperm carries the second chromosome, which will be X or Y, it cannot be him, only he who defines it, because his sperm are different and they all go together. If the ejaculations were selective and only one left spermatozoa Y and in another left only sperm X, then yes, everything would depend on man. But it is not like that, in an ejaculation there are sperm X and sperm Y and what happens next depends on what they find, or not, in the woman's body.
A woman ovulates on day 14 of her menstrual cycle, if the relationships take place on day 12, by the time she ovulates most live sperm will be X. The Y will have arrived earlier, but In the absence of an ovule, most of them will have died and the baby will be more likely. If relationships take place on the 14th, the Y's arrive earlier, and the baby is more likely to be a child.
But that is not all, according to the woman's diet, according to stress, their customs, etc., it seems that the conditions found by sperm can be different. If the mucosa is rather alkaline, it helps the Y. If it is rather acidic, it helps the X.
The one who decides is God
I wanted to comment because many also mentioned it: "what nonsense of study, it is God who decides the sex of our baby." Personally, I doubt that God is pending to choose the sex of all the babies that are fertilized in the world. Surely he has more important things to do and, truthfully, as I don't see him present even in important things, I find it hard to believe that there really is a God deciding anyone's sex. I would almost prefer more for the other options mentioned.
In summary
We can only talk about the mother, and as you have seen it has a lot to do. The father is decisive, obviously, because he carries both chromosomes, but the mother is also because she is the one that offers the means in which the union of the two gametes takes place. Depending on the conditions offered and depending on when they are, the baby will be more likely to be a boy or a girl.
So yes, I fear that the study we discussed on stress has some logic, if stress is able to change a woman's lifestyle or the conditions of her uterus, which is possible and plausible.
Photos | Thinkstock
In Babies and more | Those wonderful years: five ways to make sure a boy, 100 years ago, do you want a girl? Well, there are those who believe that you need to do all this, The possibility of choosing the sex of the baby, closer?
