The sex of the fetus depends on whether the sperm carries an X or Y sex chromosome. Do you want to know why? Let us tell you:
What is the genetic difference between a boy or girl embryo?
In each of our cells, humans have 23 pairs of chromosomes (46 chromosomes in total).
The pairing of 23 chromosomes in women: XX.
The pairing of 23 chromosomes in males: XY.
Are you having a boy or a girl according to genetics
First, we need to talk about gametogenesis, which is the process by which gametes are generated. That is sperm in men and eggs in women.
These gametes, i.e., egg cells and sperm, each has 23 chromosomes. Therefore, when sperm fertilizes an egg, they form a zygote with all 46 chromosomes, 23 from the mother and 23 from the father.
Women always have an X sex chromosome because, as explained above, females have two X chromosomes. However, sperm can have either an X or a Y chromosome. If a sperm with an X chromosome fertilizes an egg, this will be female (XX). But if the sperm that fertilizes the egg has Y chromosome, the zygote will be male (XY). So, the likelihood of having a boy or a girl depends on whether the sperm that fertilizes the egg is X or Y.
What factors can influence this process?
Now that you know how human sex is determined, you must know it’s a random process. Still, some studies suggest that the probability of what will you have a boy or a girl is influenced by the day you have intercourse about ovulation.
This is because sperm with an X and a Y copy has some different characteristics:
Y sperm are faster but survive less time in the female genital tract.
X sperm are slower but more resistant and therefore survive longer.
Can you ‘choose’ the gender?
As we mentioned above, there are two hypotheses that can affect the probability of having a boy or a girl:
Speed. Because sperm containing the Y chromosome are faster than those containing the X chromosome. The Y sperm are more likely to reach it and fertilize it, meaning that the baby is more likely to be a boy.
Longevity. Sperm that contains the X chromosome can live longer in the female genital tract. The sperm with the X chromosome will be able to survive longer, and this increases the chance that it will be a baby girl.
These hypotheses explain that if intercourse takes place when ovulation has already occurred, the Y chromosomes will reach the egg sooner, while if it occurs before ovulation, it will increase the chances of having a girl. The X chromosomes can survive longer until the egg reaches the fallopian tubes.
However, remember that these are just hypotheses, and even if you know when you ovulate (which you can find out with the help of an ovulation test) and want to try, there is no guarantee that the baby will really be one gender or the other.
