Some believe that male sperm are lighter than female sperm, therefore, they can be weighed or separated by centrifugation, and the sex of the fetus will be immediately apparent. Is this true?
According to experts, the father is solely responsible for the sex of the fetus. As is known, every human being has 23 pairs of chromosomes, totaling 46 chromosomes. One of these pairs is the sex chromosome. A woman has two X chromosomes, meaning that all her eggs contain only X chromosomes. A man, on the other hand, has one X and one Y chromosome, meaning that a sperm cell may carry either an X or a Y chromosome.
The X chromosome consists of approximately 150 million base pairs, while the Y chromosome consists of 60 million base pairs. However, the difference in chromosome mass has practically no effect on the overall mass of the sperm, as the latter contains much heavier organelles and components.
The shape of the sperm cell significantly affects its mass. The size of the head (whether slightly larger or smaller), the length of the tail, and the presence of a cytoplasmic droplet on the neck all alter sperm mass more dramatically than the sex chromosomes. Therefore, sperm cannot be weighed or separated by centrifugation to select a specific sex.
Currently, preimplantation genetic diagnosis (PGD) is the only method for determining the sex of the embryo. However, the law prohibits sex selection, except in cases of sex-linked genetic disorders.
