A frequent question I get to respond to in my clinic is –Dr how do I get to select the sex of my baby?. My usual response to them is to find out if they want the truth or a sensational answer.
In some parts of Nigeria, Male babies are preferred to female babies. This is to ensure that the family name and dynasty is maintained. Some individuals will prefer to have a balance ratio of male to female distribution in their families. There are social and ethical implications of sex selection, but I don’t intend to bore you with the details of this.
My goal in this discussion is to explain the scientific basis of sex determination so you can distinguish what the true answer is from the sensational answer.
The union of the male sex cell (sperm) with the female sex cell (ovum), leads to the formation of a Zygote(future Baby) .Weather the baby will be a male or female baby depends on the chromosomes carried by the male and female sex cells. The male sex cell (sperm), is solely responsible for sex determination because it has the capacity to carry X and Y chromosomes. The ovum (egg) can only carry X chromosomes and as such cannot help determine sex.During formation of a baby, should the male contribute a Y chromosome carrying sperm, the baby will be a boy. On the contrary, if the man contributes an X carrying sperm, the baby becomes a female baby.
The question is, what determines if the male will send an X carrying sperm or a Y carrying sperm?.The answer will depend on if it is a natural conception or an artificial conception.
In natural selection, some researchers believe that the Y chromosome carrying sperm tend to move faster than the X chromosome carrying sperm and as such should intercourse occur just before ovulation, the Y chromosome
carrying sperm will be the fastest to cause conception and thus a baby boy will result. The reverse will obviously be the case should intercourse take place immediately after ovulation. This postulation depends on the ability to
accurately determine ovulation which is not sacrosanct. Unfortunately this postulation is not scientifically correct and so it is a sensational answer.
Varied positions used for sexual intercourse does not help select a particular sex of a baby.
In artificial conception, it is however possible to select the desired sex of a baby by subjecting harvested spermatozoa to flow cytometry and picking out the desired spermatozoa for intrauterine insemination, invitro fertilization or intracytoplasmic sperm injection. This is known as sperm sorting.
In Preimplantation Genetic diagnosis (PGD), sex selection is done by using embryos resulting from IVF procedures and then genetically tested for X or Y chromosomes. The embryos of the desired sex are then implanted. Ethical and moral issues are elicited in this situation, because undesired embryos may have to be discarded.
In conclusion,sex selection in natural conception is a chance event.In artificial conception,it is possible to desire and select a particular sex of baby.
