Dear doctor; My first born is a boy and now I need a girl. I am told there is a way scientists can tell if I will conceive a boy or girl. How is that possible? Anick, 26, Kigali. Dear Anick, It is fusion of two chromosomes which determine whether the child conceived would be a boy (X+Y) or a girl (X+X). Chromosomes from the father determine this. Naturally, there is 50 per cent chance of baby being either a boy or girl. But in case one decides to have a boy or girl, there are certain natural traditional methods and some advanced scientific techniques. Among the natural methods to have a girl, it is said to have coitus a little later (two to four days before) ovulation. The theory being that X chromosome, which is responsible for the baby to be a girl, is sluggish in movement as compared to Y chromosome. Intercourse done at this time will ensure that by the time ovulation occurs, the chromosome will meet the egg. Coitus done in man on top position also helps in conceiving a baby girl. Apart from this, there would be several grandmother’s tips as to how to conceive a boy or girl. However, none of these methods has backing of scientific research. Regarding scientific techniques, sperm sorting has been used effectively. Here, the X and Y chromosomes of male sperm are separated by laser light, dye and a machine called flow cytometer. Once the sperms are divided, the specimens are inserted back in the vagina and uterus by artificial means, that is, in vitro fertilisation. Pre-implantation genetic diagnosis (PGD) is useful to detect any genetic disorder in the baby to be born and can also help in deciding sex of the baby. It involves taking out the embryo from the uterus and replacing it with the embryo of desired sex. Chrionic villi sampling involves analyzing the chromosomes of the embro in early pregnancy. However, these techniques are very expensive and available in select centres only. Moreover, there are several prerequisite conditions. Also, the success is not guaranteed. American society of reproduction recommends none for being used to determine gender of a baby to be born. Dr Rachna Pande is a specialist in internal medicine at Ruhengeri Hospital
