What are the chances of you choosing your baby's sex?

"The surest way to conceive a baby of a particular sex is through the use of technology," says Dr. John Ong'ech, a reproductive health specialist at Kenyatta National Hospital.

"In developed countries, doctors have at their disposal technologies that can allow isolation of sperm cells with sex determining chromosomes," he says.

The sex of a baby is determined by X and Y chromosomes. Women carry two X chromosomes and men carry an X and a Y.

Female gametes all have the X chromosomes. Sperms on the other hand can carry either the X or the Y chromosome, hence the understanding that men – and not women, have the magic wand that determines the sex of a baby.

"Isolating sperms means that an egg can therefore be fertilized by a sperm with a specific chromosome: if the sperm has the X chromosome the baby becomes a girl and if the sperm carries the Y chromosome then the baby is a boy," Ong'ech says.

Besides technology, there is really nothing else with as much rate of success.

Through normal intercourse it becomes difficult for a couple to determine the sex of their baby.

Hope rests on the most commonly touted natural method which involves having intercourse three days before ovulation and zero intercourse after ovulation if the aim is for a girl.

To have a boy, a couple would need to have intercourse only on the day of ovulation.

"The sperm that has a Y chromosome is smaller and faster than the X-bearing sperm. It however survives for a shorter period of time compared to the X-bearing sperm," Ong'ech says.

The theory goes that right at the time the egg is released, the fastest sperm that gets to the egg is the Y-bearing sperm and hence end up with the conception of a boy.

Ong'ech puts the success rate of this natural method of sex selection at around 60 per cent.

There are other theories ranging from dietary advice and sex positions which the medic says have very little or no scientific basis.

Ultimately, he says, sex selection is the function of biology and not quite easy to be influenced by man in the absence of technology.