How to conceive a baby of your desired sex

There are various reasons why couples may wish to conceive either a baby boy or a girl. Family balance or societal pressures are some of the reasons. Rarely, there may be a medical reason why a child of a particular sex is desired.

But sex selection purely for social reasons has ethical and demographic dilemmas, and is medically illegal in many jurisdictions. However, advanced medical technology and increasing demand for sex selection have both created the need for more debate on the matter. There is a push for relaxation of the rules on a selective basis, and more couples may have a chance to pre-select the desired sexes of their future children.

Sex determination is dictated by chromosomes (structures that contain genes) carried by sperms. Females have the XX chromosome complement, while males are XY. If an X bearing sperm fertilises an egg, a baby girl is conceived. Conversely a baby boy will be conceived if a Y bearing sperm fertilises an egg. X and Y chromosomes have different characteristics, which have been exploited scientifically to predetermine sex artificially.

What to do?

So what can you do to conceive a baby of your desired sex? You will find common advise based on physical characteristics of X or Y bearing sperms. This is coupled with the timing of sexual intercourse in relation to expected time of ovulation, and with certain sexual positions being advocated to favour either a boy or a girl. Such advice is very imprecise and has not been scientifically proven to influence eventual sex of the baby. You might as well toss a coin!

More scientifically sound methods of sex selection are available, but must be combined with assisted conception techniques. Y and X bearing sperms can be separated with laser guided techniques. The desired sperms can subsequently be inseminated into the womb, with more than 90 per cent chance of success. Such techniques have long been used in commercial animal farming, but have hardly been licensed in human facilities.

In-vitro fertilisation (IVF) can be combined with a technique called pre-implantation genetic diagnosis (PGD) to preselect fertilised eggs (embryos) of the desired sex. This virtually guarantees conception with the desired sex, and has been licensed for many years in cases where a medical reason for sex selection exists. Accessing such techniques for social sex selection is limited by cost, and the law.

A less desirable option is to determine the baby’s sex soon after conception, followed by termination of the pregnancy if the sex is unwanted. This can be done as early as seven weeks of pregnancy by doing a blood test, or later with ultrasound imaging. Laws on abortion prohibit this in many countries, but the practice is still commonplace.

Couples will increasingly have choices. We can either allow natural selection to determine the sexes of our children, or use science to dictate what we desire.