A REPORT in the Australian Daily Telegraphon March 13th alerted readers that, "Australian couples may soon be able to choose the gender of their children for purely cultural reasons or just to balance their family". The Australian National Health and Medical Research Council will consider opening up access to technology that allows gender selection of the embryo before it implants in the mother's womb, writes WILLIAM REVILLE
This issue has obvious social and ethical implications and is a good example of how advances in scientific knowledge and technology constantly challenge society to find acceptable outlets for their application. Gender selection is legal in most of the world, but not in Europe. Obviously it is only a matter of time, and probably a short time, before this matter comes knocking on our door.
The gender of the unborn baby can be predetermined by using either of two types of manipulation before the embryo implants in the mother’s womb – sperm sorting or preimplantation genetic diagnosis (PGD). Sperm cells come in two varieties depending on the sex chromosome they carry. About half the sperm cells in an average sperm sample will carry the X chromosome and the other half will carry the Y chromosome. If the female egg is fertilised by an X sperm the resulting embryo will be female – if the egg is fertilised by a Y sperm, a male embryo will result. Sperm sorting means separating the X sperm from the Y sperm. Once the sperm sample has been sorted, either the X or the Y half, depending on the desired gender outcome, is placed in the woman’s body (intrauterine insemination) just as she is about to ovulate. About 92 per cent of those attempting to conceive a girl by this method and about 87 per cent of those attempting to have a boy, are successful.
The PGD procedure is carried out in an in-vitro fertilisation (IVF) clinic. Eggs are collected from the woman and fertilised in the laboratory with her partner’s sperm to produce embryos. The sex of the embryo (XX – female or XY – male) is established at conception. The embryos are allowed to develop in the laboratory for five days, at which stage they contain about 100 cells (the blastocyst stage). The blastocyst contains two types of cells – the “inner mass” that will go on to become the baby and the trophectoderm that will go on to form the placenta. Three or four cells are removed from the trophectoderm and are tested to determine whether the embryo is male or female. Only embryos of the desired gender are implanted in the woman’s womb. This PGD technique is almost 100 per cent accurate.
Gender selection is an area hedged by many ethical considerations. These considerations include: potential for inherent gender discrimination, unjustified use of limited medical resources, using the child to fulfil parents’ expectations rather than respecting the child as a person in his/her own right, and more. Some people also fear that PGD is a “slippery slope” that could lead to full-scale eugenics.
The conventional natural method of conception regulates gender balance at about 50:50. Such a balance is very important for biological and social reasons. Artificial sex selection could significantly alter the natural ratio of females to males. Fears are often expressed that gender selection would lead to a significant preference for boys. But, experience to date in the US using the sperm sorting technique has not confirmed this fear.
Many parents have an understandable desire for a degree of gender balance amongst their children. For example you wish to have four children and you already have three boys, so you would dearly like the fourth child to be a girl. Sperm sorting is used in such cases by many couples in the US to achieve gender balance in their families.
To deliberately choose the gender of your child seems to offend the Kantian principle of respecting the child as a person and an end in their own right. But, Kantian principle aside, I wouldn’t have another major objection with gender selection for family gender balancing using the sperm sorting pre-conception method. However, my instinct tells me that gender selection is not intrinsically important enough to persuade us to stray from the natural method of conception. I could not favour the PGD method since it generates unwanted embryos.
And finally a pertinent personal story comes to mind. Some years ago I was helping a frail, elderly woman to find a live-in housekeeper who would also assist her with her personal care (safety in the bath, etc). The housekeeper had to be female for obvious reasons, but the newspaper refused to accept an ad that specified gender. One wonders how any society that fusses so unreasonably about gender discrimination could even contemplate deliberate pre- determination of the sex of a baby.
William Reville is associate professor of biochemistry at UCC. understandingscience.ucc.ie