Study to probe effects of choosing babies' sex

A new US trial will look at the social effects of allowing parents to choose whether they have a baby girl or boy. The study, based at the Baylor College of Medicine in Houston, Texas, will follow up babies born following the use of PGD to choose their sex. The researchers will look at social factors in the families, as well as the health of the babies, the journal Nature reports.

Sex selection for non-medical reasons is controversial in the US and elsewhere. Team leader Sandra Carson says that it took nine years to get permission to run the trial, which started last month. Although they have a waiting list of 50 couples, the researchers will only enrol those who already have a child, and want to have one of the opposite sex - a practice known as 'family balancing'.

While permitted in the US, many centres in the country do not offer PGD for sex selection. Robert Brzyski, of the University of Texas Health Science Center, says the procedure is not offered at his clinic because 'it undermines the principles of the parent-child relationship'. The American College of Obstetricians and Gynecologists (ACOG) opposes its use and the President's Council on Bioethics has also expressed concerns over the issue.

The American Society for Reproductive Medicine (ASRM) has recommended that the use of PGD solely for sex selection 'should be discouraged', because of the risks of 'unwarranted gender bias, social harm and the diversion of medical resources'. Carson thinks her study could make the ACOG and ASRM to change their positions on the issue. 'Their statements are based on public opinion, not outcomes', she told delegates at the recent ASRM annual meeting, adding 'public opinion is important, but it shouldn't be used to ban something'.

While discrimination and potential skewing of gender ratios are frequently cited as reasons not to allow parents to choose the sex of their babies, team member Paula Amato says that choosing sex to balance families is less ethically problematic. 'Most of the ethical arguments against sex selection, for example sex discrimination, are weakened when it is reserved only for the purpose of gender variety', she told the Guardian newspaper.

Permitting sex selection for family balancing reasons was cautiously approved in a recent report by the UK House of Commons Science and Technology Committee. All forms of sex selection for non-medical reasons is currently banned in the UK, following a 2003 ruling by the Human Fertilisation and Embryology Authority.