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As companies in the US launch bold campaigns to convince people to choose their unborn baby’s sex – and now, even attributes such as height, hair colour and intelligence – there’s a key piece of research missing.
And it’s got everything to do with you.
Selecting an IVF embryo based on sex, or screening for other traits for non-medical reasons, is not allowed in Australia. But the tide may be shifting, with US sex selection clinics organising promotional tours in Australia to lure prospective parents to their clinics.
The ruling document regulating these services is the National Medical and Research Council’s Ethical Guidelines on Assisted Reproductive Technology.
The guidelines acknowledge there is limited research scrutinising how Australians feel about sex selection. They call for wider social and political discussion, so the council may craft recommendations in line with the public’s views.
If our stance on sex selection isn’t clear, how can we be ready to consider the even thornier issue of parents choosing embryos for their chance, for instance, of turning out right-handed, blonde, tall and smart?
While the NHMRC waits for the research gap to be filled so we can better understand the public’s views on these tests, I’ve spoken to scientists, IVF doctors, lawyers and embryo selection companies to get a picture of how we might inform our thinking. Here are some of the issues that arise.
Choosing boys v girls
IVF patients can choose the sex of their embryos if it helps avoid certain diseases. Duchenne muscular dystrophy, hemophilia and fragile X syndrome, for example, affect only males – a couple with genetic risk of these diseases may, in certain cases, opt to implant only female embryos.
Otherwise, choosing a boy or girl is banned.
There’s obvious demand for that choice, though. Dr Daniel Potter, a California doctor who runs a sex selection clinic in the US, where the service is legal, spoke to at least 100 Australian couples last year who were interested in flying to the US to choose their baby’s sex.
Taking stock of the NHMRC guidelines, and the views of some IVF doctors, there seems to be less ethical opposition to allowing sex selection for someone’s third child if, for example, a couple has two sons but really want a daughter. Allowing that may encourage couples to have more kids as the birth rate falls.
Opponents worry that sex selection exerts the pressure of expectation on children. What if a couple pays $45,000 for a baby girl, dreaming of doll houses and ballet, and she grows up a tomboy or ends up identifying with a different gender?
The most relevant data I could find on whether Australians agree with non-medical sex selection is a decade old, but it found two thirds of people were opposed to it. Less than a fifth of those surveyed thought it should be legalised for “family balancing” the sex split of siblings.
Others believe Australians should be free to do what they like with their money and children.
This brings us to the more extreme end of the spectrum.
What if they’re ‘short, squat, thick and a little dull’?
The real vanguard of IVF embryo selection lies in polygenic risk-scoring. These tests attempt to take thousands of genes and generate a raft of predictions showing each embryo’s probability of living longer, being tall, getting acne, passing university or even becoming a criminal.
I wrote last week that some Australians are accessing this controversial service overseas.
The same ethical issue applies concerning parental expectations: what if you fork out thousands to select an embryo deemed to be a brainiac, and the resulting human ditches uni for the travelling circus?
Or, as one IVF provider nervous about lawsuits wondered to The New York Times, what if you chose embryos to be “tall, beautiful and smart and they’re short, squat, thick and a little dull”?
Here’s where polygenic risk-scoring diverges from sex selection. Detecting an embryo’s sex is easy. Predicting just about anything else is far harder and scientifically contested.
Unlike sex selection, which some IVF doctors are open to, most I spoke to are opposed to polygenic risk scoring for embryo selection for the simple fact they don’t think it’s accurate.
“We know that of all the variation in a particular trait, a lot of it has nothing to do with genetics,” Professor Peter Visscher, one of the godfathers of polygenic risk-scoring, told me.
“For height, it’s a bit of an exception – we think that about 80 per cent of all individual differences in height is due to genes,” he said, although even height predictions are “noisy”.
But for something like intelligence, lifespan or predicted level of education, the genetic influence is less than 50 per cent.
“Most of the variation between people is due to unknown environmental effects,” Visscher says.
That’s just one of the reasons peak bodies and scientists say the testing is not ready for clinical use.
Technology for the white and wealthy
The main issue for me is that the technology is not yet equitable. The cost (US$2500 per embryo in some cases on top of IVF costs) locks out regular folk from even considering embryo selection.
But there’s also a glaring issue in terms of racial equality. At least 78 per cent of genomic data studied by scientists across the world comes from Europeans. This is the data polygenic risk scores rely on – meaning genetic predictions are even less useful for people who aren’t European.
“We’re losing about 50 per cent of the accuracy of the scores in Asian populations, and up to 75 per cent of the accuracy is completely lost in African populations,” Associate Professor Loic Yengo, a statistical genomics expert at the University of Queensland working to fix racial inequality in the data, told me in 2024.
“We essentially won’t be able to classify [an African] person at all. That’s terrible.”
The genomic data is improving. But whether our future includes parents legally choosing which embryos to implant with a pre-imagined person in mind is an open question. A wider debate is due about this tech and what it means, really, to be human. Do we accept nature’s lottery or do we do more to control it?
For the moment, anyone weighing up this issue should consider that, at present, it disproportionately benefits the wealthy and white.
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Angus Dalton is the science reporter for The Sydney Morning Herald.Connect via X or email.