Each year in Australia, hundreds of couples fly overseas, usually to the United States, so that they can choose the gender of their child through in-vitro fertilisation, which allows them to implant an embryo of the right sex.
Sex selection is banned in Australia, except in rare cases where a child may otherwise be at risk of inheriting a serious genetic condition.
But there is a push to allow so-called sex selection in cases of "family balancing", where couples already have numerous children of the same gender. It is believed about 70 per cent of couples who currently travel abroad for gender selection do so to have a girl, typically after already having had two or three boys. The estimated cost of doing this in the United States is about A$35,000 (S$32,840).
A group of parents, called Legalise Family Balancing, is pushing to allow sex selection for families with two or more children of the same sex. It has written to 100 MPs and to the National Health and Medical Research Council (NHMRC), Australia's peak medical council, to urge that the ban be removed.
According to a report in ABC News, the group says "gender desire causes genuine and, at times, severe distress in those experiencing it". "Restricting sex selection is effectively denying Australians access to what would be an effective means of alleviating this distress," the letter says.
The push has been backed by some doctors and medical clinics, who say it is unfair to deny parents a choice when the medical procedure is readily available and straightforward. But surveys indicate most Australians are opposed to it.
A survey in 2016 found about 75 per cent of Australians opposed sex selection for family balancing. About 19 per cent thought it should be available for choosing the sex of a third child, with the remainder refusing to provide an opinion.
In 2017, the NHMRC banned gender selection for non-medical purposes in its official guidelines for reproductive clinics. It indicated it was open to a change but this would depend on shifts in public opinion or the views of governments.
A study last year by Monash University found opposition to sex selection had in fact strengthened in the past decade.
Percentage of Australians in a 2016 poll who opposed sex selection for family balancing. About 19 per cent thought it should be available for choosing the sex of a third child.
"Clearly, the Australian community does not accept the practice of social sex selection," it said.
"If regulatory change is to be guided by societal attitudes, then the prohibition against sex selection for non-medical reasons should remain in place."
Some opponents of sex selection believe it would pave the way for other forms of genetic selection.
Dr Bernadette Tobin, from the Plunkett Centre for Ethics at the Australian Catholic University, said she believed love should be "unconditional". "Once you allow sex selection for non-medical reasons, I think the gate is open for any reason at all," she told ABC Radio's Religion and Ethics Report last week.
Separately, a heated debate has occurred in recent days in New South Wales (NSW) over whether Parliament should specifically ban abortions based on gender selection.
This followed a move by the state government to decriminalise abortion. A 119-year-old law outlawing abortion remains on the books in NSW, though abortion has long been widely practised in the state and most people are unaware it is illegal.
However, the move to formally remove the anti-abortion laws was opposed by some conservative MPs, who then pushed to include a specific ban on abortions for sex selection. Such abortions are believed to be carried out in countries such as India and China, where some parents illegally practise abortions to ensure they have boys.
NSW Premier Gladys Berejiklian said that according to advice from the state's chief obstetrician, the practice was "not an issue in New South Wales". However, she said she was open to supporting a ban on the practice because "we should be seen to be doing the right thing".
"If there is more we need to do to actually allay concerns of the community, of course we will," she said last week. "Everybody regards gender selection as abhorrent."
An inquiry into the abortion Bill is due to release its findings on Tuesday. Parliament will then finalise its vote on the Bill.