It is a moment burned into the memory of a veteran sonographer.

A number of years ago, the sonographer was asked by a couple at their scan around 12 weeks to tell them the gender of their developing baby.

“They said something along the lines of ‘We need to know the sex, because if it’s a girl we are going to terminate it’,” they said.

“You have to deal with things like terminal cancer and miscarriages when you’re working as a sonographer. But this occasion, it still sickens me to this day.”

New Australian research, revealed this month, has indicated that a group of parents could be aborting female babies because of a preference for sons. It’s led to questions over whether it is necessary to provide parents with early information about the sex of their fetuses.

Already, many obstetricians and sonographers don’t routinely provide gender information at the 12-week scan when people can still readily access abortion, largely because it’s not always accurate and there is rarely any medical purpose. Yet there is an unwillingness to follow in the path of China and India, where abortion of female foetuses is a well-identified problem, and there are bans on early gender reveals.

Advances in science and technology mean Australians are now able to find out the sex of their baby from as early as 10 weeks, via a blood test that also screens for chromosomal disorders such as Down syndrome. Others may find out their baby’s sex during an ultrasound around the 12-week mark.

While ultrasound providers have different protocols on whether they reveal the gender of the baby at the first scan, it’s the stance of the Australasian Sonographers Association that they should play no part in the debate around gender selection.

The association’s chief executive, Jodie Long, said if the sonographer was confident in being able to identify the gender, then they would provide that information if asked.

“What the parents do with information is not for the sonographer to determine,” she said

“The majority of the examination is to determine if there is an abnormality. If it is communicated to the parent that there is an abnormality, then the parents will decide what to do with that information. And that’s not up to the sonographers to determine either.”

The study from La Trobe University found that while the ratio of boys and girls born in Victoria was close to natural rates of 105 boys to every 100 girls, there are higher rates of boys born to mothers who have migrated from China and India.

For example, between 1999 and 2015, 8654 mothers born in China had boys at a rate of almost 111 males to every 100 baby girls for their second child, then at a rate of 114 to 100 to for their third or subsequent child.

“We believe that some women may be terminating pregnancies after discovering they are expecting a girl and in other cases are travelling overseas to access non-medical sex selection services through assisted reproduction,” said lead researcher Dr Kristina Edvardsson.

One experienced sonographer, who did not want to be identified, said they believed that medical professions should consider the ethics and accuracy of revealing the sex of a baby at the first-trimester scan, when an “elective termination” could still be performed.

In the past, one couple told them they would abort their child if it was a girl. As was the policy of their employer, the sonographer did not tell them the sex at the first scan, although they were so shocked by the incident, they can’t remember if they noticed if it was a boy or a girl.

“I did wonder for some time what became of that baby.”

Melbourne obstetrician Lisa Hui said she had only heard about one possible case of gender selection during her career, but most patients would be aware that it was not an approved practice, and not tell doctors about it.

“It’s very hard for us to know as professionals whether the practice is widespread. I guess that is concerning and raises it as a possibility, but we don’t have data on how fetal sex information is being used,” she said.

Nevertheless, Associate Professor Hui said she felt it was reasonable not to disclose fetal sex information at the first 12-week scan, because there was rarely a medical reason to give that information, and it was not always possible to tell the sex.

There appears to be little appetite for a formal change in that protocol that would advise doctors or ultrasound technicians against offering their best guess at the sex of a baby during the first scan or blood test.

Australia’s chief medical officer, Professor Brendan Murphy, said “it would also be unreasonable to deny access to gender information on ultrasounds for the vast majority of people who want a child of any gender”.

It’s a view shared by the man who helped draft Australia’s guidelines banning gender selection through IVF , Professor Ian Olver.

“It’s just like you can’t stop everyone from being a criminal,” he said. “You can’t stop people who are desperate to do things getting round the system. I don’t think it’s the fault of the system, and I think the society and the law is clearly anti any sort of sex discrimination.”