Non-invasive prenatal testing (NIPS) is available in the US and blood tests from Australian women are at present sent to America for screening at a cost of about $900.

From the end of next year, Victorian pathology company VCGS plans to make the test, where foetal DNA found in the mother's blood is screened for chromosomal disorders, available across Australia.

The test is primarily used as a more reliable indicator during the first trimester of whether an unborn baby has Down syndrome.

It does not carry a risk of miscarriage, unlike amniocentesis and chorionic villus sampling, the two tests used in Australia.

But ticking another box on the form also tells parents the sex of their unborn child.

In a review of the test published in the Royal Australian and New Zealand College of Obstetricians and Gynaecologists magazine, Australian National University associate Professor Steven Robson raised concerns about couples using the test to ''gender balance'' families. NIPS can determine gender from nine weeks.

''The potential downside of this test is you can tell the sex of the baby, very accurately, and as we know in a number of countries in particular female babies are subject to termination,'' Dr Robson said.

But UNSW associate professor Gavin Sacks said this was not a concern in Australia and it would not change the demographics of the country. ''I think finding out the sex is everyone's right, the technology is there you can't dis-invent it … and I've never yet come across anyone who's gone for the test and chosen to terminate on the basis of that result.''