ALMOST half of South Australians believe embryos left over from fertility treatment should be used for research, a survey has found.

Another 21 per cent of the of 2693 surveyed said the leftover embryos should be donated to would-be parents.

Just 6 per cent believed they should be discarded.

"The majority of people don't want embryos to be discarded but at the same time there's a polarisation on whether embryos are human or biological cells and how they should be used," said Associate Professor Sheryl de Lacey of Flinders University, who led the survey.

The study, in partnership with the Macquarie and Adelaide universities, sought views on biological donation, particularly spare IVF embryos and organs.

The findings were published recently in the international journal Reproductive BioMedicine Online.

Other results of the research included 41 per cent of respondents to the survey considered embryos to be potential humans (33 per cent) or actual humans (8 per cent), while 39 per cent described them as biological cells. Men were more likely to consider embryos to be biological cells.

SA reproductive specialists Repromed said, on average, fewer than 10 couples a year donated embryos - fewer than 25 embryos a year.

A Repromed spokeswoman said many couples did not donate for personal reasons.

The results verified the need for a clear legal definition of an embryo and a law to specify ownership rights on unused embryos, Associate Professor de Lacey said.

She said existing laws failed to meet those community expectations or define whether an embryo was a person or property.

"The real problem is that there's no legal status for the embryo - it doesn't belong to anyone once it's out of the body," she said.

"We might see it as being the couple's embryo but there's no law that states that, so if the couple gets divorced, for example, there may be legal controversy over who it belongs to." Fertility SA embryologist Michael Barry said the existing laws worked well.

"Giving a legal status to embryos would create issues," she said.

. No one was licensed to perform research using embryos in SA, he said.

Right to Life senior executive officer Katrina Haller said all embryos should be given the chance of life and none should be destroyed.

"Having a set law would certainly clarify the situation," she said.nte