SYDNEY women are importing sperm from the US because Australian men are too scared to donate.

Local donations to IVF clinics have all but stopped since it became easier for children to track down their biological fathers.

IVF Australia head Professor Michael Chapman told The Sunday Telegraph that donor shortages had become critical, falling from 100 to 10 at his clinic in the past four years.

"Last year we only had two or three donors on our books," Professor Chapman said. "Today around Australia there are about 50 donors, but the demand is still substantially higher than that."

As a result, IVF Australia started importing sperm from the US two months ago.

Professor Chapman said donor imports were "not ideal" but would help reduce waiting times for insemination.

In January last year a law came into effect stating that all sperm donors must agree to provide identifying information so that the child would be able to contact them once they reached 18.

Fertility specialist Professor Peter Illingworth said the change in the law was directly linked to the drop-off in sperm donors.

"There is no doubt that when the law was first introduced, it affected the number of men willing to donate sperm. It is a big undertaking. Being a donor is very serious and the fact is, not many men are willing to do it," he said.

Professor Illingworth said the clinic has been careful in its choice of an offshore sperm bank.

"We have for a long time been looking for a way to improve sperm donor numbers in Australia.

"We have now found an agency in the US whose donors have given consent to provide identity to the child after they turn 18," he said.

Professor Illingworth said sperm donors would also stick to strict NSW regulations stipulating that each donor could only supply four families with sperm.

Professor Chapman said Australian clinics needed more local donors because importing sperm was "not ideal".

"There is still that issue that, despite their undertakings, an overseas donor perhaps is less likely to be tracked in the future," he said.

At Genea fertility clinic, doctors do not source sperm, instead recommending finding a "known donor" so the biological father is not a stranger to the child.

"Genea strongly supports the rights of children to know their genetic heritage and will only provide treatment in situations where this is the intention," Genea medical director, Professor Mark Bowman, said.

"In practice, this requires that recipients recruit their own donors and together go through a process of implications counselling."

In the 12 months to September, 194 babies were born in NSW through sperm donations.