Warning on trend to freeze eggs

A Perth fertility expert has cautioned women about "social freezing" their eggs to delay having children, arguing it could lead to "orphaned" eggs or encourage more higher-risk pregnancies in women aged over 40.

University of WA professor of reproductive medicine Roger Hart said women in their late 30s might also need to have three cycles of in-vitro fertilisation and reserve as many as 30 eggs to reasonably guarantee a baby.

He has warned of the downside of freezing eggs to preserve fertility, after Australia's biggest IVF company Virtus Health revealed it was following the lead of US technology giants Apple and Facebook in subsidising the procedure for female staff.

It costs about $10,000 for egg freezing and another $300 a year to store them.

Professor Hart, medical director of the Fertility Specialists of WA, said he wanted to temper some of the enthusiasm for freezing eggs for non-medical reasons.

"The prospect of preserving fertility is a fantastic opportunity and no doubt many women will ultimately be very grateful they had the foresight to undergo the IVF process and freeze their eggs so they had a child later in life," he said.

"But the age the woman embarks on the egg freezing is crucial, as egg quality rapidly deteriorates in the late 30s, so a woman embarking on egg freezing in her early 30s will only need on average about 12 eggs to effectively guarantee a child in later life.

"If she leaves this to her late 30s, she will need in excess of 30 eggs to provide the same degree of reassurance, which may mean that she would need up to three IVF cycles."

Professor Hart said unlike women with a medical reason such as breast cancer who wanted to preserve their fertility before chemotherapy, those who chose "social freezing" did not get a Medicare rebate.

Women should discuss egg freezing with a GP or fertility expert, he said.