Maria Cleve's is particularly poignant, with her quest to conceive running alongside the one to keep her husband alive.

Tim Cleve was diagnosed with brain cancer at the age of 23, and though he was not then in a relationship he stored some sperm in case the chemotherapy made him sterile.

Three years later he fell in love with Maria, who lived near him in the town of Kilmore, an hour north of Melbourne, and two years into their marriage they began the process of IVF.

No sooner had they begun the first stage, which involves stimulating the ovaries to produce eggs, than they hit their first hurdle.

The process involves self-injecting into the stomach for seven days, which clinics hope will retrieve about five eggs.

In Mrs Cleve's case, the drugs overstimulated her ovaries and she produced 34 eggs, leaving her in severe pain and forcing several trips to hospital for pain relief over the next few days.

As she lay on her sick bed, the clinic rang with stressful news.

Only one of the eggs survived.

They had managed to fertilise it to produce an embryo, but it was not strong enough to be frozen, and she would need to come to the hospital immediately for it to be implanted.

A day later, the clinic rang again. The embryo had become stronger. It would survive.

''We were just amazed because we thought it was such a lot to go through for absolutely nothing,'' Mrs Cleve said.

''I can't explain how happy we were. That was Ned.''

That was Mrs Cleve's happy ending, but it was not the only ending. As the pregnancy progressed, so too did Mr Cleve's brain tumour. Their only hope was to raise $60,000 for the brain surgeon Charlie Teo to operate, but that would only buy Mr Cleve 12 months, in the hopes medicine would advance faster than the tumour.

The money was raised and the operation was done. Mr Cleve lived long enough to cradle his son. Four months later he died.

Mrs Cleve would like to use the frozen sperm to conceive a sibling for him, but another mountain has risen in her path.

The couple signed documents agreeing that neither of them would conceive using the other's gametes in the event that one of them died. ''At the time, the reasoning was we tried to live with the attitude that he was going to get better, even though we knew he wasn't,'' Mrs Cleve said.

Her only option is to convince a clinic in the ACT or Queensland, which is bound by ethical rather than legal guidelines in relation to embryo use, to do the treatment.

Then she needs to persuade the Victorian Assisted Reproductive Treatment Authority to transfer the sperm to that clinic.

''I know Tim would want me to have another baby,'' she said.