Reproductive specialists say attracting enough men to satisfy demand has always been difficult, and waiting lists are longer because of the growing number of childhood cancer survivors rendered infertile by treatment. The dwindling stocks are also sought by single women and same-sex couples.
The director of the hospital's department of reproductive medicine, Stephen Steigrad, said at least 20 men who had undergone aggressive cancer treatments requested donor insemination for their partners every year. Without new donors, the service would have to be stopped within six months.
The Centre for Cancer and Blood Disorders at Sydney Children's Hospital at Randwick says one in 900 Australians aged between 16 and 45 has survived childhood cancer.
Changes to NSW legislation this month requiring donors to register their names on a mandatory central register had turned potential donors off, said Professor Michael Chapman, from IVF Australia, which has a waiting list of two years.
The Assisted Reproductive Technology Bill guarantees children access to their father's name, date of birth, education and medical information once they turn 18. It may also require details of the donor's partner and other children to be listed.
"Previously men could donate knowing there was no way they were going to get a knock on their door," Professor Chapman said. "Now men are less likely to donate."
Dr Anne Clark, from Fertility First Hurstville, said the sperm shortage would be compounded by the new laws, which legislate that one man's sperm can go to only five families, down from 10.