New Zealand is struggling to find sperm donors amid concerns there is only enough to treat approximately 80 families.

Due to increasing demand and recent legislation putting off prospective donors, women can wait up to two years for sperm.

Since 2004, legislation requires donors to agree to being identified to any child when they turn 18.

In addition to banning anonymous donations, it also prevents donors from receiving any payment for their services.

Dr Mary Birdsall, a fertility specialist with Fertility Associates, told the Guardian: "Increasingly we are hearing of New Zealand women travelling overseas for reproductive tourism.

"It’s a very challenging situation. It’s challenging to recruit donors, and it is tough on the women who are psychologically and biologically ready to start a family, but can’t."

The number of same-sex and single women applying for sperm has cause a rise contributing to the depth of the shortage.

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Dr John Peek, general manager of Fertility Associates said: "New Zealand has had a shortage of sperm donors for a long time.