A controversial medical development is allowing cancer patients to keep alive their hopes of having a family.
The procedure goes well beyond just freezing eggs and sperm – doctors can now remove and freeze parts of an ovary, then later transplant them back into the body.
Any woman, or even a young girl, who suffers cancer and survives can then go on to have babies.
But it's still considered controversial, and in New Zealand the procedure is yet to be fully approved.
Shylo Harrison is a professional child carer and cancer survivor from Northland's Mangawhai.
For the past three years she's been a nanny for Kara, Taryn and Brayden. But before she turned her attention to a career in childcare, Ms Harrison endured the unthinkable at the age of just 17, when doctors found she had a brain tumour.
"They were pretty sure it was benign, and then two weeks later when we got the biopsy results they told me I had stage-four cancer and I had to start treatment. My hair was going to fall out, which was the worst thing for me. I bawled my eyes out when I found out my hair would fall out."
The golf-ball-sized tumour in her head was immediately removed, but, like in many cancer cases, the chemotherapy and radiation to come would likely kill off all her eggs, leaving her infertile. Even though the idea of freezing ovarian tissue was so new, they suggested Ms Harrison do it.
"I knew it was all really experimental and I didn't know if I could have a child anyway," she says. "But if there was a chance then I definitely wanted to take that chance and have the surgery because one day I would want to have children because I love kids."
Ever since then, her ovarian tissue has been locked inside a frosty tank of liquid nitrogen, along with the tissue of 45 other Kiwi women and girls.
Surprisingly it's children who stand to benefit most from such advances. Fertility Associates director Dr Mary Birdsall believes cancer treatment should be about more than just saving lives.
"It's not just about surviving; it's about these children surviving and doing all the things that are associated with being adults, and part of that is having babies," says Dr Birdsall.
Melbourne twins Kaia and Alexis and their parents, Vali and Dean, are living proof that it works. As a 19-year-old, Vali contracted a rare, slow-growing cancer. The tumour appeared in her left ovary, which had to be removed.
Years later when the cancer spread throughout her abdomen, her doctor said her remaining ovary would need to go too. Only this time, part of it was frozen.
The doctor doing the work on tissue preservation was Associate Professor Kate Stern – Australia's leading fertility expert.
"From a scientific point of view it can remain here for a very long time," says Assoc Prof Stern. "There's no evidence that you get any decay over a long time. It's frozen in a snapshot in time."
That means the slithers of an ovary could still be functional a decade later, or potentially even longer. When the time comes to use the tissue again, all it takes is a relatively simple laparoscopic operation.
"It usually takes four months for the tissue to start working because it needs a new blood supply," says Assoc Prof Stern. "But it is amazing. It almost always starts to work and produce hormones within four to five months of being grafted. Then we might try IVF or patient might try to get pregnant themselves."
In a world first it worked in Vali's case. After three years and 17 cycles of IVF they went in for a scan to find out it was twins.
That perfect result is just what Ms Harrison might one day hope for. But while removing and freezing tissue is allowed in New Zealand, the operation to put it back into patients isn't.
Forty-eight babies have been born around the world as a result of ovarian tissue being grafted back into patients. However, it's not happening here.
In New Zealand, young girls and women facing cancer treatment are having their ovaries frozen and stored. But the operation isn't considered what's known as an "established procedure" and it doesn't have full Ethics Committee approval. So while patients can get tissue removed and frozen here, they're actually not allowed to get it put back in. They'd have to go to Australia for that. And that's something Ms Harrison can't quite fathom.
"My partner and I would love to have a child one day," says Ms Harrison. "Even with the surgery I might not even be able to have it at the moment, which is crazy to think. I don't think it's fair at all that we wouldn't be able to. It doesn't make sense to me."
The committee that makes policy and ethics decisions is getting there. But it's an inherently arduous process, which requires the drafting of rules and then sign-off by the minister.
"I think it needs to be a thoughtful process and there are risks," says Dr Birdsall. "The risks are that there may possibly be cancer cells in this ovarian tissue."
It's possible a patient who has finally become cancer-free could in fact get their old cancerous tissue put back in. Perhaps unsurprisingly, they're already working on ways to get around this.
One possible option being investigated according to specialists in Melbourne is to use an animal like a rat to be the host of human tissue.
"There is an idea we have about the future where we could graft the tissue into non-animal models or even other animals and then extract the eggs and put the embryo back in the patient," says Assoc Prof Stern. "That would reduce the risk of cancer going forming back in the body.
"I think with any new technology the science always goes ahead of the moral and ethical discussion, because you need to have the technology and then you have the discussion."
In New Zealand, it's not just ethics getting in the way; it's money. The Government will pay for the freezing of eggs and sperm, but not ovarian tissue. Ms Harrison is paying $620 every year to keep her tissue on ice in Auckland and the surgery costs thousands.
"I am lucky I have so much support," she says. "But if I didn't I would not have been able to do any of this on my own."
Oncologist Scott MacFarlane is the clinical head of child cancer. He wants it funded, but says as it stands the science is still too experimental.
"I think it is promising but the evidence is not complete," says Dr MacFarlane. "It's certainly not complete enough to take money away from another established programme to fund this programme."
So in New Zealand we have to wait, which is fine if you have time. But Ms Harrison wants to start trying to have children within the next year. She just hopes those considering the situation make the right decision and soon.
"I just go for MRIs every year just to make sure it hasn't come back," says Ms Harrison. "So far so good. Hopefully it stays that way, so hopefully one day I'll be able to start a little family myself if I'm lucky. Well, if the Government helps me."