As the number of women freezing their eggs and embryos in Australia surges, some fertility clinics are struggling to keep up with freezer storage demands.
William Ledger, an emeritus professor of Obstetrics and Gynaecology at the University of New South Wales, says he has heard of "times where clinics have not been able to keep up with demand, and [there have been] people not starting [IVF] cycles because there's not the storage space available".
Genea Fertility, one of the largest groups of IVF clinics in Australia, is considering an expansion in the future.
A spokesperson recently told the ABC that the fertility industry has witnessed substantial growth in egg freezing, which posed challenges for managing storage.
For example, in 2013, Genea had 53 patients who had 674 oocytes (developing eggs) in storage. In 2023, that had increased to 38 times more patients, with 34 times more oocytes in storage.
"We are seeing quite a significant increase in patients and, obviously, an increase in the number of eggs. And, as it stands at the moment, of those people that have stored eggs, 80 per cent [of eggs] actually remain in storage," says Dr Anthony Marren, a Sydney-based fertility specialist who works with Genea.
Dr Molly Johnston, a research fellow at the Monash Bioethics Centre at Monash University, has also heard about clinics dealing with this problem.
"Anecdotally, I am told that cryo-storage is now becoming an issue for clinics. So I know of clinics that have expanded their storage facilities and have plans for further extensions so that they are prepared for what they are anticipating to be even greater demand for storage in years to come," she says.
"So this does seem to be a growing issue."
Storage isn't limitless
This surge in demand shouldn't really be a surprise for the IVF industry.
Dr Johnston has been studying the rates of egg freezing between 2011 and 2021.
She says the number of egg-freezing cycles carried out in Australia and New Zealand rose by more than 1,500 per cent in that time. Although the data is limited, she believes increased patient numbers were driving the increase in cycles.
"What we do know is that the number of eggs that have been placed in storage is rapidly outpacing the number that are removed," she says.
"[However] storage isn't limitless, so there will come a time where this could become a problem for a lot more clinics."
The process of egg freezing has advanced dramatically in recent years, but it is not without its hurdles.
Typically the process involves a fortnight of gonadotropin injections, followed by egg collection. The number of eggs collected depends on the ovarian reserves, but 10 to 15 oocytes or developing eggs provide reasonable potential for future fertility. Twenty is optimal.
These eggs are then frozen in liquid nitrogen, although this type of storage is expensive and the containers take up a lot of space.
Those who choose to freeze their eggs do so for a variety of reasons.
Professor Ledger has previously worked at the Royal Hospital for Women in Sydney in a statewide onco-fertility program. This involves freezing eggs for very young women before they start chemotherapy. He believes many want to store their eggs for longer than a decade.
In general, egg freezing is also done as part of an ongoing IVF process or because patients want to postpone pregnancy to pursue career aspirations.
And one of the most common reasons for egg freezing is that those who do so are single and want to preserve their fertility for the future.
But are Australians relying too much on this?
"I don't necessarily think they are relying on it as an option," Dr Johnston says.
"To do so would mean that people are seeing this as their first plan for reproduction … however, that is not what the data tells us.
"The data tells us that most people freeze their eggs as a backup plan.
"We also know that very few people returned to use them in storage. And one of the most common reasons for why they don't return is because they can [conceive] without [IVF] assistance."
It's reported that only 10 per cent of women return to use their frozen eggs.
It should also be noted that freezing eggs doesn't guarantee a successful pregnancy for various reasons including that eggs do not always survive the thawing process.
A UK study studied 129 women who returned to use their eggs over a 10-year period, and found that only 21 per cent succeeded in having a baby.
Indeed, Dr Johnston discourages women from seeing egg freezing as "an insurance policy".
"Just because you have eggs in storage that doesn't mean that those eggs will [be fertilised], create embryos and lead to pregnancies and live births," she explains.
She says success rates often come down to how old a woman is when she freezes her eggs — a woman's fertility declines in her late 30s and 40s — and the number of eggs they have frozen.
"If having children is really important [to you], the only true test of fertility is to try and conceive," she says.
"So freezing eggs, you might be able to collect quite a few. That doesn't tell us anything about the potential to lead to a live birth."
How long to store eggs?
The length of time Australians can store eggs and embryos varies across the states, but on average, it is around 10 to 15 years.
This differs greatly from the United Kingdom, where the laws were changed in 2022.
Initially those living in the UK could only store their embryos for up to 10 years, but that has been extended to 55 years.
Professor Ledger can see the benefit of changing the laws in Australia, particularly for young women who have undergone chemotherapy.
"We already know from basic human biology that eggs or embryos stored in liquid nitrogen don't deteriorate over many years," he says.
"So there's no medical reason to discard them. It's more of a political process. The rules were set up when IVF was young. Nobody quite saw what was coming as the science has moved along so quickly. And so sometimes it's just a matter of state legislatures keeping up with change in medical practice."
But while changes to laws around storage times could benefit patients, fertility expert Dr Marren says increased time in storage could mean increased risks for private clinics.
"If you have someone who freezes eggs as a teenager, because they're going to be exposed to chemotherapy, for instance, then there'd be no reason … that by the 15 years [in NSW] doesn't get it extended," he says.
"But I think having a blanket rule of 55 [years] does mean that … clinics are going to be in a situation where there's going to be this excess numbers of eggs, sperm, and embryos in storage."
And if that happens, the need for storage will only continue to increase.
"People tend to keep eggs, embryos, and frozen sperm for many years. It's a hard thing to sign a piece of paper to dispose of your embryo. People see them as a potential human life," Professor Ledger says
"It's a tough thing to say, 'No, we don't want these anymore'.
"People can donate to another couple if we have embryos, but not everyone is comfortable with another couple having a child with their DNA."
Professor Deirdre Zander-Fox is a chief scientific officer at Monash IVF Group in Victoria. She says extending storage times needs to be carefully considered.
And she can see both sides to the argument.
"The question is do women have enough time to use their materials when they're ready. You don't want to cause patients stress," she says.
Particularly if women have frozen their eggs when they were young, she adds.
But equally extending time limits up to 55 years like in the UK could create further issues like the ongoing costs of storage.
"So there's a delicate balance here … where we don't end up with huge amounts of material and not being able to locate owners and get them to make decisions," she says.
Where to store them?
As demand increases, clinics are contemplating finding bigger storage spaces, which Professor Ledger says can be tricky.
This is because some of the biggest storage tanks can now be as big as three metres wide by three metres tall.
In South Korea, some enormous cryo-banks can take up as much space as a football pitch.
"You [also] have to have very good ventilation. There was a lab technician who suffocated and died because [the tank] was stored in a small room that wasn't properly ventilated," he adds.
Dr Marren says Genea are also thinking about where they could store eggs, embryos and sperm in the future.
He says the majority of liquid nitrogen tanks they have in Sydney are located right next to their laboratories, but as these tanks fill up they may have to be stored at other sites.
And so, as the industry expands and demand grows, more clinics and providers will need to solve this problem.
"I've been in IVF for 20 years this year, and certainly when I started, we had canisters that rolled under benches in labs," Professor Zander-Fox says.
"And even when I first started, storage problems weren't really a thing, and I've seen it change over time.
"A new clinic now has a whole cryo room. It's a very important room. You're often saying we'd like it a bit bigger please."
And so as the industry continues to evolve, even more space will be required.
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