In preparation for the day when you hit pause on your frenetic schedule of work-barre-frosé-repeat to start thinking about your fertility, it's time we had a talk. Thanks to a cocktail of social circumstances (marrying later, a dire lack of eligible men, career ambitions, travel opportunities...), women are putting off having babies, which is fine - unless the ticking of your biological clock is keeping you up at night.

Enter egg freezing: the closest thing we have to a fertility insurance policy. "The success rate of egg freezing has improved enormously in the last 10 years," says Associate Professor Peter Illingworth, Medical Director of IVF Australia. "Now it's a very realistic prospect for having a child." Realistic, but not absolute. "It's an insurance policy that has no guarantees of paying off," warns Dr Simone Campbell, fertility specialist and gynaecologist with City Fertility Centre. Here's what you need to know.

What is egg freezing?
In basic terms, egg freezing offers the chance to cheat your biological clock by extracting and storing unfertilised eggs, giving you the potential to conceive once you're ready for a baby. The eggs are snap frozen under a relatively new process called vitrification. "In the past ice crystals used to form, but now we use this snap freezing technology the eggs have a good thawing rate," says Dr Campbell. "We expect about 80-85% of the eggs to thaw after they're frozen, and once they're thawed they act like a fresh egg."

Putting off having children? You NEED to read this

Who's eligible?
The experts agree: between 30 and 35 is your window for putting eggs on ice. The younger you are, the better quality your eggs - but that doesn't mean anyone's advocating for 21-year-olds to hit the freezer. "The younger someone does it, the less likely they are to use the eggs," says A/Prof. Illingworth. "It's just too early to say what will happen in your life."

But the longer you wait, the less likely your chances of a successful pregnancy. "Once someone's got to their 38th birthday, the likelihood that the eggs will help them becomes so small that I would not advise it," cautions A/Prof. Illingworth. In other words, it could be time to get cracking.

What's involved?
Usually, 10-12 days of hormonal stimulation via self-administered injections to boost your egg count (so harvesting eggs doesn't reduce your existing egg supply) before the eggs are collected under anesthetic.  

Is it safe?
"Generally it's a straightforward procedure and it's very uncommon to have complications," says Dr Campbell. "But if you're doing this electively, then you need to make sure you're fully aware of the potential risks." The worst case scenario is ovarian torsion, in which the enlarged ovaries get twisted and cut off blood supply, requiring emergency surgery. "That's a really rare complication," says Dr Campbell. Usually, women simply take the day of and day after their procedure off work.

As for any risks to babies born from frozen eggs? "As far as we can see, the children born from frozen eggs are as healthy as any others," says A/Prof. Illingworth. "However, only a relatively small number of babies have been born that way, and small levels of risk would not be able to be detected on the number of babies that have been born thus far."

Putting off having children? You NEED to read this

Is it expensive?
Yes. In Australia, Medicare only subsidises egg freezing for medical reasons, rather than what's officially known as 'social egg freezing.' At IVF Australia, the egg freezing cycle (including blood tests, scans, medications, surgeon's fees and the freezing process) costs $9,995, with an additional $1015 for day surgery and $500/year for ongoing storage.

What's the success rate?
"The general feeling is that about 20 eggs in the freezer will give you a 50% chance of a take home baby in future," says Dr Campbell. For a number of reasons, hard stats are hard to come by. "One of the difficulties is that although in Australia a significant number of eggs have been frozen, not many of those eggs have been thawed," says A/Prof. Illingworth. Another issue is there's no way of knowing if the eggs you've frozen are viable or not.

Both Dr Campbell and A/Prof. Illingworth stress that egg freezing should be considered a back-up option only: "Don't let the fact you've frozen eggs put you off trying to have a family naturally if you're in a position to do so," A/Prof. Illingworth says. "A heightened perception of success rate is the biggest egg freezing misconception of all."

Next steps
First stop is your GP, who can refer you to a fertility specialist. You'll also most likely need an AMH - a blood test that indicates your ovarian reserve. "Ovarian reserve is going to help us have some expectation of what numbers of eggs to expect," says Dr Campbell. "But importantly, it's not an indicator of the chances of pregnancy - if your reserve is less than you thought but you're 32, you've got a 32-year-old's chance of having a baby, which is still a very high chance." 

Putting off having children? You NEED to read this