A few months before her 40th birthday Emma* decided to freeze her eggs.

The Melbourne professional had heard about the procedure in the media, but didn’t consider doing it herself until she reached her mid-30s with no partner in sight.

“I felt like my time was potentially running out to have a child if I wanted one, but I wasn’t sure if I wanted one,” she told Mamamia. 

“I wanted to give myself the best chance of having one if I did have a partner in the future – or if wanted to have one by myself in the future.”

Emma fits the mould of the many single, healthy Australian women in their 30s, now preserving their fertility though egg-freezing.

For her it was a practical decision; for others it’s an emotional one.

Regardless, when successful, it is a straight-forward insurance policy against the ticking clock.

"As women we kind of get our choice taken away by our biology, and there’s nothing we can do. So it’s empowering to do something about it," Emma said.

"It’s kind of like one more thing I don’t have to worry about any more."

Over two attempts in October 2015 and February 2016, Emma managed to retrieve 33 eggs (around 10 are needed for a round of IVF).

She had minimal side-effects, although she did suffer from ovarian hyperstimulation syndrome, a potentially serious condition that causes the abdomen to swell up.

Luckily, it passed in a few days, and in short: the process was a complete success.

"If people could have the run that I had, I would say 100% do it — but everyone’s experience will be different," she said.

"It’s easy to be positive when things turn out well. I know people who have undergone the procedure and have not managed to get eggs.

"So they’re in the same position as before but have $10,000 less in their bank account. That would be harder to deal with I think."

Dr Karin Hammarberg from the Jean Hailes Research Unit at Monash University told Mamamia the prohibitive cost of the procedure - not to mention potential for it to fail - is what puts many women off.

Aside from the cost of retrieving the eggs, you also have to pay to store them, as well as forking out for IVF.

"It's more than just putting eggs in the freezer. If you don't use them you've wasted your money, and if you do use them there's additional cost," Dr Hammarberg said.

"You need at least 10 to have a reasonable chance to have a baby. Only the less likely you are to produce that number in one hit, so that would then be $20,000 or $30,000. None of this is refundable."

So, what exactly is involved?

The first step is speaking to your GP, who will refer you on to a fertility specialist at a clinic, like Melbourne IVF, which is where Emma went.

Before going ahead, you will also be invited to speak with a counsellor.

Then, a course of fertility drugs is administered - via self-injection - to develop the egg-containing follicles in your ovaries.

The mature eggs are retrieved in an ultrasound guided procedure, under a light anaesthetic. In terms of down-time, Emma said she went back to work the next day.

How long can the eggs be stored?

In theory, eggs frozen in liquid nitrogen can be stored indefinitely, but there is a 10 year time limit in Victoria, which can be extended if need be. (Post continues after gallery.)

Who does it?

A recent study from the Jean Hailes Research Unit interviewed 100 Victorian women who froze their eggs at Melbourne IVF between 1999 and 2014.

Most were single, university educated professionals and nearly half were over the age of 38.

Despite what the stereotype would have you believe, most weren't delaying childbirth for their careers — they were just waiting on a partner ready for fatherhood.

What's the cost?

In Australia, the cost of egg freezing is around $10,000 per round and is not subsidised by government or private health insurance.

Is it worth it?

Well that depends. Only a fraction of the women surveyed had actually used their frozen eggs - around six per cent.

While one in five of the women were pregnant or had given birth, more than half of the 21 pregnancies came from spontaneous conception and more than a quarter from IVF using "fresh" eggs.

"I think we'll find in the end there are a lot of eggs in storage that women are not going to use. Time will tell," Dr Hammarberg said.

Even Emma admitted if she doesn't meet anyone, she may not use the eggs.

She is just happy to know they're there.

"At least you know you’ve tried everything you could possibly try," she said.

"I think it’s one of the best things I’ve done."

You find out more about egg-freezing through the Victorian Assisted Reproductive Treatment Authority.

*Not her real name.