Egg freezing. Is it worth it?

Pregnancy 101
Oct 26, 2023

Woman thinking over a cup of tea

Egg freezing has become big business in Australia. Women are seeing more and more targeted ads by fertility clinics encouraging them to put their eggs on ice. And the marketing is working. The number of women who froze their eggs tripled in the five years from 2015 to 2020 (data from the National Perinatal Epidemiology and Statistics Unit). Is the surge due to fear mongering or fact based? Let's delve into the nitty-gritty.

What is the success rate of egg freezing? 

Let's assume that 'success' is the likelihood of a successful live birth down the track. We'll break down the process and associated statistics below:

STEP 1: Stimulate the Ovaries & Monitor Follicle Growth

What's involved? Women inject themselves with fertility hormones (1 - 2 small needles a day in the belly depending on the dose the specialist gives). This is done every day for 8 - 14 days. 

During this time, ultrasounds are done to monitor how the ovaries and follicles are doing (warning ladies this is an internal ultrasound so the camera goes up the HooHa). You also need blood tests to monitor hormone levels. Lots of jabs. Fun. 

Statistics: Women on these fertility hormones can grow anywhere between a few to 20 follicles with eggs inside. Think of follicles like the little houses that the eggs live inside. Not all follicles grow to the desired size, and not all follicles have eggs that are good to use either. There's no guarantee to the number of viable eggs you're going to have until you go into surgery but on average specialists aim for 10-15 good ones. 

 

STEP 2: The Trigger Shot & Egg Retrieval Surgery 

Once your specialist is happy with the size and number of follicles, there's one final needle to trigger ovulation (hCG). This is carefully timed with the retrieval surgery. The risk in administering the trigger injection too early is that you'll lose all the eggs you've been lovingly growing over the past couple of weeks. The risk in triggering too late is that the eggs won't be in the right spot for collection during the surgery. So, whatever time the specialist says to administer the 'trigger shot' is THE exact right time to do it at. No matter what time of day or night. It's typically 36 hours before surgery is scheduled.

The surgical procedure to get the eggs out is usually done under light sedation or anaesthesia. A thin needle goes up through the vagina into the ovaries using ultrasound guidance. The eggs are then sucked from the follicles. Cute. The procedure typically takes 20 - 30 minutes and you're out like a light (thanks anaesthesia) for it so there's no pain. A bit of soreness and swelling is typically expected but after 2-3 days post surgery, most women feel like they can resume normal activities. 

Statistics: The aim here is to get enough mature eggs to increase the chances of a successful IVF cycle later on. The exact number of eggs retrieved varies, ranging from a few eggs to more than 20 or even higher in some cases. However, not all eggs are 'mature' or 'viable'. Out of the total number of eggs retrieved, expect only 70 - 90% to be mature eggs that are viable for freezing / IVF. So, if you get x15 eggs out of a cycle then it's likely only 10 - 13 will be 'mature' and usable. If you get x8 eggs out of a cycle then it's likely only 5 - 6 will be mature and good to use / freeze. 

egg collection gif

STEP 3: Freeze or Fertilise Eggs with Sperm 

Once the viable eggs have been collected, the next step is to either stop the process here and pop the eggs on ice for later fertilisation. Or, if you prefer to freeze an embryo (egg + sperm), then the clinic will go to the next step of fertilisation. This happens through two main methods: traditional insemination or intracytoplasmic sperm injection (ICSI).

  • Traditional Insemination: In this method, the retrieved eggs are combined with a sample of sperm (a whole bunch of them) in a culture dish. The sperm naturally attempts to penetrate the eggs, and fertilisation occurs if that's successful.

  • ICSI: In cases where there are concerns about sperm quality or if previous fertilisation attempts have been unsuccessful, a single healthy sperm is directly injected into each mature egg using a specialised micromanipulation technique.

Statistics: Approx. 60-80% of mature eggs fertilise with sperm. For example, if you extracted 10 mature eggs, you can expect about 6 - 8 eggs to successfully fertilise. The fertility clinic typically takes 16 - 24 hours to let you know how many eggs have successfully fertilised.  

Side note. If you decide to freeze mature eggs before fertilising them (because there's no confirmed sperm in the picture right now) then remember that freezing and unfreezing doesn't come without its risks. According to various studies and reports, the survival rates for frozen mature eggs typically sits at 90% to 95%. This means that a significant majority of eggs that are vitrified (frozen) have a high chance of surviving the thawing process, however, it's not 100%. For example, it might be wise to plan for an egg to drop off if you are freezing 10. 

 

STEP 4: Embryo / Blastocyst Growth 

Once you have fresh fertilised eggs (egg + sperm); the fertilised eggs are popped away in a safe place to do their thing for the next 3-5 days. During this time the fertilised egg should undergo cell division and growth into a little embryo. The embryologist observes its development to select the healthiest and most viable embryo for transfer. The blastocysts or embryos are usually graded by the fertility clinic and only the strongest ones are suitable for transfer. The transfer can happen 3-5 days after egg collection (fresh cycle) or the embryos can be frozen to use at a later date. Again, freezing and unfreezing can have a slight drop off however it's less than when freezing just the eggs. Here, statistics show that 95-98% of frozen blastocysts survive the freezing and thawing phase. 

Statistics: Approx. 40-60% of fertilised eggs will progress to the blastocyst stage. Some may stop developing early on, whereas others may develop more slowly. The ones that do reach the blastocyst stage (approx. 5 days after fertilisation) are often considered to have a higher chance of successful implantation. Therefore, if you started with a total of 15 collected eggs, 10 of which were mature eggs that could be fertilised, 7 of which successfully fertilised (based on 70% average statistic), then you should only expect 3 or 4 successful blastocysts from that process. 

 

STEP 5: Embryo Transfer

After all the needles, surgery, and angst of watching a little embryo develop into a healthy blastocyst the actual embryo transfer then has a 20-50% success rate of implanting. The transfer is similar to a pap smear in sensation, the specialist transfers the previous blastocyst cargo into a catheter and then up through the cervix into the uterus. The procedure is guided by an ultrasound that requires women to have a full bladder for the procedure.

After the embryo has been transferred, you're free to use the bathroom and go about your normal activities. The next touch point will be a blood test or pregnancy test a couple of weeks down the track. This is where your doctor will be able to confirm (thanks to hormones in the blood) whether the little blastocyst has successfully buried itself into the uterus lining meaning a successful pregnancy! OOF what a journey. 

Statistics: Approx. 20-50% of transferred blastocysts successfully implant. 

 summary of freezing eggs

Summary

So to sum up, let's look at an average case scenario that looks at the whole picture of egg freezing statistics:

- Let's assume your body responds well to the hormone treatment and surgery so you get x15 eggs out of an IVF cycle

- Out of those 15, it's likely only 10-13 will be 'mature' and usable to freeze and/or fertilise

- Out of those 10-13 'mature' eggs, it's likely to get approx. 6 - 9 eggs that will successfully fertilise with sperm. There's a slight drop off (5 - 10%) if you are thawing out mature, unfertilised eggs you've had frozen 

- Out of the 6 - 9 fertilised eggs, it's likely only 3 - 5 will make it to the blastocyst phase 

- Out of the 3-5 healthy blastocysts (assuming they're all suitable for transfer), only 1 - 2 will most likely implant into the uterus and give that long awaited successful pregnancy outcome  

What is the ideal age to freeze eggs?

While it's tricky to strike the perfect balance between youth and fertility preservation the science is pretty clear. The younger the woman (under 35), the more likely egg collection will bring good results. More than age, the health and wellness of the woman is important too. A healthy diet and lifestyle goes a long way for fertility and egg freezing.

What are the risks and side effects of egg freezing?

Egg freezing is generally considered safe, but it's important to keep in mind that, like any medical procedure, it has its share of potential risks and side effects. The main concerns include the risk of ovarian hyperstimulation syndrome (OHSS) when high doses of fertility medications are used to boost egg production, and there is a rare possibility of infection or bleeding during the egg retrieval process. Some common side effects after egg retrieval are bloating, discomfort, and mild post-retrieval pain. Before any medical procedure it's a good idea to speak to a fertility specialist and weigh the pros and cons to make sure you're making an informed decision that's right for you.

How much does egg freezing cost in Australia? 

Ah, the financial aspect—a question that weighs on the minds (and wallets) of many. The cost of egg freezing in Australia varies widely depending on several factors, including the location of the fertility clinic, the specific services included in the package, and any additional expenses related to medications, storage, and monitoring. However, the approximate range to budget for is 7,000 AUD to 10, 000 per cycle. This cost usually covers the initial consultation, ovarian stimulation medications, egg retrieval, laboratory fees, and the first year of storage (which is then approx. $500 per year). Some people may need multiple cycles for a sufficient number of eggs, which would therefore add to the price tag! 

Can I still get pregnant naturally after freezing my eggs? 

It's a valid concern. Many women wonder if freezing their eggs will affect their chances of conceiving the old-fashioned way down the road. The answer is yes. Egg freezing is a fertility preservation technique, it does not impact your natural fertility or ability to conceive naturally down the road if you so chose. The question here is what 'down the road looks like'. If it's too far 'down the road' when you're significantly older and/or have other health concerns then conceiving naturally or having a successful ivf procedure can become trickier. 

What is the ideal age to freeze your eggs? 

According to fertility specialist, Dr Natalie Crawford, the ideal age for egg freezing is 32/33 - because the average person will still have a peak number or eggs and good egg quality. But in her clinic, she has had much much older women freeze their eggs and have a baby (even over age 40), but the older you are, the more women need to be prepared that it may take many cycles. Since we can’t change our age, increasing the number of eggs is the best thing we can do.

Are you thinking about freezing your eggs? 

Deciding whether or not you want to freeze your eggs is a deeply personal decision. Whether you’re concerned about your fertility declining, want to hold off on children while you pursue your career or simply want to have a backup plan for whatever reason, the decision is yours and yours alone. If you’re looking into freezing your eggs out of fear of your fertility declining, the good news is that there are natural ways to boost your fertility. We have a wide range of fertility teas available designed to help with your conception journey. Through the use of powerful herbs, our tea for conception has been artfully crafted to support your fertility journey. Browse our range to find out more.