January 24, 2024
8 Minutes

Freezing eggs vs Freezing embryos: Whats the difference?

Freezing eggs vs Freezing embryos: Whats the difference?
Written by
Navya Muralidhar
|
MSc Clinical Embryology & Embryologist

In an eggshell...

  1. Freezing eggs is a method to preserve your fertility, for your particular page. On the other hand, freezing embryos requires sperm, and in a way, freezes your possible future offspring
  2. The cycle lengths, medications used, and procedure differ- for freezing eggs and embryos
  3. The decision to either freeze eggs or embryos- is ultimately down to you, your health and personal preference!

Suppose you've scoured the internet for any terms related to fertility preservation, or procedure. In that case, you may have come across the two most common ones: egg freezing and the other, embryo freezing. 

And if you've wondered: Hmm, that does sound a little similar.. you're not the first.

One of the methods is a way to preserve your fertility. Imagine you're in your 20s and you have the capability to preserve your genetics and your fertility during that particular age. 

And the other method is a way to preserve your future offspring but in the form of small, living cells, frozen away until use. But if you're wondering- which one is right for you, and which procedure you should go for, this article is for you.

Read on to find out! 

Preserving fertility: eggs or embryos?

Here's a small, simple breakdown of the two processes, before we get down to their differences.

Egg freezing to preserve fertility

This is a common procedure, done for various medical and personal reasons, known as social or elective egg freezing 1. The entire idea here is to preserve fertility at younger ages when your genetics is also at its best!

That is because as we age, the genetics behind our fertility, and ability to conceive becomes a little more complex.

So how does egg freezing work?

In egg freezing, you will be put on a medicated cycle solely to ensure more eggs grow in that cycle. Then the growth and development are monitored, until the egg retrieval day.

On the egg retrieval day is when you’ll be under anaesthesia and the doctors get to work. With their equipment and an ultrasound probe, they puncture the follicles in the ovaries, and aspirate the eggs. These eggs then travel from the ovaries, in a tiny wire-like tube, until they’re finally settled in a laboratory tube (It’s like a fun water slide from the ovaries till the lab tube). This tube is what reaches the embryologist, who then begins their “find the egg” hunt, by pouring the fluid into dishes, and setting apart the eggs to be frozen.

After that, the embryologist checks for any mature eggs. The mature ones are then frozen in liquid nitrogen. 

Embryo freezing to preserve fertility 

Embryo freezing is also a common procedure but it’s done to preserve the fertilised product of an egg and sperm. In a way, this preserves you and your partner's fertility- or to be more precise, the fertilised product, a tiny ball of cells capable of growing into a baby.

How does embryo freezing work? 

Embryo freezing has two steps- retrieving the sperm and egg out of the body. For the egg, an egg retrieval is done, and for the sperm, a sample is requested via ejaculation. 

Then, these are fertilised via IVF or ICSI, which are procedures that co-incubate the sperm and egg together or inject a sperm inside the egg. The result? A mix of two genetic components, growing and dividing into cells to form the embryo. 

At day 5-7 of embryo growth, it has to be either transferred- or frozen. This is because labs are only equipped with media that allows embryos to grow until that stage. In cases of embryo freezing, they are frozen away, either earlier during day 2-3 or on either day 5,6 or 7 until future use.

Understanding the differences: egg vs embryo freezing 

Features 

🥚Egg freezing 

🐣Embryo freezing

👨‍🎓 Eligibility

People who menstruate looking to preserve their fertility, undergoing procedures such as IVM+ egg freezing, ovarian tissue freezing, or patients prior to chemotherapy, egg donors.

People undergoing fertility procedures such as IVF/ICSI. 

⏰ Duration

2-4 weeks and only mature eggs are frozen. 

2-6 weeks. The extended duration depends on the growth of the embryo and the day/stage at which it is frozen. 

💰 Cost

£7000-8000 2 including the cost of storage for one cycle

Depends on the clinic, but ranges from £5000-9800. 3

⏭️ Next steps

The next step after egg freezing is either fertilization via sperm or donation (with consent, of course!) 

The next step after embryo freezing is either a timed transfer to the uterus or embryo donation.

💪 Effort 

The procedure requires mental and physical effort from your end. There are medications to be taken on a daily basis and the physical effort of going through the egg retrieval process. 

The procedure requires mental and physical effort from you and your partner's end. Specifically on your end, there are medications and egg retrieval. From your partner's end, it's providing the semen sample. 

❗Risks

Overstimulation due to medication, pain at areas of injection, chances of the cycle being called off due to patient or lab-related factors. You can read more about it in our guide on egg-freezing failure. 

Overstimulation, chance of the cycle being called off if there are issues from the egg retrieval or semen retrieval part. 

💊 Side effects

Minor hormonal fluctuations due to medications, headache, slight pain at injection site, soreness

Hormonal fluctuations due to medications, slight weight gain, bloating, headache, mood swings, pain at injection site

💯 Success rates 

Cycles with frozen donor eggs are more successful than self-eggs. There are no exact statistics available on this in the UK.

36% 4 for frozen embryo transfer cycles

👶 Live birth rates

18% 5with self-eggs and 30% with donor eggs

27% 6for frozen embryo transfer cycles

🫙 Storage

55 years 7

55 years

Egg freezing vs embryo freezing: The Pros and Cons

The pros and cons of egg freezing

🥚Pros

🥚Cons

Provides the possibility of having a child with your own genetic material 8, later on in their life. Plus, you don't need a partner or semen sample for this procedure! 

Risk of mild to moderate ovarian hyperstimulation syndrome 9(although rare!)

Reduces the risk of having genetic abnormalities in the offspring later on (because you're freezing your fertility-in time, and younger ages tend to produce eggs with less genetic abnormalities)

Risk of any egg-freezing failure or cycle cancellations 

Allows for genetic testing of eggs 10, to avoid any maternal disease/syndrome carry-on and plan donor cycles (imagine knowing you have the power to stop a hereditary disease from passing onto your future child!)

Requires budget planning, and the procedure has no refunds once done 

The pros and cons of embryo freezing

🐣Pros

🐣Cons

It's a way of preserving you- and your partner's fertility.

Requires partner sperm or donor sperm to create and freeze an embryo

You can genetically test and choose embryos that seem the most "healthy”normal" physically, and genetically 

Deciding the outcome of leftover embryos post a transfer cycle can be difficult

Helps delay pregnancy and is a shorter procedure post-freezing, compared to just egg-freezing

Risk of damage to embryos during the freezing and storage process

Egg freezing vs embryo freezing: which is right for you? 

Ultimately, it comes down to your choice, combined with a plan and a talk with your healthcare provider. But to help you out, here's a simple self-evaluation checklist that can help you decide: 

Should I go for egg freezing?

Based on your situation and goal, here are some factors to consider:

  • Egg freezing takes a duration of 2-4 weeks. Am I ready for that? 
  • It requires medications on a day-to-day basis, along with constant ultrasound appointments, am I okay with that? 
  • The final frozen egg number may vary compared to the estimates at the beginning. Has my doctor briefed me about this?
  • Have I planned out a budget for egg freezing?  
  • Will I be able to handle my commute to the clinic for the duration of the cycle?
  • Do I have a plan on how to proceed post-egg freezing? (A solid plan isn't necessary! It's okay to plan things out slowly, and step by step)
  • If my plans change in the future, and I end up not using my eggs, am I okay with donating my eggs to another couple in need or for research? 
  • Do I need emotional support, and if I do, do I have the right resources around me? And healthcare providers I can trust?

Should I go for embryo freezing? 

Based on your fertility treatment, medical history, and goal, here are some factors to consider:

  • Egg freezing takes a longer duration of about 4-6 weeks. Am I ready for that? 
  • Requires medication on a day-to-day basis, and ultrasound until the egg retrieval, am I okay with that? 
  • Post my egg retrieval, there's a wait time of 3-4 days to check which eggs have fertilised, and which haven't. Am I willing to understand that these numbers may vary compared to estimates?
  • Have I planned my budget out for the embryo freezing cycle?
  • Do I have a vague idea of how long I want to keep it frozen for?
  • Do I plan to have the frozen embryo transferred, or do I plan to have a child in the future?
  • If not, am I okay with donating the embryos to another couple in need or for research?
  • Do I have the right emotional support around me? And healthcare providers I can trust?

While this isn't an exhaustive checklist, this should give you a brief idea of the things to expect, in your egg or embryo freezing cycle. With this checklist, we hope you also understand the important things that you need within, and around you to partake in the process of preserving your fertility.

How Amilis can help you with your fertility goals 

Be it egg freezing or embryo freezing- we understand that it's a carefully thought-out decision between you and your healthcare provider. 

But it can be tough to navigate once you make your choice - which clinic should I trust? Can I commute to the place? Will I have a smooth journey?

That's exactly where Amilis comes in. Regardless of your decision, your journey to finding the right resources, clinics, or help, starts here. 

If you’re starting with planning out your egg-freezing journey, you can even try Amilis’s personalized quiz to narrow down on your preferences.

Additionally, our vast resources on egg freezing can also help you make informed choices of choosing budget-friendly clinics, and deciding what works for you. 

And don't forget, through it all, we're out here cheering for you 💪.

You've got this!

References
Written by
Navya Muralidhar
MSc Clinical Embryology & Embryologist

An embryologist by degree, and an educator by heart, Navya has completed her Bachelors in Genetics, and her Masters in Embryology and now strives to deconstruct the complex, into educational and informative articles surrounding her field of interest. She's specifically focused on time-lapse technology, IVM, and pre-implantation genetics. When not writing, you can find her at her favourite or newest coffee shop in town, sketching away, or listening to a podcast.