Should You Freeze Eggs or Embryos?

Let’s talk about fertility preservation; specifically, whether you should freeze your eggs or freeze embryos. 

As a reproductive endocrinologist who’s been helping people preserve their fertility and build their families for over 15 years, I chat with patients about preserving their fertility all the time. (In fact, I have an entire YouTube series on egg freezing, which answers questions like when you should freeze your eggs and who should think about doing egg freezing.) 

In this blog post, I’ll help you learn the differences between and considerations for freezing eggs versus embryos so you can make the right decision for you. 

What you’ll read online.

It’s true—we’ve been freezing embryos longer in our field than we’ve been freezing eggs. For this reason, online resources can be misleading and say that more is known about freezing embryos than eggs. 

I’ve been a reproductive endocrinologist for over 15 years, and my recommendations have changed over time with advances in technology. When I was in my reproductive endocrinology and infertility fellowship at Stanford University in the mid-2000s, the majority of fertility preservation was offered to women diagnosed with cancer who wanted to preserve fertility before chemotherapy and radiation. Egg freezing was very new, and we had limited data to counsel patients on success in the future, so I would suggest that women freeze embryos, even with donor sperm. That was a lot to process in the middle of a cancer diagnosis and treatment: losing future fertility, going through egg retrieval, and choosing donor sperm to create embryos. Fast forward to today, and now I can confidently offer egg freezing for anyone that wants to preserve their fertility without committing to a sperm source.

In my practice Pacific NW Fertility in Seattle, WA, we’ve been freezing, thawing, and having success with cryopreserved eggs since 2009. We have incredible success rates because of the lab directors, experience, and technology within our clinic. If someone is ready to freeze their fertility, I feel very confident that we could do every egg or embryo with success. Be sure to ask about the experience of the lab wherever you have your fertility preservation treatment.

For couples, there are pros and cons to freezing eggs and embryos. 

I'm seeing more couples wanting to freeze their fertility. For this couple, one person will have eggs, and the other has sperm. They aren’t ready to start their family, but they know they want to have kids together someday. 

The couples will often ask if they should freeze eggs and sperm separately or if they should freeze embryos. There are pros and cons to both options. 

Whether you freeze eggs or embryos, the process for the person with eggs will be similar. They’ll be given gonadotropins for about two weeks before the egg retrieval. (My video on preparing for IVF provides an overview.) 

Here are the pros of freezing eggs instead of embryos: 

1. Lower cost (now). However, there will be additional costs in the future to thaw the eggs, fertilize with sperm, create the embryos, potentially test the embryos, and then do an embryo transfer. 

2. Less ethical challenges. Some people feel the same about eggs and embryos, but in general, some have an easier time discarding unfertilized eggs over embryos (which are fertilized). 

3. Less potential disputes. If the couple doing fertility preservation splits up or changes their mind about family building, that could make things challenging when it comes to the embryos. In egg freezing, the eggs belong to the individual who had the retrieval. As soon as embryos are made, things can get complicated if the couple splits up or changes their minds. 

Talking about breakups when thinking about creating embryos for future family building can be tough, but I often advise couples to see a reproductive lawyer before creating embryos to solidify intent.

A con with egg freezing is that the potential of the eggs isn’t known until we try to fertilize. (This is part of why a trustworthy lab is so important.) There are wonderful egg freezing calculators that can predict the future success rate. You can see that the odds of positive outcomes decrease with age and decrease with obtained eggs. This calculator isn’t real life, but it’s interesting to explore.

The pro of freezing embryos: 

1. You have more knowledge about what’s frozen. Once you take an egg and sperm to an embryo stage, especially if there is genetic screening, there’s at least a 70% chance of a live birth with a single embryo transfer. If somebody wants to have two kids in the future, the best way to optimize your odds is to have four to six euploid embryos frozen. (I have patients with two embryos and they have two kids, but in reality, not every embryo is going to be a baby.) The more embryos you have frozen, the better chance you'll have of success in that family of your dreams in the future. 

And the cons of freezing embryos: 

1. Freezing embryos is a higher cost now. You’ll be paying for the fertilization and for the genetic screening, which is more expensive than freezing eggs (which defer those costs to later). 

2. It can be ethically challenging to discard embryos. This is important to discuss with your partner. 

3. There's a higher chance of dispute between partners as life changes. If the two people who have created embryos together change their goals in the future, it can be tougher to work through and find a compromise. 

Fertility preservation is an incredible option for people. 

Whether you’re freezing eggs or creating embryos to freeze, there are pros and cons: 

• Egg freezing is less expensive in the present, but it's a deferred cost. 

• Embryo freezing is more expensive in the present. 

• With embryos, you know a bit more about what you have frozen in terms of outcomes. 

• Ethically, some people have a harder time discarding embryos than eggs.

• If you create embryos, you can’t unfertilize them, which can be a point of dispute in couples who grow apart in the future. 

I hope this blog post was useful. If you have any other questions, please comment on my YouTube video. Be sure to stick around for more learning. 

PS. If it’s of interest, check out the new edition of my book Not Broken.