Success Rates: Fresh Vs. Frozen Donor Eggs

Choosing to build a family with the help of donor eggs is a significant decision, and one of the biggest choices intended parents face is whether to use fresh or frozen donor eggs. Both options have advantages and potential drawbacks, and understanding the differences can help you feel more confident as you move forward with your plans.

This article will break down what we know about success rates, as well as practical considerations for both fresh and frozen donor eggs. We’ll look at the latest research, explain what the numbers mean for you, and discuss the real-life factors that might make one option a better fit than the other. While there’s no universal right answer, having clear information can help you decide what’s best for your family.

Fresh vs. frozen donor egg IVF

Before we look at the data, it’s helpful to understand what we mean by fresh or frozen cycles. In donor egg IVF, there are two big questions:

• Egg: Was the egg frozen and thawed before fertilization, or was it “fresh”?
• Embryo: Was the embryo frozen and thawed before transfer, i.e., for genetic testing, or was the embryo “fresh”? 

From these two questions, you get four possible combinations:

1. Fresh egg + fresh embryo transfer: Egg retrieved → fertilized → embryo transferred immediately
2. Frozen egg + fresh embryo transfer: Frozen egg thawed → fertilized → embryo transferred immediately
3. Fresh egg + frozen embryo transfer: Egg retrieved → fertilized → embryo frozen → transferred later
4. Frozen egg + frozen embryo transfer: Frozen egg thawed → fertilized → embryo frozen → transferred later

There are many reasons you would choose one of these combinations over another. For instance, genetic testing of the embryo may be important to you if you’d like to choose the gender. Or, perhaps you want to get pregnant as soon as possible, and you know that frozen eggs will save months of time. You can read more about the difference between a “fresh” vs “frozen” transfer here, and the benefits of each. 

Success rates

Research has found that outcomes are relatively similar. However, fresh donor eggs with a fresh embryo transfer have historically had a small edge over all other cycles.

An analysis of 135,085 donor egg cycles from U.S. fertility clinics found that:

• Clinical pregnancy rates are slightly lower with frozen donor oocytes, especially in fresh embryo transfers.
• Live birth rates are slightly lower with frozen donor oocytes for both fresh and frozen embryo transfers.
• Miscarriage rates are slightly higher with frozen donor oocytes, significantly so in fresh embryo transfers.
• Among singleton live births, the likelihood of delivering a term, healthy birthweight baby is similar between fresh and frozen donor oocytes.

That said, the gap between fresh and frozen egg success rates has narrowed over time, and many fertility doctors consider frozen donor eggs a highly effective option.

Why the difference in success rates?

The difference in success rates is likely due to a few key factors related to the biology of the eggs and the logistics of treatment cycles.

First, frozen donor eggs are typically sold in small batches—often around six eggs—while fresh donor cycles usually yield a much larger number of eggs. This gives clinics more embryos to work with in fresh cycles, allowing better selection of high-quality embryos, which may improve implantation and pregnancy outcomes. The more eggs you have, the more likely you are to succeed. 

Second, the freezing and thawing process itself can introduce stress to the eggs. Although modern vitrification (the current rapid freezing method) is very effective, it’s still possible that some eggs don’t survive the thawing process or experience subtle cellular changes that affect fertilization or embryo development.

Lastly, patients using frozen donor eggs may have fewer embryos available overall, which could limit options for genetic testing or multiple transfer attempts.

Despite these differences, it’s important to keep in mind that the gap in success rates is relatively small, and once a pregnancy is established, the chances of delivering a healthy, full-term baby are nearly identical between fresh and frozen donor eggs. The right choice often comes down to timing, cost, donor availability, and what fits best with your personal and medical circumstances.

Other considerations

Both fresh and frozen donor eggs can result in healthy pregnancies and live births. However, there are some other factors to weigh:

• Medication protocols: Fresh donor egg cycles require the recipient to take medication to synchronize with the donor's cycle, which may add complexity. Frozen eggs allow for more flexibility in planning the embryo transfer.
• Meeting the donor: Some intended parents prefer the ability to choose a fresh donor and possibly meet or communicate with them. With frozen eggs, this is more difficult. 
• Cost: Fresh donor egg cycles tend to be more expensive because they involve a longer process, including synchronizing the donor’s and recipient’s cycles, stimulating the donor’s ovaries, retrieving eggs, and fertilizing them in real-time. 
• Risk: With frozen eggs, you take some of the risk out of the process. That’s because every step of the process involves a potential drop-off—such as the donor’s response to medication, the number of eggs retrieved, or fertilization outcomes—and with frozen eggs, many of these variables have already been addressed, giving you more predictability.
• Time: With fresh donor eggs, the process is longer and requires more coordination. If the donor's cycle is canceled or the retrieval does not produce enough viable eggs, it can lead to delays. Frozen eggs, on the other hand, are ready to use immediately, making the process faster and more predictable.

Cofertility offers both fresh and frozen eggs. You can learn more about our pricing here. 

Making the right choice for your family

There’s no single right answer when it comes to choosing between fresh and frozen donor eggs. What works best will depend on your priorities, budget, and timeline.

Both fresh and frozen donor eggs have helped thousands of families welcome healthy babies, and both options are backed by solid science. While fresh eggs have a slight advantage in success rates, frozen eggs offer convenience and a faster, smoother, more predictable process. Understanding the trade-offs can help you make an informed decision that aligns with your goals.

If you’re considering donor eggs, please reach out to us! No matter which path you take, the most important thing is choosing the option that feels right for you and gives you the best chance of building your family.