This post explains the process of using frozen eggs, including thawing, fertilization, and embryo development, to help readers understand the factors that can affect success rates. It also clarifies that pregnancy rates using fresh and frozen eggs are similar, but success depends on factors like the number of eggs retrieved and age.
When you've decided to use your frozen eggs to start a family, it's essential to understand the process and the factors that can affect the success rates. In this post, we'll walk you through the steps involved in using your cryo-preserved eggs and discuss the typical success rates at each stage.
The Thawing Process
As mentioned in our previous post on the egg retrieval process 3 Facts Most People Get Wrong About Egg Freezing, not all eggs will survive the thawing process. Typically, about 85% of mature eggs will survive the thaw. The eggs that do survive will then be fertilized using a procedure called intracytoplasmic sperm injection (ICSI) where a single sperm is injected into each egg.
Embryo Development
After fertilization, the eggs will begin to develop into embryos. Generally, about 50% of fertilized eggs will develop into a blastocyst. This varies from patient to patient.
A Typical Scenario
Let's walk through a typical scenario to better demonstrate the decreasing number of embryos. If 15 follicles develop, the retrieval may yield 12 eggs, 10 of which are mature. Of those 10 mature eggs, 9 will survive the thaw, and 7 are likely to fertilize successfully. Typically 2-4 blastocysts result. These numbers can vary significantly on a case-by-case basis.
Factors Affecting Success Rates
It's important to note that in some cases, no eggs retrieved will fertilize successfully or develop properly. Even if they do develop, there's a possibility that no embryos will reach the final stage of development and be suitable for transfer or freezing. Success rates are highly dependent on the number of eggs retrieved and your age when the eggs were frozen.
Pregnancy Rates
Most studies show that pregnancy rates using fresh and frozen eggs are approximately the same. Pregnancy rates decrease over time, which is why it's recommended to freeze more eggs as you age. The processes used by the embryology team are designed to optimize the development of embryos that are most likely to result in pregnancy.
Conclusion
Using your frozen eggs is a complex process with several stages, each with its own success rates. By understanding these stages and the factors that affect success, you can be better prepared for the journey ahead. If you have any questions or concerns, don't hesitate to reach out to your fertility specialist for guidance and support.
The content on this blog is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider before making any health-related decisions or implementing any medical information shared here.
