Comprehensive Calculator Guide
This calculator estimates the chance of at least one baby from frozen eggs, by your age at freezing and the number of mature eggs, and the eggs needed for a 50%, 75% or 90% chance. 15 eggs frozen at 33 give about an 89% chance; 10 eggs at 38 about 43%. It uses a model published in Human Reproduction in 2017.
How it works
Goldman and colleagues (2017) combine the chance an egg survives thawing and becomes a blastocyst, which falls with age; the share of blastocysts that are chromosomally normal, from 57.4% before 35 to 12.7% at 44; and a 60% live-birth rate per normal embryo. The chance of at least one baby = 1 − (1 − chance per egg) to the power of the number of eggs.
Age matters most: 20 eggs give about 93% at 34, 75% at 37 and 37% at 42. Many scholars permit egg freezing provided the eggs are used only within marriage, with the husband, and stored so they can’t be mixed up.
How to Use
- Enter your age at freezing.
- Enter the number of mature eggs frozen or expected.
- Press “Estimate my chances” to see the chance, expected embryos and eggs needed.
Formula Used
Per egg = 0.6 × euploid share × blastocyst chance | At least one baby = 1 − (1 − per egg)^eggs
Practical Examples
- Example 1: 33 with 15 eggs
- About 13.8% per egg, about 6 blastocysts (3.4 normal), and an 89% chance; 5 eggs for 50%, 10 for 75%, 16 for 90%.
- Example 2: 38 with 10 eggs
- About 5.5% per egg and a 43% chance; 13 eggs for 50%, 25 for 75%, 41 for 90%.
Important Tips
- Check ovarian reserve (AMH) before deciding.
- Ask the clinic for its own thaw-survival and success rates.
- For medical reasons such as chemotherapy, discuss it early.
Common Mistakes to Avoid
- Treating freezing as a guarantee.
- Counting all retrieved eggs instead of mature ones.
- Delaying in the hope that more eggs will make up for age.
Frequently Asked Questions
- How many eggs should I freeze?
- In the mid-thirties about 10–20 for a 75% chance; many more after 40.
- What is the best age?
- Before 35, when the share of normal embryos is highest.
- Is the chance per attempt?
- No, it’s the chance of at least one baby from all the eggs together.