Updated by the Progyny Editorial Team. Reviewed by the Progyny Clinical Team — January 2026.
If you’re going through egg retrieval, you may be wondering, “How many eggs will they be able to retrieve… and how many do I need for a successful pregnancy?”
The best thing you can do is have an open discussion with your fertility specialist about your personal situation and what factors play a role in your own unique case. With reproductive medicine, there are simply no magic numbers or guarantees.
Understanding attrition in IVF
Because eggs and embryos go through several stages in IVF, it’s expected that the number at the end will be lower than it was at the start. This is called attrition. You can think of this as a funnel, in which the number of eggs and embryos go down at different points.
- After retrieval, about 80% of the eggs are mature enough to fertilize.
- Out of the mature eggs, about 70% successfully fertilize to create embryos.
- Out of the embryos, about 50% or fewer become blastocysts. A blastocyst is an advanced embryo stage of 100 to 300 cells that forms 5 to 7 days after fertilization, with a good chance of implanting into the uterus. Often, pre-implantation genetic testing (PGT-A) is done to assess the health of the embryo at this stage.
- Out of the blastocysts, PGT-A testing will identify that some embryos have missing or extra chromosomes, which may affect implantation. As we get older, the chances that embryos will successfully implant go down.
For example, a 2023 study in Human Reproduction found the following rates of embryos with the expected number of chromosomes (called “euploid” embryos):
| Age | Rate of euploid embryos |
|---|---|
| Under 35 | 73% |
| 35 to 36 | 54% |
| 37 to 38 | 37% |
| 39 to 40 | 31% |
| 41 to 42 | 23% |
| 43 and over | 5% or less |
Attrition example
To help imagine these attrition numbers, suppose 10 eggs were retrieved for a 40-year-old.
| Milestone | Number |
|---|---|
| Egg retrieval | 10 eggs |
| Eggs are mature enough to fertilize | 8 eggs (80% of 10 eggs) |
| Eggs successfully fertilize | 6 eggs (70% of 8 mature eggs) |
| Embryos become blastocysts | 3 embryos (up to 50% of 6 fertilized eggs) |
| Embryos have favorable PGT-A results | 1 embryo (30% of 3 blastocysts) |
In some cases, having more eggs may help increase the chances of pregnancy, but it’s only part of the overall picture. Also keep in mind, not all patients can (or should) have “maximal” ovarian stimulation that aims to result in many eggs, due to health conditions such as polycystic ovary syndrome (PCOS).
Can I estimate my chances of success?
Your doctor may use your age and results from ovarian reserve testing to predict your chances of a live birth. (Ovarian reserve is the quality and quantity of a person’s eggs, and it’s the main indicator of how many eggs will be retrieved.)
Be sure to have a discussion with your doctor about your personal situation to understand what is optimal for you and what can be done to maximize your likelihood of success.
Here’s what you can do
It’s natural to feel a lot of different emotions and stress when you’re considering or going through egg retrieval. You care deeply about the outcome, and it may seem like aspects of the process are out of your control. That can be really hard.
Please know that personalized support and guidance are available. With that, here’s what you can do right now.
- Ask your doctor anything. You can feel comfortable bringing up any questions or concerns that are on your mind. Together, you and your care team have the best, most complete information about you.
- Reach out to your Progyny Care Advocate. We’re here to provide support, suggest personalized resources, and lend an experienced listening ear.
- Prioritize self-care. Cope with stress in healthy ways that feel right to you, whether it’s reading a good book, talking with a friend, doing deep breathing, or journaling. Carve out time and be good to yourself, just as you would treat a friend.
Disclaimer: The information provided by Progyny is for educational purposes only and is not medical advice. Always consult a qualified healthcare provider for medical guidance.