10/07/2026
What should you reasonably expect from your IVF cycle?
Many patients assume that our bodies function as an exact science and that their IVF cycle will play out in predictable results. But we soon learn that biology is, in fact, an inexact science, influenced by multiple factors many of which are beyond our control.
Why doesn’t the number of follicles equal the number of eggs retrieved? Why don’t all the eggs become embryos after fertilization? Why aren't all embryos chromosomally normal? Why don’t all embryos successful implant?
Sometimes, it's hard to embrace these realities of biology. But going into your IVF cycle with reasonable expectations will help you better understand and accept the final results.
Let's try an example:
In a hypothetical example of a woman under 35 with normal ovarian reserve, we start with 25 egg follicles retrieved. About 80% of the eggs will be mature and can be fertilized. Of those about 80% will fertilize normally. Of these resulting embryos, only about 40% will make it to days 5-7. Of these, about 60% will test genetically normal.
So, from the 25 egg follicles at retrieval, we are now left with 4 normal embryos to transfer. And assuming a 50-60% implantation rate for each single embryo transfer, you could potentially have 2 pregnancies.
It should be noted that these numbers closely mimic normal human biology for a natural pregnancy. The only difference is that this all happens within they body where we cannot see it 😉
