Only REI’s Should Do Egg Retrievals? Let’s Do The Math

David Sable
2 min readSep 24, 2023


You can believe two things at once.

I believe that oocyte retrievals for in vitro fertilization (IVF) are best performed by fellowship-trained reproductive endocrinologists (REI’s).

I also believe that anyone who needs IVF in order to have a family should have access to it.

But when does our intention to make IVF available to everyone who needs run in the constraint of insisting that only REI’s perform the egg retrieval?

Let’s do the math.

The data dump:
1500 REI’s in the US, 1250 practicing (Stadtmauer et al.)
2020 CDC statistics: 133,000 oocyte retrievals to produce approximately 75,000 live births for women using their own eggs
Number of retrievals per active REI: 106 per year, 2.3 per week, 46 work weeks/yr

In the past, I modeled IVF demand from the ground up, starting with indications and prevalence/incidence statistics for infertility, recurrent loss management, genetic disease prevention, LGBTQ needs, and oncofertility. Using very conservative assumptions, I came up with a US need for enough IVF capacity to produce at least 1.1 million babies per year. I did not model egg freezing for risk mitigation for infertility (some call it elective egg freezing) since I lacked confidence the accuracy of the model.

For our purposes, let’s be even more conservative, and estimate IVF needs only sufficient to bring us back to population replacement rates. For the US, this means making up a shortfall of about 827,500 babies per year.

In 2020, we performed 133,000 oocyte retrievals and produced 75,000 live births. If we maintain a similar ratio, we would need to perform 1,467,000 egg retrievals.

Instead of performing 2.3 retrievals per week, each active REI would be responsible for 25 retrievals per week for patients trying to conceive that year, using their own eggs.

Can every REI scale this part of their work load 10x? Does every REI want to? When does fatigue set in and negatively impact the same outcome that we are trying to optimize?

Complicated questions, but like with all engineering problems, doing the math helps.



David Sable

bio fund manager, Columbia prof, ex-reproductive endocrinologist, roadie for @PriyaMayadas. I post first drafts.