Is embryo selection overrated? Rethinking a core IVF concept.

Is embryo selection overrated? Rethinking a core IVF concept. 

By Dr. Sonia Gayete-Lafuente, Fertility Specialist Physician-Scientist at CHR, New York 

Here’s a question that might surprise you: What if embryo selection in IVF isn’t as important as we’ve been led to believe? 

For decades, IVF has focused heavily on finding ‘the best embryo’. The assumption has been that if we can just identify it, outcomes will dramatically improve. However, when you really look at the data, something interesting is revealed. 

Despite tens of thousands of published articles on embryo selection, there’s no evidence that selecting embryos beyond standard morphology significantly improves cumulative pregnancy or live birth rates in unselected IVF populations. And this makes sense, because no embryo selection technique will ever make the embryos better. If anything, at most, it may help identify the embryo that appears “strongest” or more likely to succeed in a cohort and transfer it first. In the best-case scenario, this may improve outcomes measured per transfer or shorten time to pregnancy in selected patients with a favorable prognosis. However, these potential gains come at the cost of additional embryo manipulation and stress -including extended culture, biopsy, freezing, thawing, and genetic testing- which may result in embryo loss or compromise reproductive potential through cumulative attrition, while also adding costs, complexity, and delays to treatment. 

And still, we will not be increasing the overall cumulative chance of having a baby from the embryos produced in a given cycle. 

Yet for years, IVF research has heavily focused on post-retrieval technologies: time-lapse imaging, AI scoring systems, genetic testing strategies, and a long list of IVF unvalidated add-ons…. 

But why don’t we shift most of our efforts to create healthier embryos in the first place? Maybe the future of IVF is less about sorting embryos after retrieval and more about improving biological conditions before the retrieval happens, through deepening our understanding of ovarian metabolism, the follicular microenvironment, the physiology of aging, mitochondrial health, and specially individualizing patient preparation and ovarian stimulation protocols to ultimately enhance egg quality. 

Ultimately, the strongest embryos come from having healthier ovaries and more competent eggs to begin with. That’s an important perspective for the field; not because embryo selection is completely useless, but because perhaps we’ve expected too much from it. And as IVF continues to evolve, we should always be willing to question long-standing assumptions, even the ones that seem foundational. That’s how real progress happens.