Deep Dive

Why The Lab Matters

As fertility patients, we often obsess over who our doctor is, the protocols we’re prescribed, and the name of the clinic. While all of these can be important, none of this other stuff matters if our lab is not superb.

You may think of the lab as a commodity: a bunch of worker bees in lab coats all using standardized equipment and procedures. But every lab is unique: who they hire, the techniques they use, and the results they deliver. When we were patients looking at clinics, each told us that their lab “separated them from the pack,” but when we pressed them for either proof or explanation, we got responses back that ranged from the unverifiable to the downright flimsy.

What Happens in The Lab?

The goal of a fertility lab is take eggs and sperm and deliver healthy embryos. That means means preserving incredibly delicate eggs, selecting the best sperm, inseminating the egg, and providing the right amount of heat, oxygen and nutrients to grow embryos to the point where they can ultimately be transferred.

There are literally hundreds of steps and many rely heavily on everything going just right: human intervention, sequence, and organization, equipment working perfectly. Cells at this stage are incredible fragile — keeping them alive is one thing, but growing them so that they are identical to what would be produced in the fallopian tubes, and womb, is another. The margin for error is practically zero, and the consequences of a misstep are grave.

There’s a Ton of Variety in Labs

Just because something is important, doesn’t mean it's worth obsessing over, right? How much sleep do you lose thinking about the brakes on your car, or the fire alarm in your apartment? That’s because they are commodities: there is no distinction in quality and just about everything performs equally well.

You’d think the same would be true for a laboratory, but the truth is labs bear closer resemblance to a restaurant kitchen than a factory floor. Each lab cooks with a unique set of ingredients (media), follows different recipes (how to culture embryos, do they do PGS, or ICSI?), has its own framework for how it hires and trains its chefs (embryologists and andrologists), uses different utensils, mixers, ovens (incubators) and is cooking for either a few hundreds, or a few thousand, customers each year (see cycle volumes at

Results (Definitely) Vary

Given all this, it’s not surprising that nearly every embryologist will tell you that the difference in lab quality across the US is startling. This variance dramatically impacts your chances to have a live birth. In the vast majority of IVF cycles, the laboratory is given mature eggs to work with. And yet at the end of this process, only 30% of cycles deliver a live birth. So what is happening, or getting lost, in between?

Most embryologists tell us that the difference between going to a mediocre laboratory, and a superb laboratory, likely doubles your chances in taking home a baby. That can be hard to prove, because labs receive different quality gametes depending on their patient population.

But there are some circumstances where egg volume and quality is similar between labs, and that is when they receive (presumably good) donor eggs to work with. Below are the outcomes, in those exact circumstances, from two highly-regarded, medium-sized labs. The disparity in results between these labs holds up year after year: outcomes vary from 40% – 70%, depending on what you focus on. So in short, the lab matters. Big time.

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Improving IVF Success Rates: Using Low Oxygen in the Lab

Selecting a clinic is as much about selecting their laboratory as anything else. A key determinant of lab quality is the conditions they use to culture embryos. Using low oxygen in the incubator is preferable, yet a third of laboratories don't do this.

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Is it safe to ship cryopreserved eggs (and embryos)?

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How Long Are Frozen Eggs and Embryos Good For?

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Egg Freezing, Vitrification & Judging Your Lab’s Track Record

With every passing year, fertility treatment relies more and more upon the laboratory's ability to freeze and thaw gametes. Vitrification has forever changed how we store eggs and embryos, and yet the process requires a fair amount of experience, specifically when it comes to egg freezing. Peter Nagy, one of the fathers of vitrification, helps patients ascertain whether their lab is experienced enough to trust.

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The Problem of Mosaic Embryos in IVF

While clinicians are adopting PGS at a rapid rate (now 35% of all IVF procedures), it's now become clear that the results we get from such a test are not as black-and-white as we originally presumed. What is now unclear is how often we are dismissing good embryos, and what we do from here.

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