Choosing a clinic that has a superb lab may be the most important step you can take to ensure that you have a healthy child through IVF. Most embryologists freely admit there is a wide variation in quality when it comes to laboratories, and that a good laboratory can double your chances of success.
Laboratories typically have a singular goal: take eggs and sperm and grow healthy embryos. This is enormously difficult and some labs are better at it than others. Below you can see the variance in success rates between two highly regarded clinics using donor eggs (which are presumably of good quality):
As patients, it is incredibly hard for us to distinguish between an excellent, mediocre and poor laboratory. First, according to our data, only 26% of clinics make it easy to get your questions answered by an embryologist (but many relent if you insist). Second, most of us simply don't know what to look for.
First, make sure that the clinic is doing a sufficient number of cycles to be experienced (roughly more than 200 per year) and that they have the right number of embryologists staffed. Each clinic should have two embryologists and you typically do not want the ratio of cycles-to-embryologists to reach above 150 - 200.
Second, zero in on the laboratory's key performance indicators. They should be able to succesffuly fertliize more than 70% of the eggs they inseminate with ICSI over a given time period, and then be able to turn 40 - 50% of those into blostocyst-stage embryos by the fifth or six day of culturing.
Third, ensure this laboratory has great culture conditions. You want your embryos in an incubator that is kept at 5% oxygen (not 20%), as 5% drives higher success rates. Many clinics still keep their incubators at 20% oxygen levels and this should be considered a red flag. Also, you want to ensure your embryos are kept in an incubator with as few other samples as possible, or within their own chamber. This reduces the risk your embryos will be disturbed when other samples are being tended to, and reduces the likelihood your sample could be mistaken for someone else's.
Finally, consult publicly-reported data to get a sense for how many embryos the clinic is transferring in a fresh cycle (fewer embryos means more confidence in the lab's work), and how well they do with donor egg cycles (since donor eggs are almost always good, this is a decent leveler between clinics).
You may come to realize that your clinic doesn't have its own laboratory. We estimate 15 - 20% of clinics use another laboratory. This isn't necessarily a problem, but it may be harder to get concrete answers on how that laboratory operates. Below we compare the success rates of a major clinic, and the outsourced laboratory the clinic uses for half of its patients.
Unfortunately, there is no meaningful oversight for laboratories in the US. College of American Pathology (CAP) accredition and FDA clearance amount more to "check the box" benchmarks than signifiers of excellence. New York State inspectors are more rigorous, but few laboratories outside of the tri-state area are ever inspected.
Ultimately, patients are very much on their own to determine if they are putting their faith in a laboratory that will diminish their chances of success or give them a meaningful advantage.