Orchid offers advanced genetic testing for couples who want their child to have the best shot of a healthy life. We talked with IVF laboratory director Dr. Barry Behr, PhD, HCLD, to understand what the embryo growth process is like in the lab.

Dr. Behr walks us through what embryo development looks like and how embryologists take care of the embryos as they’re growing day by day in the lab.

Day 1: fertilization check

The first "success" in the IVF lab is the presence of fertilized eggs. This measurement tells embryologists there are potentially viable eggs that have been fertilized that can now progress onto an embryo. At this point, the fertilized eggs are called a “zygote” or a “two pronuclei (2PN) oocyte.”

Day 1 or 3: morphology check and assisted hatching procedure

At this IVF lab, the approach to growing embryos is to leave the embryo undisturbed as much as possible. “It's just like baking a cake. It doesn't help the cake to check it every 15 minutes,” says Dr. Behr.

What that means is that after the initial fertilization check on day 1, the next time an embryologist would look at the embryo would be on day 5.

If the patient plans to do genetic testing on their embryos, a commonly done procedure is something called “assisted hatching.” This is when the embryologist makes a small hole in the shell that surrounds the embryo to encourage hatching. The purpose of this procedure is to make the embryo sampling easier for the embryologist to perform since some cells will be “waving at us, hanging out of the hole that we created earlier.”

Dr. Behr explains that their approach is to perform assisted hatching on day 1, at the same time fertilization check happens. Some other IVF labs prefer to do assisted hatching on day 3 while checking how the embryos are growing.

Day 5 to 7: blastocyst stage

The last stage for the embryo to reach is the blastocyst stage. This is when embryos are typically sampled for genetic testing.

One important thing to appreciate about IVF is that the process of embryo creation acts much like a funnel and that along the way, some eggs and embryos get lost naturally through the process. As Dr. Behr puts it, “it’s a process of diminishing returns, meaning as you go down the line, the numbers decrease. In a good IVF lab with high-quality embryo growing conditions, one should expect about half of your fertilized eggs to make it to usable blastocysts.”

However, predicted averages can only tell you so much. “We’re not machines; we’re biological organisms, each a little bit different,” Dr. Behr adds, “the combination of everyone's egg and sperm is a little bit different each time. So we can't prognosticate exactly what you're going to get on day 5,” or by the end of the IVF process.

Fertility treatment and reproductive medicine have come a long way since IVF was first introduced over 40 years ago. Today, advanced embryo testing is now available to couples who want their child to have the best shot of a healthy life. Explore how Orchid helps you conceive with confidence.