Book Now


A must-attend event for any gay man who wants to become a father. We will discuss the obstacles and unlock the path to parenthood.



17 Sep 2018

Guide: An Intended Parent’s Handbook on Embryo Grading



One of the most exciting steps in an IVF journey is learning that you have viable embryos for a potential transfer to a surrogate or the intended mother for a pregnancy. You’ve made it this far, chosen your donor, performed a successful cycle and you’re now ready to see what you’re working with.

On day one after about twenty four hours, intended parents will learn how many embryos have normally fertilized. Most likely, this number will change in the coming days. On days five and six, the lab will check in with the embryos to see how they’ve progressed.

If you’ve selected to have PGS or PGD performed on your embryos, this is when these biopsies will occur. Otherwise, the embryos will be frozen for storage on these days unless you have opted for a fresh transfer.

While every case is different based on need, here is a general look at the grading table we use at Pacific Fertility Los Angeles to help us make sound judgements on which embryos to transfer for an ideal pregnancy.

Here’s a guide for intended parents on embryo grading, and why days five and six are so important:

Watchful Eye 

Embryos are evaluated morphologically under a high-power microscope and graded based on certain visual criteria determined by experienced embryologists. This information is relayed to the intended parents once solidifed. 

Embryos continue growing in the incubator from the moment they were created. A competent embryo must reach a certain stage of growth based on the number of cells it contains. The day after fertilization, an embryo is made of two 2 cells. Over the next few days, these cells continue to divide to the point that on the 5th day after fertilization, they have created a “sheet” or a blanket of cells. Such an embryo is called a “Blastocyst”. Based on this growth and continued cellular multiplication, blastocysts will be ranked.

The Rankings

The stages of am embryo at this point are:

Early blastocyst


Expanded Blastocyst

Hatching expanded blastocyst

On Day 5 of embryo development, an embryo that has expanded is considered of best quality.

In addition to the stage of cellular multiplication, our embryologists will subjectively grade an embryo based on appearance. This is more of a subjective grading but nevertheless an important one. This grading is from I to III, with I being an excellent embryo and III being a poor embryo. Embryos are evaluated on Day 5. Some embryos are kept until Day 6 and reevaluated.

When you’re ready to start your journey, we can help you create viable, sound, healthy embryos for a pregnancy. Contact us today!

Related Articles