How to Read Embryo Grading Charts

As you navigate your fertility journey, learning how to read IVF embryo grading charts can help you and your family  understand why some embryos may be better for transfer than others.

Embryo grading charts assess the quality of embryos created through in vitro fertilization (IVF). How to read embryo grading scales depends on whether you are looking at a scale for day 3 or day 5, as each day of development has different characteristics.

This article will help you understand embryo grading charts and success rates.

Fertility clinics can help you create embryos and determine embryo grades. Contact us to find a fertility clinic near you.

Day 3 Embryo Grading Charts

On day 3, embryos are evaluated based on three main criteria:

• Cell Number: A healthy embryo typically has between 6 and 10 cells.
• Symmetry: Symmetrical embryos are generally seen as more viable.
• Fragmentation: This refers to the presence of cell fragments; lower fragmentation rates indicate better quality.

The Day 3 grading scale usually ranges from 1-4 or A-D, depending on the facility, with 1 or A being the highest quality and 4 or D being the lowest.

Here’s what each grade indicates about the day 3 embryo:

Day 3 charts are simpler than charts used for day 5 grading because embryos are not as developed on day 3. The quality of an embryo may change depending on further development, which is why many families choose to wait until day 5 to determine which embryos will be used in IVF.

Learn more about IVF success rates here.

Day 5 Embryo Grading Charts [Gardner System]

By day 5, embryos have developed into blastocysts, which are more advanced structures.

A blastocyst is a stage of embryonic development that occurs around five days after fertilization. At this point, the embryo has differentiated into two main cell types: the inner cell mass (ICM), which will become the fetus, and the trophectoderm (TE), which will become the placenta.

A day 5 embryo grade is made up of 3 components:

Together they read 1AA-6CC.

Expansion (1-6)

Expansion measures how much the blastocyst has expanded. More expansion demonstrates advanced development, which is ideal for implantation.

Inner Cell Mass Quality

This group of cells will form the fetus.

Trophectoderm Quality

This outer layer will develop into the placenta.

Embryo Quality and Success Based on Embryo Grading Charts

Research indicates that higher-grade embryos are generally associated with better success rates in IVF.

In one study, AA embryos resulted in a 41% live birth rate, while BB embryos resulted in a 31% live birth rate and CC embryos were associated with a 13.1% live birth rate. But these statistics depend on several factors.

However, it’s essential to remember that while embryo grading is a useful tool, it is not a guarantee of success or failure.

Embryo grading is one of several factors that affect success, including the age and health of the carrier.

If you have low-graded embryos, surrogacy may increase your chances of successful pregnancy. Contact a surrogacy professional now or learn more here.

Frequently Asked Questions

Read more about common questions related to reading embryo grading charts:

Is 4AA better than 5AA?

A 5AA embryo is generally considered better than a 4AA due to its more advanced stage of development and overall quality.

What is a good embryo grading?

A good embryo grading typically includes Grade A or B embryos, which indicate optimal development and a higher likelihood of successful implantation.

Can poor quality embryos become healthy babies?

Yes, it is possible for poor quality embryos to result in healthy pregnancies, although the chances may be lower compared to higher-grade embryos.

Why are my embryos poor quality?

Several factors can contribute to poor-quality embryos, including maternal age, health issues, and the quality of sperm used for fertilization.