IVF Embryo Grading

IVF embryo grading not only helps assess the quality of embryos created through in vitro fertilization but also plays a crucial role in guiding decision-making throughout your fertility journey.

This article will help you understand the basics of IVF embryo grading and make the best choices on your fertility journey.

If you don’t have embryos, fertility clinics can help you create embryos and determine embryo grades.

Contact us to find a fertility clinic near you.

Once you have embryos, IVF and surrogacy can be great options depending on your circumstances.

Learn more about  surrogacy here.

What is IVF Embryo Grading?

Embryo grading for IVF is a simple way to evaluate how well embryos are developing after fertilization. During IVF, embryologists grade embryos based on factors like cell number, appearance and structure.

This assessment helps fertility specialists predict which embryos may have the best chance of successful implantation in the uterus and successful pregnancy.

Embryo grading plays a role in deciding which of your embryos to transfer, freeze or discard, improving the chances of IVF success.

It’s important to note that while embryo grading is a useful tool, it is not a definitive predictor of success.

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

Contact a surrogacy professional and find out if a pre-screened surrogate may increase your odds of pregnancy.

IVF Embryo Grading Scale: Day 3 Embryos [Cleavage]

On day 3, grading in IVF is primarily assessed based on:

• Number of Cells: A healthy embryo typically has between 6 and 10 cells at this stage.
• Fragmentation: This refers to the presence of uneven cell fragments. Lower fragmentation indicates better quality.
• Symmetry: Symmetrical embryos are often considered higher quality than asymmetrical ones.

Day 3 embryo grading often uses a scale from 1 to 4 or A to D, where grade 1 or A indicates the best quality (even cells, little to no fragmentation) and grade 4 or D indicates poor quality (irregular cells and significant fragmentation).

Day 3 grading scale:

• Grade 1 or A: 8-10 cells, low fragmentation, and symmetrical.
• Grade 2 or B: 6-7 cells, some fragmentation, and mostly symmetrical.
• Grade 3 or C: Less than 6 cells, high fragmentation, and asymmetrical.
• Grade 4 or D: Asymmetrical with heavy fragmentation.

IVF Embryo Grading Scale: Day 5 Embryos Embryo  [Blastocyst]

On day 5, embryos reach the blastocyst stage. At this stage the embryo has developed from a clump of cells into a form with differentiated parts.  After the embryo reaches the blastocyst stage, it can be assessed based on more complex criteria.

These criteria include:

• Inner Cell Mass (ICM): This will become the fetus and is graded A to C based on its development.
• Trophectoderm: This outer layer forms the placenta and is graded A to C.
• Degree of Expansion: This measures how much the embryo has expanded and is graded from 1 to 6, with 6 being complete expansion.

An example of a day 5 embryo grade for IVF would look something like 5AA.  Here’s a breakdown of each component:

• Day 5 Grading ScaleGrade A (High quality): A well-defined ICM and trophectoderm – high likelihood of implantation.
• Grade B (Good quality): Visible ICM and trophectoderm.
• Grade C (Poor quality): Minimal definition of ICM and trophectoderm – low likelihood of implantation.

What Qualifies as a “Good” or “High-Quality” Embryo?

A high-quality embryo is generally one that is graded A or B, meaning it has a good number of cells, low fragmentation, and shows clear signs of healthy development. These embryos are often preferred for transfer or freezing. However, the determination of “good” may vary depending on your fertility clinic, and some fertility clinics may have higher success rates.

You should know that even low-grade embryos still have a chance of successful pregnancy. If you have low-graded embryos, surrogacy may increase your chances of successful pregnancy. Contact a surrogacy professional now or learn more here.

How Embryo Grading Fits into IVF Decision-Making

While embryo grading provides valuable information, it’s important to understand that it is not a guarantee of success. Grading helps fertility specialists and families make informed decisions, such as:

• Selecting embryos for transfer to the surrogate.
• Determining which embryos to freeze for future use.
• Correlation Between Embryo Grades and IVF Success

Research has shown a correlation between higher-grade embryos and increased success rates in IVF. However, it’s crucial to remember that factors such as maternal age, overall health, and the uterine environment also play significant roles in the likelihood of a successful pregnancy.

By understanding the grading of embryos in IVF, you can navigate your fertility journey with greater confidence.

Frequently Asked Questions

Families who are interested in IVF embryo grading commonly ask these questions:

What is the best grade of embryos in IVF?

The best grades are typically Grade A embryos, as they indicate optimal development and a higher likelihood of successful implantation.

Is a 4AA or 5AA embryo better?

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

What is Day 3 grading in IVF?

Day 3 grading involves evaluating embryos based on cell number, fragmentation, and symmetry, helping to assess their viability for implantation.

Can a 5AA embryo be a girl?

Yes, a 5AA embryo can be either male or female, as embryo grading does not determine sex. The genetic sex is determined at fertilization.