AI SMART SUMMARY
Blastocyst grading describes how a Day-5 or Day-6 embryo is developing. Embryologists evaluate three features—the expansion level, the Inner Cell Mass (ICM), and the Trophectoderm (TE)—to generate grades such as 5AA, 4AB, or 3BB. These grades describe appearance, not genetic normalcy or pregnancy outcomes.
- Three components: expansion, ICM, TE
- Grades do not predict pregnancy
- Day-5 and Day-6 embryos use the same grading system
- Useful for IVF planning and frozen transfers
- All medical procedures handled by licensed fertility clinics
During IVF, one of the most anticipated updates is the embryo grading report. Intended parents often hear that their embryos are graded “5AA” or “4BB,” yet many are unsure what these letters and numbers really mean. For egg donors, understanding grading offers clarity about what happens after retrieval.
This guide explains how blastocyst grading works, what each part of the grade means, and what grading can—and cannot—tell families about embryo development.
EggDonors4All provides education and donor-cycle coordination, while all fertilization, embryo culture, testing, and transfer are performed solely by licensed fertility clinics.
What This Page Covers
- How blastocysts are graded
- What ICM, TE, and expansion levels mean
- The difference between AA, AB, BB, BC, etc.
- Why grading cannot predict pregnancy
- How grading is used in donor-egg and IVF cycles
How Blastocyst Grading Works
Blastocysts are typically graded using three components:
1. Expansion Stage (1–6)
Indicates how developed and expanded the blastocyst is.
2. ICM Grade (A–C)
Represents the quality of the inner cell mass, which forms the fetus.
3. TE Grade (A–C)
Reflects the quality of the surrounding cells, which help form the placenta.
Example Grades
- 5AA – Excellent ICM, excellent TE
- 4AB – Strong ICM, good TE
- 3BB – Good overall structure
- 5BC – Good ICM, fair TE
Important: The first number always refers to expansion stage—not overall quality.
Expansion Stage (1–6): What the Number Means
| Number | Description |
|---|---|
| 1–3 | Early blastocyst; beginning to expand |
| 4 | Fully expanded |
| 5 | Starting to hatch |
| 6 | Fully hatched |
Key Point: A “5” does not mean higher quality—it means the embryo is expanding or beginning to hatch.
ICM Grade (A–C): Inner Cell Mass Quality
The inner cell mass (ICM) becomes the future fetus.
| Grade | Meaning |
|---|---|
| A | Tightly packed, many cells |
| B | Moderately packed |
| C | Fewer cells, less defined |
Common Misunderstanding: A “B” ICM does not mean a baby is less likely—it is simply a structural description.
TE Grade (A–C): Trophectoderm Quality
The trophectoderm (TE) helps form the placenta and supports implantation.
| Grade | Meaning |
|---|---|
| A | Many cohesive cells |
| B | Moderate number of cells |
| C | Fewer, thinner cells |
Both ICM and TE grades provide visual information—not outcome predictions.
Common Blastocyst Grades and What They Indicate
| Grade | Interpretation |
|---|---|
| 5AA | Excellent structure; strong developmental stage |
| 4AB | Very good ICM; good TE |
| 5BA | Good ICM; excellent TE |
| 3BB | Balanced; often frozen for later use |
| 5BC / 4CB | Lower visual quality but still viable |
Important: Lower-graded embryos often lead to healthy pregnancies. Grading is not destiny.
What Blastocyst Grading Cannot Tell You
Grading does not determine:
- Whether the embryo is chromosomally normal
- Whether implantation will occur
- The health of a future baby
- The likelihood of miscarriage
Genetic status requires PGT testing, which is performed by fertility clinics when intended parents choose it.
How Grading Fits Into Donor-Egg IVF
Donor eggs often produce more blastocysts due to:
- Younger ovarian age
- Strong egg quality
- Higher fertilization potential
This can result in:
- More embryos available for freezing
- Increased options for testing
- Multiple future transfer opportunities
Guaranteed Blastocysts
EggDonors4All does not perform embryo grading or medical procedures. Clinics handle all embryology.
A Guaranteed Blastocyst Program may appeal to families who:
- Want a defined minimum number of blastocysts
- Prefer clarity before transfer planning
- Seek structured expectations after previous IVF uncertainty
- Plan surrogacy or international IVF
Frequently Asked Questions
Q. Does a higher grade (AA) always mean a better chance?
Ans. No. Grading is structural, not predictive.
Q. Can lower grades still work?
Ans. Absolutely. Many pregnancies come from BB, BC, and even C-graded embryos.
Q. Is grading the same as genetic testing?
Ans. No. Appearance does not equal chromosome status.
Q. Do Day-6 embryos get graded differently?
Ans. No—they use the same system.
Q. Does EggDonors4All grade embryos?
Ans. No. Only licensed fertility clinics perform grading and medical evaluations.
Related Articles in the Blastocyst
- Blastocyst vs Embryo
- Day-3 vs Day-5 vs Day-6 Embryos
- Blastocyst Success Rates
- Frozen Blastocysts
- Hatching Blastocysts
- Blastocyst Transfer Guide
- Blastocyst FAQ Library
- Why Some Families Choose Guaranteed Blastocysts
Need help understanding your embryo report?
EggDonors4All provides education, donor-matching support, and guidance for families navigating IVF—with all medical services delivered by licensed fertility clinics.
- Explore Guaranteed Blastocysts
- Request Donor Information
- Become an Egg Donor
Serving intended parents and donors across the USA & Canada.
Dr. Veera Saghar
As an Egg Donor Coordinator, she plays a critical role in our company. Her background as a medical graduate from ISRA UNIVERSITY in Pakistan provides us with a solid foundation in the medical sciences. She has seven years of clinical experience practicing in the USA. This has given her firsthand experience when collaborating with patients and their families.
She is responsible for managing the process of egg donation from start to finish. We identify and screen potential egg donors.
- Dr. Veera Saghar
- Dr. Veera Saghar
- Dr. Veera Saghar
- Dr. Veera Saghar
