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IVF Embryo Grading Calculator

Understand embryo quality grades and success rates for Day 3 and Day 5 embryos

Medical Disclaimer

Embryo grading is subjective and varies between embryologists and clinics. Success rates are estimates based on published data. Many factors beyond morphological grading affect implantation success, including maternal age, uterine receptivity, and genetic normalcy. Lower-graded embryos can result in healthy pregnancies. Always discuss your specific embryo quality with your fertility team.

Enter Embryo Information

ICM becomes the baby

TE becomes the placenta

Understanding Embryo Grading

Day 5 Blastocyst Grading System

Blastocysts are graded using three components:

  • Number (1-6): Degree of expansion
  • First Letter (A-C): Inner cell mass quality
  • Second Letter (A-C): Trophectoderm quality

Example: 4AA = Expanded blastocyst with excellent ICM and TE

Day 3 Embryo Grading

Day 3 embryos are assessed based on:

  • Cell number: Should be 6-10 cells by Day 3
  • Cell symmetry: Even-sized cells are preferred
  • Fragmentation: Less than 10% is ideal

Success Rate Factors

  • • Maternal age is the strongest predictor
  • • Genetic testing (PGT-A) improves selection
  • • Endometrial receptivity affects implantation
  • • Laboratory conditions and techniques
  • • Fresh vs. frozen transfer outcomes

Common Embryo Grades & Success Rates

Day 5 Blastocyst Grades

4AA, 5AA, 6AAExcellent (60-70%)
4AB, 4BA, 5AB, 5BAVery Good (50-60%)
4BB, 5BB, 3AAGood (40-50%)
3AB, 3BA, 3BB, 4BCFair (30-40%)
3BC, 4CC, Any C gradePoor (20-30%)

Day 3 Embryo Grades

8 cells, <10% fragmentationExcellent (35-45%)
7-9 cells, 10-20% fragmentationGood (25-35%)
6-10 cells, 20-30% fragmentationFair (15-25%)
<6 cells, >30% fragmentationPoor (10-20%)

*Success rates are estimates for women under 35 and vary significantly based on individual factors

Medical Sources & References

  • • Gardner DK, Schoolcraft WB. (1999). "In vitro culture of human blastocysts." In: Towards Reproductive Certainty. Parthenon Publishing.
  • • Alfarawati et al. (2011). "The relationship between blastocyst morphology, chromosomal abnormality, and embryo gender." Fertility and Sterility, 95(2), 520-524.
  • • Capalbo et al. (2014). "Correlation between standard blastocyst morphology, euploidy and implantation." Human Reproduction, 29(10), 2253-2262.
  • • Irani et al. (2017). "Morphologic grading of euploid blastocysts influences implantation rates." Reproductive BioMedicine Online, 34(2), 212-218.
  • • ASRM. (2018). "Blastocyst culture and transfer in clinically assisted reproduction." Fertility and Sterility, 110(7), 1246-1252.
  • • Viñals Gonzalez et al. (2018). "Euploid blastocysts implant irrespective of their morphology." Human Fertility, 21(3), 156-162.