
What Is Embryo Grading and Why Do We Use It?
What Is Embryo Grading?
Embryo grading assesses the developmental quality of embryos under lab conditions.
It evaluates:
- Morphology – shape, structure, and cell features.
- Developmental timing (morphokinetics) – how fast and precisely an embryo reaches specific developmental checkpoints.
Why Is Embryo Grading Used?
- Helps reduce the risk of multiple pregnancies by transferring fewer, better-quality embryos.
- To identify embryos with the highest chance of implantation and live birth.
- Informs decisions on transfer, freezing, biopsy.
What Does It Tell Us?
- Embryo grading offers insights into:
- Viability
- Development potential
- Transfer readiness
- It's not diagnostic – a high grade doesn't guarantee success, and lower grades can still result in healthy births.
Day 3 vs Day 5/6 Embryos
FeatureDay 3 (Cleavage Stage)Day 5 (Blastocyst Stage)
Developmental Stage6–10 cells100+ cells, organised structures
Transfer/Frozen UseLess commonPreferred for transfer/freezing
Grading CriteriaCell number, symmetry, fragmentationExpansion, ICM, TE quality
Predictive AccuracyModerateHigher – closer to implantation stage
Gardner Grading System (for Blastocysts)
Widely used for Day 5/6 blastocysts:
- Expansion Stage (1–6) – degree of blastocoel expansion.
- Inner Cell Mass (ICM): forms the foetus.
- Trophectoderm (TE): forms the placenta.
Example:
4AA = Expanded blastocyst (Grade 4) with excellent ICM and TE.
Our Clinic’s Advanced Approach
We use combined grading for the most informed embryo selection:
KidScore™ (Morphokinetic Algorithm)
- Analyses time-lapse videos of embryo development.
- Scores based on how closely embryo timing matches ideal patterns.
- Increases objectivity and reduces inter-operator variability.
iDA Score™ (Vitrolife AI Platform)
- Uses artificial intelligence to analyse embryo time-lapse images and predict:
- Implantation potential
- Embryo ranking
- Trained on hundreds of thousands of outcomes.
- Adds a powerful, data-driven layer to traditional grading.
Our system combines morphology + morphokinetics + AI scoring to guide embryo selection with maximum precision.
Key Takeaways
- Embryo grading is essential in IVF but has evolved with technology.
- We combine visual assessment, developmental timing, and AI-powered prediction for best outcomes.
- Our goal: help you achieve a healthy pregnancy, efficiently and safely.