Embryo Grading System
Standardized morphological assessment criteria used to evaluate embryo quality and select the best embryos for transfer.
Full Definition
Embryo grading systems are standardized methods used by embryologists to assess embryo quality based on morphological characteristics such as cell number, symmetry, fragmentation, and developmental stage. The most common system grades blastocysts on expansion, inner cell mass quality, and trophectoderm quality using letter grades (A, B, C, D). These assessments help clinicians select the highest quality embryos for transfer and determine which embryos are suitable for cryopreservation. While grading provides valuable information, it does not guarantee pregnancy success or predict genetic normalcy.
Usage
Usage note: Multiple grading systems exist; specify which system is being used in clinical documentation.
In Context
- "The day 5 blastocyst received a grade of 4AA using the Gardner grading system." — Embryology report
- "Embryo grading systems help standardize quality assessment across different laboratories." — Quality assurance protocol