Gardner and Sakkas developed a score for evaluating the viability of a fertilized embryo based on changes seen during the first 5 days (120 hours) after in vitro fertilization. This can help determine if the embryo is suitable for implantation. The authors are from the Colorado Center for Reproductive Medicine and Yale University.
Times of assessment after insemination (19 assessments):
(1) 18-19 hours (6 assessments)
(2) 25-26 hours (2 assessments)
(3) 42-44 hours (3 assessments)
(4) 66-68 hours (3 assessments)
(5) 94-96 hours (2 assessments)
(6) 106-108 hours (3 assessments)
|
Parameter of the Fertilized Embryo |
Finding |
Points |
|
size and symmetry of pronucleus at 18-19 hours |
equal |
10 |
|
|
not equal |
0 |
|
relation of pronucleus to polar bodies at 18-19 hours |
aligned |
5 |
|
|
not aligned |
0 |
|
cytoplasm at 18-19 hours |
lacks heterogenicity and granularity |
5 |
|
|
shows heterogenicity and/or granularity |
0 |
|
pronucleus at 18-19 hours |
both nucleolar precursor bodies polarized |
10 |
|
|
both nucleolar precursor bodies not polarized |
10 |
|
|
1 nuclear precursor body polarized |
0 |
|
difference in the number of nucleolar precursor bodies at 18-19 hours |
< 3 |
10 |
|
|
>= 3 |
0 |
|
polar bodies at 18-19 hours |
not displaced from each other |
10 |
|
|
displaced from each other |
0 |
|
embryo at 25-26 hours |
cleaved to form 2-cell embryo with even blastomeres and no fragments |
15 |
|
|
has not formed a 2-cell embryo with even blastomeres and no fragments |
0 |
|
zygotes at 25-26 hours |
progressed to nuclear membrane breakdown |
5 |
|
|
have not progressed to nuclear membrane breakdown |
0 |
|
number of blastomeres at 42-44 hours |
>= 4 |
10 |
|
|
< 4 |
0 |
|
fragmentation at 42-44 hours |
< 20% |
10 |
|
|
>= 20% |
0 |
|
multinucleated blastomeres at 42-44 hours |
0 |
5 |
|
|
>= 1 |
0 |
|
number of blastomeres at 66-68 hours |
>= 8 |
10 |
|
|
< 8 |
0 |
|
fragmentation at 66-68 hours |
< 20% |
10 |
|
|
>= 20% |
0 |
|
multinucleated blastomeres at 66-68 hours |
0 |
5 |
|
|
>= 1 |
0 |
|
compaction at 94-96 hours |
present |
10 |
|
|
absent |
0 |
|
blastocoele formation at 94-96 hours |
present |
15 |
|
|
absent |
0 |
|
blastocoele cavity at 106-108 hours |
full |
10 |
|
|
not full |
0 |
|
inner cell mass at 106-108 hours |
with numerous cells tightly packed |
15 |
|
|
not with numerous cells tightly packed |
0 |
|
trophectoderm at 106-108 hours |
many cells forming epithelium |
10 |
|
|
no or few cells forming epithelium |
0 |
total score =
= SUM(points for all of the findings)
Interpretation:
• minimum score: 0
• maximum score: 180
• The higher the score the more perfect the embryo.
Specialty: Obstetrics & Gynecology
ICD-10: ,
