From: Evaluation of zona pellucida birefringence intensity during in vitro maturation of oocytes from stimulated cycles
Oocyte stage Score
ZP-BF Score
total
high/positive
low/negative
GV
2.4 ± 4.5*
4.0 ± 3.3§
-3.8 ± 2.6¶
MI
3.0 ± 4.6*
4.7 ± 3.3§
-3.4 ± 2.8¶
MII
3.3 ± 4.3*
4.8 ± 3.5§
-3.0 ± 1.5¶