Parameter

Synchronized

Unsynchronized

Mixed

Group comparison

Association with pregnancy

Mean embryo grading at cryopreservation

2.1 ± 0.2

2.1 ± 0.2

2.1 ± 0.2

P < 0.0001 a

(S vs U) P < 0.002

(S vs M) P < 0.002

(U vs M) NS

NS

Mean embryo grading at thawing

2.1 ± 0.3

2.0 ± 0.3

2.0 ± 0.3

P < 0.004 b

(S vs U) P < 0.001

(S vs M) P < 0.021

(U vs M) NS

P < 0.056

Preg + (2.15 ± 0.26) vs

No preg (2.07 ± 0.3)

Maximal embryo grading at cryopreservation

2.3 ± 0.2

2.2 ± 0.2

2.3 ± 0.2

P < 0.037 c

(S vs U) P < 0.012

(S vs M) NS

(U vs M) P < 0.05

NS

Maximal embryo grading at thawing

2.2 ± 0.3

2.1 ± 0.3

2.2 ± 0.3

P < 0.03 d

(S vs U) P < 0.008

(S vs M) NS

(U vs M) P < 0.07

P < 0.023

Preg + (2.30 ± 0.26) vs

No preg (2.2 ± 0.33)