Ultra-Rapid Freezing and Rapid Freezing Methods in Clinical ICSI Program: Effects on Sperm Biological Characteristics, DNA Methylation Stability, DNA Methyltransferase Activity, and Embryo Morphokinetics

Table 6

Percentage and frequency of cleavage abnormalities between groups.

Cleavage abnormalities	Fresh group (n = 249)	Ultra-rapid freezing group (n = 243)	Rapid group (n = 238)	p-Value
Reverse cleavage	10.4% (26)^a	14.8% (36)^a	14.3% (34)^a	0.29
Direct cleavage	4.8% (12)^a	7.4% (18)^a	5.0% (12)^a	0.39
Multinucleation	2% (5)^a	3.3% (8)^a	3.8% (9)^a	0.31
Uneven blastomeres	35.5% (88)^a	48.6% (118)^b	52.1% (124)^b	0.001
Vacuoles	26.1% (65)^a	31.3% (76)^a	35.7% (85)^a	0.07
Fragmentation	60.6% (151)^a	73.3% (178)^b	80.7% (192)^b	<0.001

Note. The used superscript letters that are similar do not show a significant difference (), but the dissimilar letters show a significant difference ().