Table 2. Demographic data of patients undergoing intracytoplasmic sperm injection
Morphokinetic parameter (h) Winter Autumn Spring Summer p
n:2,692 n:1,843 n:2,801 n:1,040
tPNa 6.8±0.7a 6.4±0.8b 6.8±0.6a 6.3±0.1b < 0.01
tPNf 24.2±1.6 24.4±1.2 24.2±1.0 24.0±1.0 0.089
t2 26.7±1.7 26.9±1.3 26.9±1.1 26.5±1.1 0.059
t3 37.4±2.0 37.7±1.5 37.4±1.3 37.2±1.3 0.124
t4 39.1±2.1 39.3±1.5 39.2±1.3 38.9±1.3 0.362
t5 49.9±3.0 50.0±2.2 49.9±1.9 49.8±1.9 0.943
t6 53.0±3.0 52.6±2.2 52.7±1.9 52.8±1.9 0.774
t7 55.9±3.3 55.2±2.4 55.6±2.1 55.4±2.1 0.321
t8 59.6±3.8 58.7±2.8 59.3±2.4 58.9±24.1 0.190
tM 90.1±4.2a 88.6±3.1b 88.8±2.6b 88.1±2.5b > 0.01
tSB 102.5±4.1a 100.7±3.0b 100.9±2.5b 99.9±2.5c > 0.01
tB 111.4±4.8 110.2±3.5 110.6±2.9 110.0±2.8 0.08
s1 2.3±0.9 2.2±0.7 2.3±0.6 2.2±0.6 0.621
s2 1.4±0.9 1.3±0.7 1.3±0.6 1.3±0.6 0.381
s3 7.7±2.6a 7.1±1.9a,b 6.8±1.6b 6.7±1.6b > 0.01
cc2 8.9±1.7a 8.8±1.3a 8.2±1.0b 8.0±1.0b > 0.01
cc3 10.2±2.3a 10.1±1.7 a 9.1±1.4 b 9.5±1.4b > 0.01
KIDScore 4.3±0.9a 4.6±0.7a,b 4.6±0.6a,b 4.8±0.6b > 0.01

Note: Values are means±standard errors, unless otherwise noted. H – hours, tPNa – time to pronuclei appearance, tPNf – time to pronuclei fading, t2 – time to two cells, t3 – time to three cells, t4 – time to four cells, t5 – time to five cells, t6 – time to six cells, t7 – time to seven cells, t8 – time to eight cells, tSB – time to start of blastulation, tB – time to blastulation, s1 – time to complete t2-tPNf synchronous divisions, s2 – time to complete t4-t3 synchronous divisions, s3 – time to complete t8-t5 synchronous divisions, cc2 – duration of the second cell cycle (t3-t2), cc3 – duration of third cell cycle (t5-t3). Different subscripts within the same line indicate statistically significant difference. n: Embryos.