Table 3. Time-lapse kinetic parameters of good-quality embryo development after IVF in 103 couples, according to the male smoking status.

Values are presented as means ± standard deviation.

t0 = insemination time; tPNa = time to pronuclei appearance; tPNf = time to pronuclear fading; t2-8 = time to 2 cells to 8 cells; tSB = time to initiation of blastulation; tB = time to formation of full blastocyst; cc2 = duration of the second cell cycle; cc3 = duration of the third cell cycle; s1 = time from tPNf to 2 cells; s2 = time division to 3 cells and subsequent division to 4 cells; s3 = time division to 5 cells and subsequent division to 8 cells

Development time from t0 (h)		Smokers (n = 54 embryos, 27 patients)	Non-smokers (n = 160 embryos, 76 patients)	p-value
tPNa		8.2±1.0	8.7±1.4	0.017
tPNf		22.3±2.6	23.4±2.3	0.008
t2		24.7±2.7	25.7±2.3	0.010
t3		34.9±3.3	36.4±3.2	0.004
t4		35.8±3.3	37.4±3.1	0.003
t5		46.9±5.6	49.7±5.6	0.002
t8		54.6±7.1	56.3±7.2	0.118
tSB		92.1±6.4	93.2±6.8	0.282
tB		100.7±6.9	102.0±6.6	0.164
tPNf-tPNa		14.1±2.5	14.7±2.5	0.066
s1(t2-tPNf)		2.4±0.5	2.3±0.5	0.189
cc2(t3-t2)		10.2±1.8	10.7±2.1	0.008
cc3(t5-t3)		11.9±3.8	13.3±3.8	0.052
s2(t4-t3)		0.8±1.5	1.0±1.6	0.340
s3(t8-t5)		7.8±6.5	6.5±6.1	0.236
tSB-t8		37.5±7.2	37.0±7.3	0.644
tB-tSB		8.6±3.3	8.8±3.7	0.818