Table 3. Binary Regression analysis' results for the association between BNAN on days 2 and 3 of embryo development and blastocyst formation, quality and hatching status
Predictive variables	Response variable
	Blastocyst formation
	OR	CI
Occurrence of BNAN on D2	0.57	0.50-0.65*
Incidence of BNAN on D2	1.00	0.99-1.00
Embryo with >25 % BNAN on D2	0.61	0.47-0.78*
Occurrence of BNAN on D3	0.67	0.58-0.78*
Incidence of BNAN on D3	0.97	0.95-1.00
Embryo with >25 % BNAN on D3	0.53	0.39-0.72*
	Blastocyst quality
	OR	CI
Occurrence of BNAN on D2	0.56	0.43-0.73*
Incidence of BNAN on D2	1.01	1.00-1.02
Embryo with >25 % BNAN on D2	1.27	0.79-2.06
Occurrence of BNAN on D3	0.85	0.62-1.16
Incidence of BNAN on D3	1.00	0.98-1.02
Embryo with >25 % BNAN on D3	0.69	0.37-1.29
	Blastocyst hatching status
	OR	CI
Occurrence of BNAN on D2	0.66	0.50-0.87*
Incidence of BNAN on D2	0.99	0.98-1.00
Embryo with >25 % BNAN on D2	0.44	0.26-0.73*
Occurrence of BNAN on D3	0.61	0.45-0.83*
Incidence of BNAN on D3	0.97	0.94-1.00
Embryo with >25 % BNAN on D3	0.76	0.38-1.54
Note: BNAN, blastomere with no apparent nucleus; D2, day 2 of embryo development; D3, day 3 of embryo development; OR, odds ratio; CI, confidence intervals; * statistically significant.