Table 1.

Patients and treatment characteristics

	Transfer of good quality embryo	Transfer of poor quality embryo	P value	OR(95 % C.I)
Cycles	10625	1096	——
Maternal age	30.26 ± 3.38	31.10 ± 3.89	<0.001
Paternal age	32.14 ± 4.53	33.45 ± 4.89	<0.001
Maternal BMI	22.3 ± 3.31	22.23 ± 3.36	0.52
Cycles with ICSI	4399(41.40 %)	260(23.72 %)	<0.001
Dose of gonatrophin	2389.56 ± 1089.26	3051.62 ± 1496.57	<0.001
Number of oocytes retrieved	13.15 ± 5.69	10.62 ± 6.35	<0.001
Number of fertilized oocytes	8.92 ± 4.34	4.47 ± 3.34	<0.001
Fertilization rate	94764/139741 (67.81 %)	4904/11637 (42.14 %)	<0.001	0.35(0.33–0.36)

Data are presented as the number (%) or mean ± SD. Continuous variables were compared using analysis of variance, and categorical variables were evaluated with chi-squared tests