Table 3  Comparison of IVF-ET treatment cycle characteristics of the patients in group A, group B and group C.

	Group A (DET with GQEʼs) n = 498	Group B (DET with MQE) n = 179	Group C (SET with GQE) n = 1621	p*
Data presented as mean ± SD. DET: double embryo transfer; GQE: good quality embryo; MQE: mixed quality (one good quality plus one poor quality) embryos; SET: single embryo transfer. a There was a significant difference between DET with GQE and DET with MQE. b There was a significant difference between DET with GQE and SET with GQE. c There was a significant difference between DET with MQE and SET with GQE. d There was a significant difference between DET with GQE, DET with MQE and SET with GQE. * p-values with statistical significance (p < 0.05) are shown in bold.
Maternal age, years	33.5 ± 4.6	34.5 ± 4.3	29.2 ± 4.3	0.001 b, c
Body mass index, kg/m 2	26.6 ± 5.0	26.6 ± 4.5	26.0 ± 4.9	0.054
Total gonadotropin dose, IU	2557.1 ± 1042.3	2898.0 ± 1172.7	2249.3 ± 957.9	0.001 d
Number of mature oocytes	9.3 ± 5.4	7.1 ± 4.0	8.9 ± 5.7	0.001 a, c
Number of fertilized oocytes	5.3 ± 3.5	3.6 ± 2.3	4.8 ± 3.6	0.001 d
Fertilization rate	0.60 ± 0.22	0.55 ± 0.26	0.56 ± 0.25	0.002 d
Endometrial thickness, mm	10.1 ± 2.3	10.5 ± 5.6	10.3 ± 2.3	0.178