Table 4.

Interaction between the developmental stage of the transferred embryos and the effect of PE on CPRs

Factors	OR (95 % CI)	p-value
Female age (years)	0.930(0.872-0.993)	0.031
No. of transferred TQE	1.102(1.031-1.179)	0.004
Developmental stage	0.842(0.718-0.987)	0.004
Progesterone elevation (ng/ml)ª		<0.001
Developmental stageb PE (ng/ml)
0-0.49		0.369
0.50-0.74		0.099
0.75-0.99		0.921
1.00-1.24		0.828
1.25-1.49		0.861
1.50-1.74		0.799
1.75-1.99		0.058
2-		0.228

Note: TQE: top-quality embryo; OR: odds ratio; CI: confidence interval. developmental stage: cleavage versus blastocyst stage, PEª was defined as an unordered categorical variable according to progesterone levels: <0.50, 0.50-074, 0.75-0.99, 1.00-1.24, 1.25-1.49, 1.50-1.74, 1.75-1.99 and ≥2.00 ng/ml. The 95 % CIs of developmental stage ^bPE were all covered 1