Table 3.

Multivariable logistic regression model for predicting live birth and relative importance of predictors

Variable Name	Odds ratios (95%CI)	P-value	Marginal PEV (%)	Partial PEV (%)
Number of good-quality embryos transferred		<0.0001a	3.03	1.87
3	2.89[1.83–4.56]	<0.0001b
2	2.77[1.97–3.91]	<0.0001b
1	1.57[1.07–2.30]	0.021b
0	1
Progesterone on the day of hCG injection			1.41*	1.00*
≥1.2	0.59[0.48–0.73]	<0.0001
<1.2	1
Endometrial thickness		<0.0001a	1.37*	0.86*
≥13	1.92[1.46–2.52]	<0.0001b
[10,13)	1.34[1.11–1.63]	0.002b
<10	1
Age		<0.0001a	1.76*	0.76*
≥35	0.48[0.33–0.69]	<0.0001b
[30,35)	0.81[0.64–1.03]	0.084b
[28,30)	1.07[0.82–1.39]	0.640b
<28	1
E2 on the day of hCG injection		<0.0001a	0.77***	0.52*
≥4000	0.80[0.63–1.01]	0.064b
[2500,4000)	1.27[1.04–1.57]	0.022b
<2500	1
Duration of infertility		0.097a	0.76***	0.27**
≥8	0.72[0.53–0.98]	0.036b
[5,8)	0.90[0.70–1.16]	0.431b
[2.5,5)	1.02[0.81–1.30]	0.840b
<2.5	1
Basal serum E2 level
≥35	0.81[0.68–0.96]	0.016	0.25***	0.21**
<35	1
Number of embryos transferred		0.087a	1.35**	0.15**
3	2.23[1.05–4.73]	0.036b
2	1.94[0.92–4.11]	0.083b
1	1
LH on the day of hCG injection
≥2	1.23[0.98–1.54]	0.071	0.25***	0.11**
<2	1

^a P-value of type 3 chi-square test for each variable’s overall effects after adjusting for the other variables

^b P-value of chi-square test between each variable’s subgroups and reference group

***Significantly different from relative importance of number of good-quality embryos transferred at α = 0.001 level

**Significantly different from relative importance of number of good-quality embryos transferred at α = 0.01 level

*Significantly different from relative importance of number of good-quality embryos transferred at α = 0.05 level