Associations of residential greenness exposure during early pregnancy with the risk of spontaneous abortion: the China Birth Cohort Study

Environmental Sciences Europe

Table 2 Associations of residential greenness with SAB

SAB	Unadjusted HR (95% CI)	Model1 HR (95% CI)	Model2 HR (95% CI)	Model3 HR (95% CI)
NDVI_500m
Per 0.1 unit	0.916 (0.889, 0.944)	0.877 (0.845, 0.911)	0.925 (0.852, 0.959)	0.912 (0.877, 0.948)
Q1 (< 0.203)	1	1	1	1
Q2 (0.203–0.291)	0.934 (0.845, 1.031)	0.909 (0.816, 1.013)	1.014 (0.912, 1.127)	0.971 (0.869, 1.086)
Q3 (0.292–0.373)	0.779 (0.702, 0.865)	0.692 (0.613, 0.782)	0.815 (0.725, 0.916)	0.766 (0.673, 0.871)
Q4 (≥ 0.374)	0.792 (0.714, 0.879)	0.686 (0.604, 0.778)	0.820 (0.724, 0.928)	0.773 (0.675, 0.884)
EVI_500m
Per 0.1 unit	0.882 (0.844, 0.922)	0.838 (0.794, 0.886)	0.901 (0.854, 0.950)	0.886 (0.837, 0.938)
Q1 (< 0.116)	1	1	1	1
Q2 (0.117–0.173)	0.936 (0.846, 1.035)	0.909 (0.816, 1.013)	1.004 (0.903, 1.116)	0.970 (0.868, 1.084)
Q3 (0.174–0.231)	0.820 (0.738, 0.910)	0.729 (0.646, 0.823)	0.854 (0.759, 0.960)	0.811 (0.713, 0.922)
Q4 (≥ 0.232)	0.790 (0.711, 0.878)	0.691 (0.609, 0.785)	0.823 (0.726, 0.933)	0.783 (0.683, 0.897)

Model 1: Adjusted for age, pre-pregnancy BMI, education, annual family income, ethnicity, parity, season of birth, region and particle with aerodynamic diameter less than 2.5 μm (PM_2.5)
Model 2: Adjusted for age, pre-pregnancy BMI, education, annual family income, ethnicity, parity, season of birth, region and nitrogen dioxide (NO₂)
Model 3: Adjusted for age, pre-pregnancy BMI, education, annual family income, ethnicity, parity, season of birth, region and ozone (O₃)