Table 6.

Estimates of the effects of the NO₂ and O₃ and significant control variables on placental vascularization and flow index (n = 229).

Placental variable/ pollutant and SV	Log VFI
	SB	p-Value	SB	95% CI
Model 1a (n = 228)
NO2	–0.167	0.014	–0.008	–0.014, –0.002
O3	0.007	0.913	0.005	–0.086, 0.096
Model 2b (n = 228)
NO2	–0.151	0.024	–0.007	–0.013, –0.001
O3	–0.002	0.981	–0.001	–0.091, 0.089
BMI	0.185	0.006	0.026	0.008, 0.045
Model 3c (n = 222)
NO2	–0.136	0.048	–0.006	–0.012, –5.5 × 10–5
O3	–0.001	0.982	–0.001	–0.094, 0.092
BMI	0.196	0.005	0.028	0.009, 0.048
Model 4d (n = 187)
NO2	–0.211	0.004	–0.009	–0.016, –0.003
O3	0.037	0.601	0.025	–0.069, 0.118
Note: BMI, body mass index; CI, confidence intervals; Log, logarithm; NO2, nitrogen dioxide; O3, ozone; SB, standardized beta; SV, significant variable; VFI, vascularization and flow index. aModel 1: Exposure to both pollutants, controlling for gestational age of fetus. bModel 2: Exposure to both pollutants, controlling for gestational age of fetus, BMI, parity, smoking, and placental location. cModel 3: Exposure to both pollutants, controlling for gestational age of fetus, BMI, parity, smoking, placental location, maternal alcohol consumption, maternal age, maternal ethnicity, and maternal education level. dModel 4: Exposure to both pollutants, controlling for gestational age of fetus., BMI, parity, placental location, maternal alcohol consumption, maternal age, maternal ethnicity, and maternal education level.