Table 5.
Estimates of the effects of the NO2 and O3 and significant control variables on placental flow index (n = 229).
| Placental variable/ pollutant and SV | Log FI | |||
|---|---|---|---|---|
| SB | p-Value | SB | 95% CI | |
| Model 1a (n = 228) | ||||
| NO2 | –0.001 | 0.991 | –6 × 10–6 | –0.001, 0.001 |
| O3 | –0.096 | 0.154 | –0.012 | –0.030, 0.005 |
| Model 2b (n = 228) | ||||
| NO2 | 0.006 | 0.927 | 4.9 × 10–5 | –0.001, 0.001 |
| O3 | –0.079 | 0.197 | –0.010 | –0.026, 0.005 |
| BMI | –0.430 | < 0.001 | –0.011 | –0.015, –0.008 |
| Parity | 0.135 | 0.037 | 0.040 | 0.002, 0.078 |
| Model 3c (n = 222) | ||||
| NO2 | 0.011 | 0.858 | 9.7 × 10–5 | –0.001, 0.001 |
| O3 | –0.073 | 0.246 | –0.009 | –0.026, 0.007 |
| BMI | –0.427 | < 0.001 | –0.011 | –0.015, –0.008 |
| Parity | 0.190 | 0.011 | 0.057 | 0.013, 0.101 |
| Model 4d (n = 187) | ||||
| NO2 | 0.008 | 0.907 | 7 × 10–5 | –0.001, 0.001 |
| O3 | –0.090 | 0.185 | –0.012 | –0.029, 0.006 |
| BMI | –0.432 | < 0.001 | –0.012 | –0.016, –0.009 |
| Parity | 0.209 | 0.007 | 0.065 | 0.018, 0.112 |
| Note: BMI, body mass index; CI, confidence intervals; FI, flow index; Log, logarithm; NO2, nitrogen dioxide; O3, ozone; SB, standardized beta; SV, significant variable. 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. | ||||