Table 5.
Linear association of ln-transformed CO or PM2.5 exposure with newborn anthropometrics
| lnCO | lnPM2.5 | |||||
|---|---|---|---|---|---|---|
|
| ||||||
| β coefficient (95% CI) | p-value | Change in outcome per interquartile increasea in CO exposure (95% CI) | β coefficient (95% CI) | p-value | Change in outcome per interquartile increasea in PM2.5 exposure (95% CI) | |
|
| ||||||
| Birth weight (kg) | ||||||
| Unadjusted | − 0.01 (−0.11, 0.13) | 0.85 | − 0.01 kg (−0.09, 0.10) | − 0.21 (−0.46, 0.05) | 0.10 | −0.12 grams (−0.26, 0.03) |
| Adjustedb | − 0.02 (−0.14, 0.10) | 0.72 | −0.02 kg (−0.11, 0.08) | − 0.27 (−0.54, 0.00) | 0.05 | −0.15 grams (−0.30, 0.00) |
| Birth length (cm) | ||||||
| Unadjusted | 0.22 (−0.59, 1.03) | 0.59 | 0.17 cm (−0.46, 0.81) | − 1.89 (−4.02, 0.24) | 0.08 | −1.06 cm (−4.02, 0.13) |
| Adjustedb | − 0.03 (−0.88, 0.80) | 0.93 | −0.02 cm (−0.69, 0.63) | − 2.02 (−4.55, 0.52) | 0.11 | −1.13 cm (−2.55, 0.29) |
| Head circumference (cm) | ||||||
| Unadjusted | 0.07 (−0.32, 0.46) | 0.72 | 0.06 cm (−0.25, 0.36) | 0.24 (−0.78, 1.27) | 0.64 | 0.13 cm (−0.44, 0.71) |
| Adjustedb | − 0.02 (−0.04, 0.39) | 0.93 | −0.02 cm (−0.03, 0.31) | 0.26 (−0.95, 1.48) | 0.66 | 0.15 cm (−0.53, 0.83) |
CI= confidence interval. cm= centimeter. CO =carbon monoxide. kg=kilograms. PM2.5= fine particulate matter < 2.5 micrometers in diameter.
a
Interquartile change in exposure represents change from 25th to 75th centile of exposure. For CO, the interquartile range was 1.7 ppm and for PM2.5 this was 23.0 μg/m3. The effect size has been translated to a nonlogarithmic scale for ease of interpretation.
b
Adjusted for age, parity, sex of infant, compliance with prenatal vitamins, household asset index, body mass index, urban neighborhood, housing (single family home versus apartment/multifamily home), parent trial and year of measurements.