Table 4.
Estimated change in placental and umbilical cord blood mtDNA content in association with PM10 during pregnancy or distance from residence to nearest major road.
| Placental tissue (n = 174) | Umbilical cord blood (n = 176) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Variable | Percent change | 95% CI | p-Value | Percent change | 95% CI | p-Value | ||||||
| Time window (PM10)a,b | ||||||||||||
| Trimester 1 | –10.9 | –27.1, 8.9 | 0.26 | 11.2 | –6.0, 31.6 | 0.22 | ||||||
| Trimester 2 | –1.3 | –20.7, 22.9 | 0.91 | 1.8 | –14.2, 20.8 | 0.84 | ||||||
| Trimester 3 | –17.4 | –31.8, –0.1 | 0.05 | –5.8 | –20.0, 11.0 | 0.48 | ||||||
| Last month | –16.1 | –25.2, –6.0 | 0.003 | –3.6 | –12.3, 6.0 | 0.45 | ||||||
| Week (mean lag 0–7) | –10.1 | –17.6, –1.9 | 0.02 | –4.6 | –11.0, 2.2 | 0.20 | ||||||
| Traffic | ||||||||||||
| Distance from residence to a major roadb,c | 4.0 | 0.4, 7.8 | 0.03 | –2.0 | –4.8, 0.9 | 0.17 | ||||||
| aEffect size was estimated for each 10-µg/m3 increase in PM10 exposure at mother’s residence during the corresponding period. bAdjusted for newborn’s sex, maternal age (years), parity (continuous), gestational age (weeks), ethnicity (European/non-European), smoking status (never, before, current), season (cold/warm period), and time-specific apparent temperature (°C). Additionally, umbilical cord blood was adjusted for blood cell count (number of white blood cells, percent neutrophils, and number of platelets). cPercentage was calculated for each doubling in distance from residence to major road (based on a model with log distance and log mtDNA content). | ||||||||||||