Table 3.
PM2.5 exposure during the different periods of pregnancy in association with placental mtDNA methylation and placental mtDNA content
| First trimester |
Second trimester |
Third trimester |
Entire pregnancy |
|||||
|---|---|---|---|---|---|---|---|---|
| Variable | β | (95% CI) | β | (95% CI) | β | (95% CI) | β | (95% CI) |
| mtDNA methylation* | ||||||||
| MT-RNR1, % | 1.27 | (0.23 to 2.32)† | 0.19 | (−0.80 to 1.16) | 1.04 | (−0.20 to 1.86) | 0.91 | (0.56 to 4.18)† |
| D-loop, %# | 0.44 | (0.12 to 0.75)† | 0.09 | (−0.22 to 0.39) | 0.04 | (−0.29 to 0.36) | 0.21 | (−0.003 to 1.02) |
| Combined, % | 0.75 | (0.16 to 1.34)† | 0.10 | (−0.47 to 0.65) | 0.46 | (−0.23 to 0.96) | 0.47 | (0.20 to 2.23)† |
| mtDNA content, %** | −7.57 | (−20.78 to 7.86) | −15.19 | (−28.34 to 0.38) | −23.58 | (−36.27 to −8.37)† | −15.60 | (−23.92 to −6.38)† |
*
β represents an absolute change in percentage methylation for an IQR increment of PM2.5 exposure (µg/m3).
**
β represents a relative change in placental mtDNA content for an IQR increment of PM2.5 exposure (µg/m3).
#
Data available for 356 individuals.
†
P-value significantly lower than 0.05. All models are adjusted for gender, age, gestational age, smoking, maternal education, parity, ethnicity, and season at conception.