Table 3.
Odds ratios (ORs) and 95% confidence intervals (CIs) for the association between exposure to PM2.5 and ozone over the first trimester (0–13 weeks of gestation) and placenta-mediated pregnancy complications.
| Quintile | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 (lowest) | 2 | 3 | 4 | 5 (highest) | Per IQR increase | |||||||
| Total PM2.5 (μg/m3) | ||||||||||||
| Median (IQR) | 14.0 (13.1–14.3) | 15.2 (14.9–15.5) | 16.1 (15.8–16.4) | 17.8 (17.5–18.5) | 21.3 (20.5–21.7) | |||||||
| No. of women | 16,616 | 16,736 | 16,678 | 16,714 | 16,710 | 83,454 | ||||||
| No. of outcome | 1669 | 1792 | 1761 | 1783 | 1658 | 8663 | ||||||
| OR (95% CI)a | Reference | 1.09 (1.01–1.18) | 1.11 (1.02–1.22) | 1.12 (1.01–1.25) | 1.07 (0.96–1.20) | 1.00 (0.94–1.05) | ||||||
| OR (95% CI)b | Reference | 1.09 (1.01–1.18) | 1.11 (1.02–1.22) | 1.13 (1.02–1.25) | 1.07 (0.96–1.19) | 0.99 (0.94–1.05) | ||||||
| PM2.5 components (μg/m3) | ||||||||||||
| Total carbon | ||||||||||||
| Median (IQR) | 3.2 (2.8–3.5) | 3.7 (3.7–3.8) | 4.1 (4.0–4.1) | 4.2 (4.2–4.3) | 4.6 (4.4–4.9) | |||||||
| No. of women | 13,508 | 13,492 | 13,584 | 13,569 | 13,553 | 67,706 | ||||||
| No. of outcome | 1403 | 1358 | 1433 | 1385 | 1479 | 7058 | ||||||
| OR (95% CI)a | Reference | 0.96 (0.87–1.06) | 1.10 (0.98–1.22) | 1.06 (0.95–1.18) | 1.11 (0.98–1.25) | 1.10 (1.04–1.17) | ||||||
| OR (95% CI)b | Reference | 0.96 (0.87–1.06) | 1.10 (0.98–1.23) | 1.06 (0.95–1.19) | 1.11 (0.98–1.26) | 1.10 (1.04–1.17) | ||||||
| OC | ||||||||||||
| Median (IQR) | 2.1 (1.8–2.3) | 2.4 (2.4–2.5) | 2.7 (2.7–2.8) | 2.9 (2.8–2.9) | 3.2 (3.0–3.3) | |||||||
| No. of women | 13,540 | 13,486 | 13,569 | 13,526 | 13,585 | 67,706 | ||||||
| No. of outcome | 1398 | 1351 | 1379 | 1402 | 1528 | 7058 | ||||||
| OR (95% CI)a | Reference | 0.97 (0.87–1.07) | 1.07 (0.97–1.19) | 1.10 (0.98–1.22) | 1.19 (1.05–1.34) | 1.14 (1.08–1.22) | ||||||
| OR (95% CI)b | Reference | 0.97 (0.87–1.07) | 1.08 (0.97–1.20) | 1.10 (0.99–1.23) | 1.20 (1.06–1.36) | 1.15 (1.08–1.22) | ||||||
| EC | ||||||||||||
| Median (IQR) | 1.1 (1.0–1.2) | 1.2 (1.2–1.3) | 1.3 (1.3–1.3) | 1.4 (1.4–1.4) | 1.5 (1.5–1.5) | |||||||
| No. of women | 13,483 | 13,549 | 13,543 | 13,547 | 13,584 | 67,706 | ||||||
| No. of outcome | 1440 | 1452 | 1373 | 1365 | 1428 | 7058 | ||||||
| OR (95% CI)a | Reference | 1.00 (0.91–1.11) | 0.91 (0.83–1.01) | 0.94 (0.86–1.04) | 0.99 (0.89–1.10) | 1.01 (0.96–1.07) | ||||||
| OR (95% CI)b | Reference | 1.00 (0.91–1.10) | 0.91 (0.82–1.00) | 0.94 (0.85–1.03) | 0.98 (0.89–1.09) | 1.01 (0.96–1.07) | ||||||
| Nitrate | ||||||||||||
| Median (IQR) | 0.3 (0.2–0.4) | 0.7 (0.6–0.8) | 1.3 (1.1–1.5) | 1.9 (1.8–2.1) | 2.6 (2.5–2.7) | |||||||
| No. of women | 13,502 | 13,547 | 13,537 | 13,539 | 13,581 | 67,706 | ||||||
| No. of outcome | 1416 | 1424 | 1424 | 1414 | 1380 | 7058 | ||||||
| OR (95% CI)a | Reference | 0.96 (0.88–1.05) | 1.01 (0.91–1.12) | 1.02 (0.91–1.15) | 1.02 (0.90–1.17) | 1.03 (0.95–1.13) | ||||||
| OR (95% CI)b | Reference | 0.96 (0.88–1.05) | 1.02 (0.92–1.13) | 1.03 (0.91–1.16) | 1.03 (0.90–1.17) | 1.03 (0.95–1.13) | ||||||
| Sulphate | ||||||||||||
| Median (IQR) | 1.7 (1.5–1.7) | 2.0 (1.9–2.1) | 2.8 (2.5–2.9) | 3.4 (3.2–3.6) | 4.1 (3.9–4.8) | |||||||
| No. of women | 13,528 | 13,481 | 13,547 | 13,584 | 13,566 | 67,706 | ||||||
| No. of outcome | 1442 | 1405 | 1380 | 1443 | 1388 | 7058 | ||||||
| OR (95% CI)a | Reference | 1.00 (0.91–1.11) | 1.01 (0.89–1.14) | 1.10 (0.96–1.25) | 1.10 (0.95–1.28) | 1.05 (0.97–1.13) | ||||||
| OR (95% CI)b | Reference | 1.00 (0.91–1.11) | 1.01 (0.89–1.15) | 1.10 (0.96–1.26) | 1.10 (0.95–1.28) | 1.05 (0.97–1.13) | ||||||
| Ammonium | ||||||||||||
| Median (IQR) | 1.0 (1.0–1.1) | 1.2 (1.2–1.3) | 1.5 (1.4–1.6) | 1.7 (1.7–1.7) | 1.8 (1.8–1.9) | |||||||
| No. of women | 13,452 | 13,536 | 13,558 | 13,611 | 13,549 | 67,706 | ||||||
| No. of outcome | 1447 | 1436 | 1417 | 1393 | 1365 | 7058 | ||||||
| OR (95% CI)a | Reference | 0.98 (0.90–1.06) | 1.02 (0.93–1.11) | 1.03 (0.93–1.15) | 1.03 (0.92–1.16) | 1.03 (0.95–1.12) | ||||||
| OR (95% CI)b | Reference | 0.98 (0.90–1.06) | 1.01 (0.93–1.11) | 1.03 (0.93–1.15) | 1.03 (0.92–1.16) | 1.03 (0.95–1.12) | ||||||
| Chloride | ||||||||||||
| Median (IQR) | 0.04 (0.03–0.06) | 0.09 (0.08–0.11) | 0.15 (0.14–0.18) | 0.30 (0.26–0.34) | 0.41 (0.39–0.44) | |||||||
| No. of women | 13,531 | 13,497 | 13,571 | 13,508 | 13,599 | 67,706 | ||||||
| No. of outcome | 1379 | 1404 | 1412 | 1441 | 1422 | 7058 | ||||||
| OR (95% CI)a | Reference | 1.00 (0.92–1.09) | 1.06 (0.96–1.17) | 1.16 (1.01–1.33) | 1.11 (0.96–1.29) | 1.04 (0.95–1.14) | ||||||
| OR (95% CI)b | Reference | 1.00 (0.92–1.09) | 1.06 (0.97–1.17) | 1.16 (1.01–1.33) | 1.11 (0.96–1.28) | 1.04 (0.95–1.14) | ||||||
| Sodium | ||||||||||||
| Median (IQR) | 0.10 (0.09–0.10) | 0.13 (0.12–0.13) | 0.15 (0.15–0.16) | 0.17 (0.16–0.17) | 0.19 (0.18–0.19) | |||||||
| No. of women | 13,516 | 13,546 | 13,561 | 13,499 | 13,584 | 67,706 | ||||||
| No. of outcome | 1388 | 1391 | 1415 | 1365 | 1499 | 7058 | ||||||
| OR (95% CI)a | Reference | 1.02 (0.94–1.10) | 1.08 (0.98–1.18) | 1.02 (0.92–1.14) | 1.15 (1.02–1.29) | 1.10 (1.03–1.18) | ||||||
| OR (95% CI)b | Reference | 1.02 (0.94–1.11) | 1.08 (0.98–1.19) | 1.03 (0.93–1.15) | 1.16 (1.03–1.31) | 1.11 (1.03–1.18) | ||||||
| Potassium | ||||||||||||
| Median (IQR) | 0.06 (0.05–0.06) | 0.06 (0.06–0.06) | 0.07 (0.06–0.07) | 0.08 (0.07–0.08) | 0.09 (0.09–0.10) | |||||||
| No. of women | 13,483 | 13,590 | 13,510 | 13,473 | 13,650 | 67,706 | ||||||
| No. of outcome | 1409 | 1354 | 1404 | 1425 | 1466 | 7058 | ||||||
| OR (95% CI)a | Reference | 0.95 (0.88–1.04) | 0.99 (0.91–1.08) | 1.04 (0.95–1.14) | 1.03 (0.94–1.12) | 1.05 (1.00–1.09) | ||||||
| OR (95% CI)b | Reference | 0.95 (0.88–1.03) | 0.98 (0.90–1.07) | 1.04 (0.95–1.13) | 1.03 (0.94–1.12) | 1.05 (1.00–1.09) | ||||||
| Calcium | ||||||||||||
| Median (IQR) | 0.05 (0.04–0.05) | 0.06 (0.06–0.07) | 0.07 (0.07–0.07) | 0.09 (0.08–0.09) | 0.11 (0.10–0.11) | |||||||
| No. of women | 13,507 | 13,574 | 13,496 | 13,539 | 13,590 | 67,706 | ||||||
| No. of outcome | 1411 | 1389 | 1490 | 1407 | 1361 | 7058 | ||||||
| OR (95% CI)a | Reference | 0.96 (0.88–1.04) | 1.04 (0.95–1.13) | 1.02 (0.93–1.12) | 1.02 (0.92–1.13) | 1.02 (0.97–1.07) | ||||||
| OR (95% CI)b | Reference | 0.95 (0.87–1.04) | 1.04 (0.96–1.13) | 1.02 (0.93–1.12) | 1.02 (0.92–1.13) | 1.01 (0.97–1.07) | ||||||
| Ozone (ppb) | ||||||||||||
| Median (IQR) | 25.8 (25.0–26.5) | 30.3 (28.8–31.4) | 33.8 (32.9–36.0) | 40.4 (38.5–42.1) | 45.4 (44.1–47.8) | |||||||
| No. of women | 16,669 | 16,700 | 16,670 | 16,707 | 16,708 | 83,454 | ||||||
| No. of outcome | 1731 | 1732 | 1746 | 1716 | 1738 | 8663 | ||||||
| OR (95% CI)a | Reference | 1.02 (0.93–1.13) | 1.04 (0.92–1.17) | 1.08 (0.96–1.23) | 1.12 (0.98–1.28) | 1.05 (0.97–1.14) | ||||||
| OR (95% CI)b | Reference | 1.02 (0.93–1.13) | 1.04 (0.92–1.18) | 1.09 (0.96–1.23) | 1.12 (0.98–1.28) | 1.05 (0.97–1.14) | ||||||
EC elemental carbon, IQR interquartile range, OC organic carbon.
aAdjusted for maternal age, birth year, season of conception.
bAdditionally adjusted for smoking, alcohol drinking, prepregnancy body mass index, current history of diabetes/gestational diabetes, infertility treatment and parity.