Table 2.
Association between time-varying cumulative average and prior week exposure to nitrogen dioxide (NO2), ozone (O3), particulate matter <2.5 μm (PM2.5) and black carbon (BC) exposure and time to pregnancy loss (n=275 women, 345 ART pregnancies) among women in the Environment and Reproductive Health (EARTH) Study (2005-2015).
| Adjusted HR (95% CI) per IQR Increasea | |||
|---|---|---|---|
| Main Effect | <30 days | ≥30 days | |
| Number of Events/Pregnancies at Risk | 99/345 | 74/345 | 25/271 |
| Cumulative average exposure | |||
| NO2 | 1.07 (0.87, 1.32) | 0.83 (0.57, 1.20) | 1.34 (1.13, 1.58) |
| O3 | 0.98 (0.90, 1.06) | 0.99 (0.91, 1.08) | 0.93 (0.81, 1.06) |
| PM2.5 | 0.80 (0.51, 1.27) | 0.86 (0.53, 1.39) | 0.62 (0.24, 1.58) |
| BC | 0.78 (0.52, 1.17) | 0.72 (0.45, 1.17) | 0.93 (0.56, 1.55) |
| Exposure in prior week | |||
| NO2 | 0.98 (0.85, 1.14) | 0.89 (0.69, 1.15) | 1.05 (0.92, 1.20) |
| O3 | 0.98 (0.91, 1.06) | 1.00 (0.92, 1.08) | 0.92 (0.76, 1.11) |
| PM2.5 | 0.92 (0.78, 1.08) | 0.95 (0.80, 1.14) | 0.82 (0.61, 1.10) |
| BC | 0.90 (0.69, 1.17) | 0.89 (0.65, 1.23) | 0.92 (0.65, 1.31) |
Note: BC, black carbon; NO2, nitrogen dioxide; O3, ozone; PM2.5, particulate matter <2.5 μm.
a
Models were adjusted for age, BMI, smoking status, race, education, current employment, and protocol. An IQR increase was 18 ppb for NO2, 12 ppb for O3, 2 μg/m3 for PM2.5, and 0.2 μg/m3 for BC.