Table 3 Hazard ratios (HRs) for stillbirth given any nitrosatable prescription drug intake during the first 22 weeks of pregnancy by levels of maternal drinking water nitrate concentration
Household NO3- average (mg/L) | Any nitrosatable prescription drug intake during the first 22 weeks of pregnancy | No stillbirth | Stillbirth | HR (95% CI) | |
|---|---|---|---|---|---|
Unadjusted | Adjusteda | ||||
≤1 | No | 127,695 | 518 | 1 | 1 |
Yes | 23,738 | 98 | 1.03 (0.83–1.28) | 0.89 (0.61–1.30) | |
> 1- ≤ 2 | No | 170,289 | 581 | 1 | 1 |
Yes | 28,492 | 132 | 1.38 (1.14–1.67) | 1.55 (1.15–2.09) | |
> 2- ≤ 5 | No | 181,243 | 625 | 1 | 1 |
Yes | 33,377 | 124 | 1.10 (0.91–1.34) | 1.20 (0.87–1.66) | |
> 5- ≤ 25 | No | 52,442 | 192 | 1 | 1 |
Yes | 10,779 | 48 | 1.24 (0.91–1.70) | 1.32 (0.73–2.37) | |
> 25 | No | 18,904 | 77 | 1 | 1 |
Yes | 3440 | 16 | 1.17 (0.68–2.01) | 1.32 (0.60–2.90) | |