Table A3.
Mean birthweight (grams) by quartiles of perchlorate concentrations in male births from US born mothers in the study population of pregnant women from San Diego County 2000–2003 (p-trend in mean birthweights across quartiles=0.009)
| Perchlorate (µg/L)1 | N | Birthweight2 | 95% CI | p-value3 |
|---|---|---|---|---|
| 0.82–4.71 | 111 | 3402.5 | 3303.1–3502.0 | Reference |
| 4.72–6.89 | 111 | 3461.6 | 3362.7–3560.4 | 0.41 |
| 6.90–10.15 | 112 | 3563.6 | 3465.4–3661.8 | 0.02 |
| 10.25–86.83 | 111 | 3566.8 | 3467.8–3665.8 | 0.02 |
Abbreviations: CI, confidence interval; N, sample size
1
Unadjusted for urinary creatinine concentration
2
Adjusted means, adjusted for maternal age, maternal weight, urinary creatinine (log10), and race
3
p-value compared to the lowest quartile