TABLE 2.
Unadjusted associations between selected characteristics and inorganic dietary arsenic consumption among National Birth Defects Prevention Study control mothers, 1997–2011
| Inorganic arsenic (μg/day) |
||||||||
|---|---|---|---|---|---|---|---|---|
| Low (<3.2) (N = 3,629) |
Medium (3.2–5.5) (N = 3,629) |
High (≥5.5) (N =3,628) |
Medium versus low |
High versus low |
||||
| Maternal characteristic | N | (%) | N | (%) | N | (%) | OR (95% CI) | OR (95% CI) |
| Age (years)a | ||||||||
| <20 | 481 | 13.3 | 254 | 7.0 | 300 | 8.3 | 0.5 (0.4, 0.6) | 0.6 (0.5, 0.7) |
| 20–24 | 930 | 25.6 | 714 | 19.7 | 772 | 21.3 | 0.7 (0.6, 0.8) | 0.8 (0.7, 0.9) |
| 25–29 | 995 | 27.4 | 1,065 | 29.4 | 993 | 27.4 | Referent | Referent |
| 30–34 | 815 | 22.5 | 1,050 | 28.9 | 970 | 26.7 | 1.2 (1.1, 1.4) | 1.2 (1.0, 1.4) |
| 35–39 | 332 | 9.2 | 470 | 13.0 | 489 | 13.5 | 1.3 (1.1, 1.6) | 1.5 (1.3, 1.7) |
| ≥40 | 76 | 2.1 | 76 | 2.1 | 104 | 2.9 | 0.9 (0.7, 1.3) | 1.4 (1.0, 1.9) |
| Education (years)a | ||||||||
| 0–8 | 155 | 4.3 | 179 | 5.0 | 204 | 5.7 | 1.5 (1.2, 2.0) | 1.7 (1.4, 2.2) |
| 9–11 | 467 | 13.0 | 330 | 9.2 | 432 | 12.0 | 0.9 (0.8, 1.1) | 1.2 (1.0, 1.4) |
| 12 | 1,007 | 28 | 754 | 20.9 | 771 | 21.4 | Referent | Referent |
| 13–15 | 1,034 | 28.8 | 994 | 27.6 | 883 | 24.5 | 1.3 (1.1, 1.5) | 1.1 (1.0, 1.3) |
| ≥16 | 934 | 26.0 | 1,346 | 37.4 | 1,317 | 36.5 | 1.9 (1.7, 2.2) | 1.8 (1.6, 2.1) |
| Race/ethnicity | ||||||||
| Non-Hispanic White | 2,304 | 63.5 | 2,333 | 64.3 | 1,777 | 49.0 | Referent | Referent |
| Non-Hispanic Black | 461 | 12.7 | 339 | 9.3 | 354 | 9.8 | 0.7 (0.6, 0.8) | 1.0 (0.9, 1.2) |
| Hispanic | 701 | 19.3 | 794 | 21.9 | 1,118 | 30.8 | 1.1 (1.0, 1.3) | 2.1 (1.8, 2.3) |
| Other | 161 | 4.4 | 163 | 4.5 | 377 | 10.4 | 1.0 (0.8, 1.3) | 3.0 (2.5, 3.7) |
| Pre-pregnancy BMI (kg/m2) | ||||||||
| <18.5 | 193 | 5.5 | 155 | 4.5 | 208 | 6.0 | 0.8 (0.6, 1.0) | 1.0 (0.8, 1.3) |
| 18.5–24.9 | 1,823 | 51.9 | 1,859 | 53.4 | 1,913 | 55.5 | Referent | Referent |
| 25–30.0 | 796 | 22.7 | 841 | 24.2 | 753 | 21.8 | 1.0 (0.9, 1.2) | 0.9 (0.8, 1.0) |
| ≥30.0 | 701 | 20 | 628 | 18 | 576 | 16.7 | 0.9 (0.8, 1.0) | 0.8 (0.7, 0.9) |
| NBDPS site | ||||||||
| Arkansas | 677 | 18.7 | 444 | 12.2 | 275 | 7.6 | 0.8 (0.7, 1.0) | 0.6 (0.5, 0.8) |
| California | 363 | 10.0 | 375 | 10.3 | 456 | 12.6 | 1.3 (1.1, 1.6) | 1.9 (1.6, 2.3) |
| Georgia | 310 | 8.5 | 376 | 10.4 | 375 | 10.3 | 1.5 (1.2, 1.8) | 1.8 (1.5, 2.3) |
| Iowa | 496 | 13.7 | 401 | 11.1 | 325 | 9.0 | Referent | Referent |
| Massachusetts | 274 | 7.6 | 450 | 12.4 | 556 | 15.3 | 2.0 (1.7, 2.5) | 3.1 (2.5, 3.8) |
| New Jersey | 110 | 3.0 | 175 | 4.8 | 269 | 7.4 | 2.0 (1.5, 2.6) | 3.7 (2.9, 4.9) |
| New York | 274 | 7.6 | 322 | 8.9 | 344 | 9.5 | 1.5 (1.2, 1.8) | 1.9 (1.6, 2.4) |
| North Carolina | 361 | 10.0 | 307 | 8.5 | 273 | 7.5 | 1.1 (0.9, 1.3) | 1.2 (0.9, 1.4) |
| Texas | 406 | 11.2 | 396 | 10.9 | 436 | 12.0 | 1.2 (1.0, 1.5) | 1.6 (1.3, 2.0) |
| Utah | 358 | 9.9 | 383 | 10.6 | 319 | 8.8 | 1.3 (1.1, 1.6) | 1.4 (1.1, 1.7) |
| Alcohol useb,c | ||||||||
| No drinking | 2,255 | 63.0 | 2,194 | 61.2 | 2,330 | 64.8 | Referent | Referent |
| Drinking with no binge episodes | 477 | 13.3 | 476 | 13.3 | 394 | 11.0 | 1.0 (0.9, 1.2) | 0.8 (0.7, 0.9) |
| Drinking and ≥1 binge episode | 849 | 23.7 | 915 | 25.5 | 874 | 24.3 | 1.1 (1.0, 1.2) | 1.0 (0.9, 1.1) |
| Cigarette smoke exposureb | ||||||||
| No active or passive smoking | 2,277 | 63.3 | 2,603 | 72.1 | 2,643 | 73.5 | Referent | Referent |
| Active smoking only | 328 | 9.1 | 264 | 7.3 | 227 | 6.3 | 0.7 (0.6, 0.8) | 0.6 (0.5, 0.7) |
| Passive smoking only | 509 | 14.2 | 398 | 11.0 | 433 | 12.0 | 0.7 (0.6, 0.8) | 0.7 (0.6, 0.8) |
| Active and passive smoking | 483 | 13.4 | 346 | 9.6 | 295 | 8.2 | 0.6 (0.5, 0.7) | 0.5 (0.5, 0.6) |
Abbreviations: BMI, body mass index; CI, confidence interval; NBDPS, National Birth Defects Prevention Study; OR, odds ratio.
a
At delivery.
b
During the period one month before conception through the third month of pregnancy.
c
Binge episode defined as 4 or more drinks in one sitting.