Table 1.
Selected characteristics of 212 mothers and their infants in the National Children’s Study.
| Characteristic | Urinary dimethylarsinic acid (μg/L) | p-value | ||||
|---|---|---|---|---|---|---|
| All (N=212) | Q1 (≤1.93) (n=51) | Q2 (1.94–3.50) (n=55) | Q3 (3.51–5.72) (n=62) | Q4 (>5.72) (n=44) | ||
| Race/ethnicity | 0.26 | |||||
| Caucasian | 169 (79.7) | 43 (25.4) | 46 (27.2) | 48 (28.4) | 32 (18.9) | |
| African American | 11 (5.2) | -- | -- | -- | -- | |
| Other | 32 (15.1) | -- | -- | -- | -- | |
| Maternal age (year) (mean ± SD) | 28.58 (5.78) | 28.25 (6.69) | 28.45 (4.83) | 28.35 (5.85) | 29.43 (5.72) | 0.75 |
| Education level [n(%)] | 0.80 | |||||
| <High school | 21 (9.9) | -- | -- | -- | -- | |
| High school graduate | 99 (46.7) | 27 (27.3) | 23 (23.2) | 29 (29.3) | 20 (20.2) | |
| >High school | 92 (43.4) | 19 (20.7) | 28 (30.4) | 25 (27.2) | 20 (21.7) | |
| Family income [n(%)] | 0.13 | |||||
| ≤$29,999 | 55 (25.9) | 13 (23.6) | 14 (25.5) | 16 (29.1) | 12 (21.8) | |
| $30,000–$74,999 | 86 (40.6) | 23 (26.7) | 14 (16.3) | 30 (34.9) | 19 (22.1) | |
| ≥$75,000 | 71 (33.5) | -- | -- | -- | -- | |
| Number of previous live births [n(%)] | 0.25 | |||||
| 0 | 69 (32.6) | 21 (30.4) | 14 (20.3) | 16 (23.2) | 18 (26.1) | |
| 1 | 79 (37.3) | 17 (21.5) | 25 (31.7) | 26 (32.9) | 11 (13.9) | |
| ≥2 | 64 (30.2) | 13(20.3) | 16 (25.0) | 20 (31.3) | 15 (23.4) | |
| Pre-pregnancy BMI (kg/m2) (mean ± SD) | 25.80(6.49) | 26.58 (6.16) | 25.84 (6.81) | 25.69 (6.24) | 24.99 (6.93) | 0.70 |
| Urinary arsenic (fig/L) [median (IQR)] | ||||||
| Total arsenic (n=114) | 7.77 (7.98) | 2.63 (1.13) | 4.87 (4.35) | 9.12(3.16) | 16.10(17.96) | <0.0001 |
| Dimethylarsinic acid (DMA) | 3.44(3.13) | 1.20 (0.00) | 2.72 (0.85) | 4.38 (0.82) | 7.49 (2.63) | -- |
| Urinary creatinine (fig/L) [median (IQR)] | 94.77 (72.15) | 47.82 (36.56) | 92.22 (60.82) | 121.83 (76.67) | 129.93 (70.27) | <0.0001 |
| Pregnancy complication [n(%)] (n=208) | ||||||
| Any complication | 80 (38.46) | 23 (46.00) | 20 (37.04) | 22 (35.48) | 15 (35.71) | 0.66 |
| Gestational diabetes | 18(8.65) | -- | -- | -- | -- | 0.94 |
| Preeclampsia | 10(4.81) | - | - | - | - | 0.77 |
| Preterm birth | -- | -- | -- | -- | -- | 0.24 |
| Infant sex [n(%)] | 0.07 | |||||
| Male | 114 (53.8) | 30 (26.3) | 35 (30.7) | 25 (21.9) | 24 (21.1) | |
| Female | 98 (46.2) | 21 (21.4) | 20 (20.4) | 37 (37.8) | 20 (20.4) | |
| Infant birth outcomes | ||||||
| Gestational age (weeks) (mean ± SD) | 38.75 (1.41) | 38.55 (1.78) | 38.89 (1.36) | 38.90 (1.13) | 38.59 (1.35) | 0.41 |
| Birth weight (kg) (mean ± SD) | 3.38 (0.49) | 3.33 (0.46) | 3.47 (0.50) | 3.43 (0.51) | 3.28 (0.49) | 0.22 |
| Birth length (cm) (mean ± SD) | 50.06 (2.91) | 49.99 (3.23) | 50.17 (2.74) | 49.80 (2.66) | 50.38 (3.14) | 0.78 |
| Head circumference (cm) (mean ± SD) | 34.78 (1.65) | 34.51 (1.68) | 35.05 (1.71) | 34.75 (1.61) | 34.80 (1.59) | 0.43 |
| Ponderal index (kg/m3) (mean ± SD) | 27.05 (3.74) | 26.76 (3.59) | 27.50 (3.56) | 27.76 (3.39) | 25.85 (4.36) | 0.05 |
*
Chi-square test for categorical variables, ANOVA test for normally distributed continuous variables, and Kruskal-Wallis test for non-normal distributed continuous variables