Table 3.
Distribution of maternal and cord blood Hg concentration (μg/L) by maternal characteristics.
| Maternal blood Hg |
||||||
|---|---|---|---|---|---|---|
| During early pregnancy |
During late pregnancy |
Cord blood Hg |
||||
| Characteristic | Median | p-Valuea | Median | p-Valuea | Median | p-Valuea |
| Age (years) | ||||||
| < 30 | 3.96 | 0.85 | 3.20 | 0.13 | 5.62 | 0.26 |
| 30 to < 35 | 3.84 | 3.35 | 5.64 | |||
| ≥ 35 | 3.57 | 3.04 | 5.06 | |||
| BMI at prepregnancy (kg/m2) | ||||||
| < 18.5 | 3.54 | 0.66 | 3.83 | 0.28 | 6.03 | 0.50 |
| 18.5 to < 23.0 | 3.66 | 3.19 | 5.48 | |||
| ≥ 23.0 | 4.13 | 3.37 | 5.74 | |||
| Education (years) | ||||||
| < 12 | 3.66 | 0.27 | 3.09 | 0.04 | 5.01 | < 0.01 |
| ≥ 12 | 3.89 | 3.38 | 5.78 | |||
| Fish consumption (g/day) | ||||||
| ≤ 150 | 3.76 | 0.32 | 3.16 | 0.03 | 5.54 | 0.18 |
| > 150 | 4.27 | 3.95 | 5.75 | |||
|
GSTM1 | ||||||
| Present | 3.90 | 0.77 | 3.30 | 0.90 | 5.53 | 0.88 |
| Null | 3.69 | 3.21 | 5.58 | |||
|
GSTT1 | ||||||
| Present | 3.95 | 0.70 | 3.22 | 0.53 | 5.54 | 0.42 |
| Null | 3.67 | 3.26 | 5.56 | |||
a
p-Value calculated by the Wilcoxon rank sum test or Kruskal–Wallis rank sum test because of the skewness of the Hg data.