Table 10.
Relations of cord-blood THg * and possible confounders to the PDI ** of BSID-II: Standardized regression coefficients (β) of multiple regression analysis only in boys.
| Major Independent Variables | Urban Area (n = 220) | Coastal Area (n = 303) | ||
|---|---|---|---|---|
| β | p-Value | β | p-Value | |
| Cord-blood THg * | −0.033 | 0.606 | −0.18 | 0.002 |
| Birth weight | −0.045 | 0.477 | 0.091 | 0.128 |
| Birth order | −0.081 | 0.202 | 0.091 | 0.124 |
| Drinking habit during pregnancy | −0.058 | 0.362 | −0.044 | 0.450 |
| Smoking habit during pregnancy | −0.016 | 0.806 | 0.062 | 0.282 |
| Raven score *** | −0.098 | 0.126 | 0.124 | 0.033 |
| EES score at 18 months *** | 0.039 | 0.543 | 0.116 | 0.048 |
| Contribution rate, R2 | 0.148 | <0.001 | 0.052 | 0.007 |
Other independent variables: testers of the BSID-II and research area. Cord-blood THg was logarithmically transformed. * THg, total mercury. ** PDI, psychomotor developmental index. *** Raven, Raven standard progressive matrices; EES, Evaluation of Environmental Stimulation.