Table 1. Demographic characteristic of mother-infant pairs (n = 545).
| Characteristic | All subjects(n = 545) | Taiwan-born(n = 398) | Foreign-born(n = 147) | P value |
| Age (years) | 33.6(29.0–38.2) | 34.5(30.2–38.8) | 31.3(26.6–36.0) | <.0001 |
| Maternal height (cm) | 162(156–168) | 163(156–170) | 158(153–164) | 0.005 |
| Pre-pregnant weight (kg) | 54(44–64) | 56(46–66) | 50(44–56) | <.0001 |
| pregnant weight (kg) | 68(59–78) | 69(58–80) | 65(58–72) | <.0001 |
| Gestation (weeks) | 38.7(37.3–40.1) | 38.6(37.1–40.1) | 38.9(37.6–40.2) | 0.01 |
| Head circumference (cm) | 33.4(32.1–34.8) | 33.3(32.0–34.6) | 33.5(31.8–35.2) | 0.24 |
| Baby’s height (cm) | 49.7(46.2–53.2) | 49.6(45.6–53.6) | 50.0(47.3–52.7) | 0.74 |
| Baby’s birth weight (g) | 3147(2685–3609) | 3135(2687–3585) | 3179(2680–3678) | 0.03 |
| Sex of newborn baby | 0.88 | |||
| Male | 274(50.6) | 202(50.8) | 72(50) | |
| Female | 268(49.4) | 196(49.2) | 72(50) | |
| Parity | 0.46 | |||
| ≤1 | 318(58.3) | 236(59.3) | 82(55.8) | |
| ≥2 | 227(41.7) | 162(40.7) | 65(44.2) | |
| Occupational exposure | 0.1 | |||
| Yes | 52(9.5) | 43(10.8) | 9(6.1) | |
| No | 493(90.5) | 355(89.2) | 138(93.9) | |
| Amalgam fillings during pregnancy | 0.58 | |||
| Yes | 17(3.2) | 14(3.6) | 3(2.1) | |
| No | 514(96.8) | 373(96.4) | 141(97.9) | |
| Smoking during pregnancy | 0.11 | |||
| Yes | 8(1.5) | 8(2.1) | 0(0) | |
| No | 516(98.5) | 371(97.9) | 145(100) | |
| Alcohol consumption | 0.33 | |||
| Yes | 111(34.7) | 65(32.7) | 46(38) | |
| No | 209(65.3) | 134(67.3) | 75(62) | |
| Consumed traditional Chinese herbs | 0.01 | |||
| Yes | 89(16.3) | 75(18.8) | 14(9.5) | |
| No | 456(83.7) | 323(81.2) | 133(90.5) | |
| Fish cutlet consumption | 0.1 | |||
| <1 meal/week | 142(31) | 111(32.6) | 31(26.5) | |
| 1–2 meals/week | 197(43) | 150(44) | 47(40.2) | |
| ≥3 meals/week | 119(26) | 80(23.4) | 39(33.3) | |
| Sashimi consumption | 0.38 | |||
| <1 meal/week | 223(94.9) | 182(95.8) | 41(91) | |
| 1–2 meals/week | 11(4.7) | 7(3.7) | 4(9) | |
| ≥3 meals/week | 1(0.4) | 1(0.5) | 0(0) |