Table 1 Basic characteristics of parents and their children
Characteristics | Normal (n = 245) | Borderline/clinical (n = 213) | p value | |
|---|---|---|---|---|
Maternal age (years) | 31.5 ± 4.3 | 29.8 ± 4.8 | < 0.001 | |
Paternal age (years) | 33.4 ± 5.5 | 31.3 ± 5.1 | < 0.001 | |
Maternal pre-pregnancy BMI (kg/m2) | 20.7 ± 2.5 | 21.4 ± 3.3 | 0.020 | |
0.02 maternal cotinine levels at third trimester (ng/ml) | ≦ 0.21 (non-smoker) | 151 (61.6) | 97 (45.5) | < 0.001 |
0.22–11.47 (passive smoker) | 81 (33.1) | 93 (43.7) | ||
≧ 11.48 (active smoker) | 13 (5.3) | 23 (10.8) | ||
Maternal education (years) | ≦ 12 | 88 (35.9) | 92 (43.2) | 0.107 |
≧ 13 | 154 (62.8) | 118 (55.4) | ||
Missing | 3 (1.2) | 3 (1.4) | ||
Paternal education (years) | ≦ 12 | 89 (36.3) | 86 (40.4) | 0.326 |
≧ 13 | 154 (62.9) | 123 (57.7) | ||
Missing | 2 (0.8) | 4 (1.9) | ||
Family income during pregnancy (JPY) | < 5 M | 125 (51.0) | 133 (62.4) | 0.001 |
≧ 5 M | 90 (36.7) | 48 (22.5) | ||
Missing | 30 (12.2) | 32 (15.0) | ||
Family income at SDQ completed (JPY) | < 5 M | 111 (45.3) | 111 (52.1) | 0.008 |
≧ 5 M | 123 (50.2) | 88 (41.3) | ||
Missing | 11 (4.5) | 14 (6.6) | ||
Marital Status at SDQ completed | Married | 236 (96.3) | 198 (93.0) | 0.116 |
Gestational age (days) | 275.3 ± 8.2 | 275.4 ± 8.5 | 0.897 | |
Birth weight (g) | 3037 ± 339 | 3076 ± 383 | 0.240 | |
Child sex | Boy | 122 (49.8) | 128 (60.1) | 0.027 |
Girl | 123 (50.2) | 85 (39.9) | ||
Birth order | First child | 116 (47.3) | 123 (57.7) | 0.026 |
Age at SDQ completed (months) | 67.3 ± 6.2 | 66.3 ± 6.3 | 0.099 | |