Table 1.
Cohort details:
| N‡ | ||
|---|---|---|
|
| ||
| Maternal background | ||
| Ethnicity, N(%) | ||
| European | 323 (53.65) | |
| Maori | 602 | 217 (36.04) |
| Pacific | 32 (5.31) | |
| Other | 30 (4.98) | |
|
| ||
| Household income categories, N(%) | ||
| < NZD 10,000 | 13 (2.83) | |
| > NZD 10,000 – 20,000 | 50 (10.91) | |
| > NZD 20,000 – 30,000 | 66 (14.41) | |
| > NZD 30,000 – 40,000 | 458 | 59 (12.88) |
| > NZD 40,000 – 50,000 | 13 (2.83) | |
| > NZD 50,000 | 257 (56.11) | |
|
| ||
| Maternal substance use, N(%) | ||
| alcohol | 521 | 137 (26.29) |
| marijuana | 527 | 79 (14.99) |
| tobacco | 475 | 221 (46.52) |
| methamphetamine and other drugs | 528 | 79 (14.96) |
|
| ||
| Child characteristics | ||
|
| ||
| Gender female, N(%) | 606 | 287 (47.35) |
|
| ||
| Gestational age in weeks, mean (SD) | 600 | 38.8 (2.42) |
|
| ||
| Birth weight in kg, mean (SD) | 600 | 3.2 (0.73) |
|
| ||
| Preterm (>32 weeks’ gestation), N(%) | 600 | 156 (26) |
|
| ||
| Small (< 2.5 Kg birth weight), N(%) | 600 | 71 (11.83) |
|
| ||
| Large (> 4.5 Kg birth weight), N(%) | 600 | 41 (6.83) |
|
| ||
| Verbal IQ¶, N(%) | ||
| ≥85 | 600 | 430 (70.95) |
| <85 | 170 (28.05) | |
‡
N: the number of children for whom data were available. Not all study participants provided responses in all categories.
¶
Verbal IQ – verbal intelligence quotient.