Table 1.
Prenatal characteristics and IQ test scores of children at age 5 years and 8 years.
| Characteristics | Children at age 5 years (N = 120) Mean (SD) or n (%) | Children at age 8 years (N = 120) Mean (SD) or n (%) |
|---|---|---|
| Maternal Age | ||
| Age at enrollment (years), mean (SD) | 29.1 (4.4) | 29.1 (4.2) |
| Pre-pregnancy BMI (kg/m2), mean (SD) | 20.5 (2.8) | 20.5 (2.8) |
| Fish consumption (times/week), median (range) | 4.1 (0.1, 26.0) | 4.0 (0.1, 41.3) |
| Blood lead concentrations (μg/dL), mean (SD) | 2.6 (1.7) | 2.7 (1.6) |
| Previous live births, n (%) | ||
| 0 | 64 (54) | 59 (50) |
| ≥1 Education, n (%) |
54 (46) | 58 (50) |
| <High school | 2 (2) | 3 (3) |
| High school | 45 (38) | 44 (38) |
| Part college | 50 (42) | 46 (40) |
| ≥College | 21 (18) | 22 (19) |
| Annual family income (US $), n (%) | ||
| <20,000 | 49 (42) | 44 (39) |
| ≥20,000 | 67 (58) | 70 (61) |
| Smoking during pregnancy, n (%) | 1 (1) | 1 (1) |
| Drinking alcohol during pregnancy, n (%) | 0 | 0 |
| Children | ||
| Age (years), mean (SD) | 5.3 (0.3) | 8.2 (0.2) |
| HOME score, mean (SD) | 45.4 (5.2) | 46.0 (6.1) |
| IQ scores, mean (SD) | ||
| FSIQ | 105.8 (12.8) | 109.1 (11.4) |
| VIQ | 103.3 (12.7) | 110.1 (11.8) |
| PIQ | 106.9 (13.5) | 106.9 (12.0) |
| Sex, n (%) Male | 47 (52) | 45 (50) |
Abbreviation: BMI, body mass index; FSIQ, full scale intelligence quotient; HOME, Home Observation for Measurement of the Environment Inventory; PIQ, performance intelligence quotient; SD, standard deviation; VIQ, verbal intelligence quotient. There were missing values for maternal age (n = 2), pre-pregnancy BMI (n = 11); fish consumption (n = 7); blood lead concentrations (n = 9); previous live births (n = 1); education (n = 1); annual family income (n = 3); child HOME score at age 5 years (n = 1) and child sex (n = 28). There were missing values for maternal age (n = 4), pre-pregnancy BMI (n = 10); fish consumption (n = 7); blood lead concentrations (n = 10); previous live births (n = 1); education (n = 3); annual family income (n = 4); child HOME score at age 8 years (n = 8) and child sex (n = 28).