Table 1 Characteristics of the first-time mothers and infants included in the study
Characteristic | N | (%) | Mean (Range) |
|---|---|---|---|
Age (years) | 413 |  | 28.8 (17–41) |
Sampling year | 413 | Â | Â |
   1996-1999 | 203 | (49%) |  |
   2000-2003 | 58 | (14%) |  |
   2004-2006 | 62 | (15%) |  |
   2008-2010 | 90 | (22%) |  |
Pre-pregnancy BMI (body mass index, kg/m2) | 412 | Â | 23.4 (15.9-39.7) |
Weight gain during pregnancy (%) | 411 |  | 23 ((−6)-54) |
Years of education | 389 | Â | Â |
   ≤ 4 years of high school | 138 | (35%) |  |
   1–3 years of higher education | 76 | (20%) |  |
   >3 years of higher education | 175 | (45%) |  |
Smoking habits during pregnancy | 411 | Â | Â |
   Smoker | 53 | (13%) |  |
   Non-smoker | 302 | (73%) |  |
   Former smoker | 56 | (14%) |  |
Consumption of fish (g/day) | 374 |  | 29 (0–134) |
Gestational length (days) | 295 |  | 281 (249–302) |
Birth weight of the child (g) | 411 |  | 3589 (2430–5110) |
Sex of the child | 411 | Â | Â |
   Male | 218 | (53%) |  |
   Female | 193 | (47%) |  |