Table 1.
Characteristics of the study population (n = 562).
| Characteristic | n | Percent |
|---|---|---|
| Child’s sex | ||
| Male | 286 | 50.9 |
| Female | 276 | 49.1 |
| Season of conception | ||
| Spring | 156 | 27.8 |
| Summer | 165 | 29.4 |
| Fall | 129 | 23.0 |
| Winter | 112 | 19.9 |
| Smoking during pregnancy | ||
| Never | 231 | 42.0 |
| Former, quit before pregnancy | 144 | 26.2 |
| Former, quit during pregnancy | 84 | 15.3 |
| Current | 91 | 16.6 |
| Passive smoking (reference: no) | ||
| At home | 197 | 35.8 |
| At work | 149 | 27.0 |
| Either at home or at work | 296 | 53.7 |
| Maternal education | ||
| Primary education | 164 | 29.3 |
| Secondary education | 233 | 41.7 |
| University degree | 162 | 29.0 |
| Maternal race/ethnicity | ||
| White/Caucasian | 543 | 96.8 |
| Latin American | 14 | 2.5 |
| Black | 4 | 0.7 |
| Child birth order | ||
| First | 317 | 56.6 |
| Second | 206 | 36.8 |
| Third or more | 37 | 6.6 |
| Continuous variable | Mean ± SD | Range |
| Maternal age (years) | 31.0 ± 4.3 | 17–43 |
| Gestational age (weeks) | 39.7 ± 1.4 | 34–42 |
| Maternal height (cm) | 162.4 ± 6.1 | 146–180 |
| Maternal prepregnancy weight (kg) | 62.6 ± 12.8 | 39–143 |
| Paternal height (cm) | 175.9 ± 7.1 | 150–197 |
| Paternal weight (kg) | 80.2 ± 12.5 | 50–130 |
| Birth weight (g) | 3247.4 ± 423.4 | 1,750–4,480 |
| Birth height (cm) | 49.4 ± 1.9 | 44–55 |
| Birth HC (cm) | 34.2 ± 1.2 | 30–38 |
| Birth AC (cm) | 31.3 ± 2.0 | 25–37 |