Table 1 Subject characteristics (mothers, n = 630; the youngest children, n = 916)
Items | n (%) | Mean (SD) | Range |
|---|---|---|---|
Maternal age (years; n = 629*) | 35.7 (4.9) | 23–51 | |
Number of children in the family | 2.2 (0.9) | 1–8 | |
Child age (years; n = 914*) | 3.6 (1.8) | 0–6 | |
Child sex (n = 869*) | |||
Boys | 463 (53.3) | ||
Girls | 406 (46.7) | ||
Child weight at birth (g) | 3005.7 (423.5) | 722–4320 | |
< 2500 | 89 (9.7) | 2201.7 (333.8) | 722–2498 |
≥2500 | 827 (90.3) | 3092.2 (331.1) | 2500–4320 |
Gestational age at birth (weeks; n = 884) | 38.7 (1.7) | 25–42 | |
Maternal age at birth (years; n = 909) | 31.2 (4.6) | 20–50 | |
Birth history | |||
Primipara | 347 (37.9) | ||
Multipara | 569 (62.1) | ||
Maternal weight gain during pregnancy (kg; n = 895) | 10.1 (3.7) | −4.0–27.0 | |
Maternal employment status during pregnancy | |||
Non-working | 397 (43.3) | ||
Working | 519 (56.7) | ||