Table 1 Characteristics of the mothers (n = 534) and children (n = 597) participating in the study.
Characteristics (n = 597) | Median (IQR) | N (%) |
|---|---|---|
Maternal age at birth (years) | 31.8 (28.1, 35.3) | |
Maternal pre-pregnancy BMI (kg/m2) | 20.3 (18.8, 22.5) | |
Household income (10,000 yen/year) | 550 (420, 700) | |
Maternal education (years) | 14 (12, 16) | |
Gestational age (weeks) | 39.14 (38.14, 40.0) | |
Birthweight (g) | 2982 (2699, 3246) | |
Duration of breastfeeding (months) | 10 ( 4, 14 ) | |
Sex | ||
Boys | 310 (52) | |
Girls | 287 (48) | |
Parity | ||
Primiparous | 274 (46) | |
Multiparous | 323 (54) | |
Prenatal exposure to smoking | ||
Yes | 41 (7) | |
No | 556 (93) | |
