Table 1. Subject characteristics of 20 healthy infants born in the Netherlands.
| Category | Subcategory | Outcome |
| Sex | Male | 6 (30) |
| Female | 14 (70) | |
| Education mother | Primary and secondary school | 8 (40) |
| Some university or postsecondary education | 4 (20) | |
| Technical or trade qualification | 8 (40) | |
| Education father | Primary and secondary school | 6 (30) |
| Some university or postsecondary education | 5 (25) | |
| Technical or trade qualification | 9 (45) | |
| Delivery | Vaginal | 15 (75) |
| Caesarean | 5 (25) | |
| Feeding regimen | Formula feeding | 18 (90) |
| Breastfeeding | 2 (10) | |
| Twins | 4 (40) | |
| Birth weight, gram | 3135 (2560–5150) | |
| Gestational age, weeks | 39 (37–42) | |
| Age of the mother, years | 29.5 (19–37) |
- Categorical variables are presented as number (percentages).
- Numerical variables are presented as median (range).