Table 1 Baseline characteristics of the study population

Mother’s age at birth (in years)

32 (29–34)

Mode of birth^a

  Vaginal

37 (52.9)

  Caesarian section

33 (47.1)

Child’s weight at birth (in g)^a

3382 (2965–3752)

Child’s height at birth (in cm)^a

52 (50–53)

Child’s age at nursery school entry (in months)^a

14 (13–17)

Child’s age at study entry (in months)

25 (18–30)

Number of siblings^a

  0

32 (50.8)

  1

26 (41.3)

  2

5 (7.9)

Highest education level of parents^a

  - Low (uncompleted education)

0 (0)

  - Middle (vocational training)

18 (26.5)

  - High (higher vocational training or university degree)

50 (73.5)