Table 1 Population characteristics (data only from the consent group, n = 1721)

 Male / female

53,5% / 46,5%

 Place in family order:

  first child

41,7%

  second child

36,7%

  third child

13,8%

  four or younger child

7,8% (max 12 children )

Family characteristics:

 2-parent household

92,5%

 1-parent household

3,1%

 shared household

2,7%

 other (foster-family / adoption /  divorcement /living with  grandparents)

1,7%

Parent characteristics:

 age mother (mean in year, sd)

30,5 (sd 4,8)

 mother aged < 20 yr at birth of  this toddler

0,7% (n = 13)

 age father (mean in year, sd)

 father aged < 20 yr at birth of this  toddler

0,3% (n = 6)

 Ethnicity: non-Dutch mother

8,7%

 Ethnicity: non-Dutch father

7,8%

 Language: non-Dutch used at  home by mother

9,0%

 Language: non-Dutch used at  home by father

7,5%

 Education:

  Low education

19,4% mother (including 2,3% very low) 21, 2% father (including 1, 9% very low)

  Intermediate education

52,5% mother / 50,7% father

  High education

28,1% mother / 28,1% father

 Employment:

  Employed

72,7% mother / 92,9% father

  Unemployed

1,1% mother / 0,9% father

  Unemployable/unable to work

0,6% mother / 0,8% father

  Stay-at-home mother/father

25,3% mother/ 0,8% father