Family, infant and housing characteristics, divided by number of children (n = 1439).

1High educational level: at least higher professional education.2Intermediate educational level: senior secondary vocational education, senior general secondary education and university preparatory education.3Low educational level: preparatory secondary vocational education or less.4Differences in characteristics of first-time parents and non-first-time parents evaluated by chi-square test or Mann-Whitney U-test:*Significant at the 0.05 level,** significant at the 0.01 level,***significant at the 0.001 level.