Descriptive statistics by paternal age, for siblings born between 1987 and 2000
| Paternal age in years | LBW (%) | Preterm (%) | Birth year 1987–1990 | Birth year 1991–1994 | Birth year 1995–2000 | Birth order (mean) | Household income decile (mean) | Mother smoked during pregnancy (%) | Household high education (%) | Maternal age (mean) | n | % |
| ≤24 | 2.9 | 4.0 | 35.6 | 33.8 | 30.6 | 1.4 | 3.7 | 23.6 | 17.8 | 22.2 | 10 774 | 10.1 |
| 25–29 | 2.0 | 3.5 | 31.2 | 36.0 | 32.8 | 1.7 | 5.2 | 12.8 | 37.0 | 26.2 | 34 526 | 32.4 |
| 30–34 | 1.9 | 3.3 | 21.9 | 35.1 | 43.1 | 2.0 | 6.0 | 10.3 | 40.5 | 29.6 | 36 320 | 34.1 |
| 35–39 | 2.2 | 3.7 | 16.5 | 31.6 | 52.0 | 2.4 | 6.1 | 9.7 | 39.3 | 32.7 | 17 571 | 16.5 |
| ≥40 | 2.8 | 4.5 | 15.5 | 30.0 | 54.5 | 2.5 | 6.0 | 11.2 | 35.7 | 35.1 | 7461 | 7.0 |
| Average | 2.2 | 3.6 | 24.9 | 34.3 | 40.8 | 1.9 | 5.5 | 12.4 | 36.6 | 28.6 | 106 652 |
LBW, low birth weight.