Father | Mother | Son | Daughter | |
Birth weight (g) | ||||
Mean value | 3 581 | 3 429 | 3 555 | 3 452 |
Standard deviation | 531 | 504 | 580 | 540 |
Per cent of births with low birth weight | 2.6 | 3.3 | 4.0 | 3.9 |
Age at childbirth (y) | ||||
Mean value | 24.7 | 23.1 | ||
Standard deviation | 3.0 | 3.1 | ||
Year of birth, number of subjects | ||||
1967–69 | 34 237 | 18 509 | ||
1970–72 | 21 864 | 25 095 | ||
1973–75 | 9 110 | 16 315 | ||
1976–78 | 2 294 | 6 663 | ||
1979–81 | 286 | 1 195 | ||
1982–84 | 4 | 18 | 3 | 2 |
1985–87 | 369 | 295 | ||
1988–90 | 2 666 | 2 517 | ||
1991–93 | 7 395 | 6 775 | ||
1994–96 | 13 671 | 12 815 | ||
1997–98 | 10 944 | 10 343 |