Table 1.
Infant and maternal characteristics by gestational age at birth (1973–79)
|
Gestational age in weeks, % |
||||||
|---|---|---|---|---|---|---|
| 23–27 (N = 263) | 28–32 (N = 3367) | 33–34 (N = 5822) | 35–36 (N = 19 347) | 37–42 (N = 588 410) | ≥43 (N = 18 724) | |
| Infant’s gender | ||||||
| Male | 51.7 | 56.2 | 55.7 | 55.2 | 51.2 | 50.1 |
| Female | 48.3 | 43.8 | 44.3 | 44.8 | 48.8 | 49.9 |
| Maternal age at birth of child (years) | ||||||
| <18 | 2.3 | 3.3 | 2.9 | 2.3 | 1.4 | 1.9 |
| 18–24 | 38.0 | 36.8 | 35.8 | 35.3 | 34.9 | 41.4 |
| 25–34 | 50.6 | 51.5 | 52.9 | 54.3 | 57.7 | 53.2 |
| ≥35 | 9.1 | 8.4 | 8.4 | 8.1 | 6.0 | 3.6 |
| Maternal immigration status | ||||||
| Born in Sweden | 85.6 | 87.9 | 88.4 | 89.3 | 91.1 | 92.0 |
| Immigrated from Finland | 6.5 | 5.3 | 4.8 | 4.7 | 4.2 | 4.0 |
| Immigrated from another country | 8.0 | 6.8 | 6.8 | 5.9 | 4.7 | 4.1 |
| Maternal marital status in 1990 | ||||||
| Married/cohabiting | 68.2 | 69.7 | 70.3 | 72.0 | 76.4 | 72.9 |
| Never married | 15.9 | 13.6 | 12.8 | 11.7 | 9.5 | 11.5 |
| Divorced | 15.1 | 15.7 | 15.7 | 14.8 | 13.0 | 14.6 |
| Widowed | 0.8 | 1.0 | 1.2 | 1.5 | 1.2 | 1.0 |
| Maternal occupation in 1990 | ||||||
| Unskilled worker | 16.4 | 20.9 | 21.0 | 22.5 | 25.9 | 23.5 |
| Skilled worker | 17.1 | 16.2 | 15.9 | 16.7 | 18.2 | 17.4 |
| Professional | 7.6 | 9.3 | 8.9 | 9.3 | 9.4 | 9.6 |
| White collar | 27.4 | 29.3 | 30.1 | 29.1 | 27.4 | 28.8 |
| Other occupations | 11.8 | 9.4 | 9.2 | 9.0 | 8.5 | 9.1 |
| Unknown | 19.8 | 14.9 | 14.9 | 13.4 | 10.5 | 11.7 |
| Maternal income in 1990 | ||||||
| Lowest quartile | 36.5 | 28.7 | 27.7 | 26.1 | 23.0 | 24.2 |
| Second quartile | 20.5 | 25.3 | 24.8 | 25.8 | 25.7 | 25.3 |
| Third quartile | 24.7 | 24.6 | 24.7 | 25.0 | 25.7 | 25.8 |
| Highest quartile | 18.3 | 21.5 | 22.7 | 23.1 | 25.6 | 24.8 |
| Maternal education in 1990 (years) | ||||||
| Compulsory high school or less (≤9) | 36.1 | 31.4 | 32.1 | 30.9 | 26.9 | 29.5 |
| Practical high school or some theoretical high school (10–11) | 44.2 | 46.8 | 47.2 | 46.4 | 47.2 | 47.4 |
| Theoretical high school and/or college (≥12) | 19.8 | 21.8 | 20.7 | 22.7 | 25.9 | 23.1 |
| Paternal education in 1990 (years) | ||||||
| Compulsory high school or less (≤9) | 33.7 | 34.2 | 36.0 | 35.0 | 32.5 | 34.3 |
| Practical high school or some theoretical high school (10–11) | 45.8 | 44.3 | 43.6 | 43.5 | 43.5 | 44.5 |
| Theoretical high school and/or college (≥12) | 20.5 | 21.5 | 20.4 | 21.5 | 24.1 | 21.2 |
| Maternal region of residence in 1990 | ||||||
| Large city | 32.3 | 30.5 | 29.4 | 29.7 | 29.1 | 29.9 |
| Medium city | 34.6 | 35.1 | 38.2 | 37.3 | 36.9 | 37.3 |
| Small city or rural area | 33.1 | 34.3 | 32.4 | 33.0 | 34.0 | 32.8 |
| Maternal time lived at current residence as of 1990 (years) | ||||||
| <5 | 25.2 | 24.3 | 24.9 | 23.5 | 21.2 | 23.7 |
| ≥5 | 74.8 | 75.7 | 75.1 | 76.5 | 78.8 | 76.3 |
| Maternal prescription of psychotropic medications from 1 July 2005 through 31 December 2006 | ||||||
| Antidepressants | 12.9 | 13.2 | 11.9 | 13.3 | 12.4 | 12.9 |
| Antipsychotics | 2.3 | 2.5 | 2.0 | 2.3 | 1.7 | 1.6 |
| Anxiolytics | 9.5 | 7.7 | 7.6 | 8.1 | 6.8 | 7.0 |
| Hypnotics/sedatives | 14.1 | 14.3 | 12.5 | 13.1 | 12.1 | 12.6 |
| Psychostimulants | 0.0 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Any of the above | 24.3 | 24.4 | 22.5 | 24.4 | 22.4 | 23.0 |
| Maternal hospitalization for a mental disorder from 1 January 1964 through 31 December 2006 | 11.0 | 11.6 | 10.3 | 9.6 | 7.1 | 8.4 |