Table 4

Perinatal outcome by socioeconomic group and by time, Finland, 1991–1999 (n=563952)*

Adjusted OR‡
1991–19931994–19961997–1999p†1991–19931994–19961997–1999
*All differences between the socioeconomic groups are statistically significant, p<0.001. See also table 3. †p Value for test for trend over time. ‡Adjusted by maternal age, parity, and county of residence. Singletons only.
Number199289190839175735193924185052169937
Prematurity, %
    Upper white collar workersI4.94.95.20.3521.001.001.00
    Lower white collar workersII5.15.15.30.5061.13 (1.06 to 1.21)1.16 (1.09 to 1.23)1.10 (1.03 to 1.17)
    Blue collar workersIII5.65.65.40.0121.32 (1.24 to 1.43)1.32 (1.24 to 1.43)1.16 (1.08 to 1.25)
    OthersO5.05.05.20.7781.27 (1.17 to 1.38)1.33 (1.24 to 1.43)1.25 (1.17 to 1.34)
Total5.15.15.30.469
Low birth weight, %
    Upper white collar workersI3.84.04.40.2061.001.001.00
    Lower white collar workersII3.94.24.40.0211.14 (1.05 to 1.24)1.21 (1.12 to 1.30)1.16 (1.08 to 1.24)
    Blue collar workersIII4.64.84.50.0031.49 (1.36 to 1.63)1.52 (1.40 to 1.66)1.25 (1.17 to 1.40)
    OthersO3.94.14.20.8361.36 (1.23 to 1.50)1.49 (1.37 to 1.62)1.37 (1.26 to 1.49)
Total4.04.24.40.126
SGA, %
    Upper white collar workersI2.12.12.20.6101.001.001.00
    Lower white collar workersII2.22.32.50.4241.14 (1.03 to 1.26)1.24 (1.13 to 1.37)1.19 (1.09 to 1.31)
    Blue collar workersIII2.82.72.80.2351.44 (1.30 to 1.63)1.69 (1.51 to 1.89)1.45 (1.34 to 1.66)
    OthersO2.22.22.40.8291.20 (1.07 to 1.36)1.59 (1.42 to 1.78)1.39 (1.25 to 1.55)
Total2.32.32.50.342
Perinatal mortality, 1/1000
    Upper white collar workersI5.75.45.60.2581.001.001.00
    Lower white collar workersII6.85.95.80.3331.38 (1.14 to 1.68)1.14 (0.95 to 1.37)1.08 (0.89 to 1.30)
    Blue collar workersIII8.37.16.80.7941.79 (1.44 to 2.21)1.50 (1.22 to 1.85)1.33 (1.07 to 1.66)
    OthersO9.08.66.50.0121.81 (1.46 to 2.26)1.57 (1.27 to 1.93)1.33 (1.08 to 1.64)
Total7.36.66.10.088
Birth weight, mean and SD, g
I3554576355058035245840.340
II3555587354359135245940.129
III3518605351460634995940.272
O3541603352560135055940.057
Total3545592353559435155920.169