Trends in socioeconomic differences in Finnish perinatal health 1991-2006

Background: Socioeconomic differences in perinatal health decreased in Finland in the late 1990s. Whether the decreasing socioeconomic differences in perinatal health observed in Finland in the late 1990s have continued in 2000-6 was studied. Methods: The data were based on 965 443 births and 931 285 singletons recorded between 1991 and 2006 in the Finnish Medical Birth Register. Information on socioeconomic position was based on maternal occupation. Perinatal health was measured with six different indicators. Results: The proportions of preterm, low birthweight and SGA (small-for-gestational-age) births remained stable during the study period, but decreased for LGA (large-for-gestational-age) births and perinatal death. After adjustment for maternal background variables, the socioeconomic differences in preterm and low-birthweight births decreased in the late 1990s and remained low thereafter. In 2003-6, blue-collar workers had a 14% (95% CI 7% to 22%) higher risk for preterm birth and a 25% (95% CI 16% to 34%) higher risk for low birthweight than upper white-collar workers. For SGA, the socioeconomic differences remained unchanged, and the excess risk for blue-collar workers was 44% (95% CI 31% to 58%) in 2003-6. For LGA, the socioeconomic differences increased, and the highest excess risks were obtained among lower white-collar (23%, 95% CI 15% to 33%) and blue-collar workers (24%, 95% CI 14% to 36%). The differences in perinatal mortality decreased until the late 1990s, but increased thereafter. In 2003-6, lower white-collar and blue-collar workers had the highest excess risks: 46% (95% CI 20% to 77%) and 44% (95% CI 13% to 83%), respectively. Conclusions: The trends in social inequality in perinatal health outcomes were diverging by indicator. The positive trend on diminishing socioeconomic differences found in the 1990s seems to have come to an end.