Early-life social and health determinants of adult socioeconomic position: Associations and trends across generations

Background: Social and biological circumstances at birth are established predictors of adult socioeconomic position (SEP). This study aims to assess the trends in these associations across two generations and examine the effects of parental early-life characteristics on descendants' adult SEP. Methods: We studied men and women born in the Uppsala University Hospital 1915-1929 (G1) and their offspring born 1932-1960 (G2). Data were collected in archives and routine registers. Adult SEP was assessed as an aggregate measure combining education and occupation. The exposures were family SEP, mother's marital status, mother's parity, mother's age, standardised birth weight, gestational length and birth multiplicity. Linear regression was used to examine the associations across generations. Results: The difference in adult SEP between low and high family SEP at birth was 15.8 (95% CI: 13.3 to 18.3) percentage points smaller in G2 compared with G1, although a considerable difference was still evident in G2. The associations of adult SEP with small birth weight for gestational age, post-term birth and high parity were stable between the generations: the generational differences in adjusted coefficients were 1.5 (95% CI: -1.1 to 4.1), 0.6 (-1.7 to 2.9) and 1.8 (-0.2 to 3.8) percentage points, respectively. The association between grandparental and grandchildren's SEPs was largely explained by parental socioeconomic conditions. Father's preterm birth was independently associated with offspring's SEP. Conclusion: The stability of the associations between early-life biological disadvantages and adult SEP and the persistent, although attenuated, association between early-life and adult SEPs necessitates increased policy attention to both social and health conditions at birth.