Grandparental income and adverse neonatal outcomes in Finland in 2000 − 2015

Abstract

Abstract Background Pre-term births and other adverse neonatal outcomes are a major burden to healthcare systems, and they also contribute to long-term health problems. Socioeconomic inequalities in these outcomes are well-documented, but whether grandparental characteristics influence them over and above parental characteristics remains unclear. Methods We used population register data on all singleton children of non-migrant origin, born in Finland in 2000 − 2015 (n = 341,715), linked to their both biological parents and all four grandparents, including an indicator for deceased kin members. We examined whether grandparental income predicted grandchildren's neonatal outcomes (preterm birth, low birth weight, small for gestational age, congenital malformations) in addition to parental income, once accounting for sociodemographic family characteristics such as parental age, parity, education, family structure, and maternal smoking. Results We found a consistent association between lower income and adverse neonatal outcomes, for both mothers and fathers, as well as maternal and paternal grandparents. The gradient was stronger among young mothers (under age 25), e.g., the prevalence of being born small for gestational age was 11% for the highest parental or grandparental income quintile, while for the lowest it ranged from 13 to 15%. Overall, the income gradients clearly attenuated in adjusted models, but remained. Preliminary results suggest grandparental characteristics mainly influence grandchild outcomes through the middle generation, but depending on the outcome, partly independent associations remain. Conclusions Even in the context of a Nordic welfare state, offspring of lower income grandparents are at higher risk of adverse neonatal outcomes, particularly when born to young mothers. This influence mainly, but not fully, passes through the parental generation, suggesting more support should be offered to expecting parents with low income and from disadvantaged backgrounds. Key messages • Lower grandparental income predicts higher risk of adverse neonatal outcomes, particularly when born to young mothers. • Expecting parents with low income and disadvantaged family background should be supported to reduce adverse neonatal outcomes.