Interpregnancy intervals and perinatal and child health in Sweden: a comparison within families and across social groups
Population Studies (2019), forthcoming
A large body of research has shown that children born after especially short or long birth intervals have an elevated risk of poor perinatal outcomes, but recent work suggests this may be explained by confounding by unobserved family characteristics. We use Swedish population data on cohorts born 1981-2010 and sibling fixed effects to examine whether the length of the birth interval preceding the index person influences the risk of preterm birth, low birth weight, and hospitalization during childhood. We also present analyses stratified by salient social characteristics such as maternal educational level and maternal country of birth. We find few effects of birth intervals on our outcomes except for very short intervals (<7 months), and very long intervals (>60 months). We find few differences in the patterns by maternal educational level, or by maternal country of origin after stratifying by the mother’s highest attained education.
Keywords: Sweden, birth weight, hospitalization, interpregnancy interval, population registers, siblings