MPIDR Working Paper
Secular changes in the association between advanced maternal age and the risk of low birth weight: a cross-cohort comparison in the UK
MPIDR Working Paper WP-2015-010, 45 pages.
Rostock, Max Planck Institute for Demographic Research (November 2015)
Existing studies provide contradictory evidence concerning the association between child well-being and advanced maternal ages. A potential explanation for the lack of consensus are changes over time in the costs and benefits of giving birth at advanced ages. This is the first study that tests secular changes in the association between advanced maternal age and child health. We use data from four UK cohort studies covering births from 1958-2001, and use low birth weight as a marker for child health. We find that across successive birth cohorts, the association between advanced maternal age and low birth weight becomes progressively weaker, and is negligible statistically and substantively for the 2001 cohort. Among current cohorts advanced maternal age does not predict low birth weight, but if selection into older maternal ages had not changed, it would still predict strongly increased risk of giving birth to a low birth weight child.