Selection, Distribution and Change in Birth Weights during Crisis and Growth Periods in a Finnish near-Complete Count Urban Data, 1921-1945

Sakari Saaritsa, University of Helsinki
Jarmo Peltola, University of Helsinki

Recent work on birth weights has on one hand reaffirmed their association with later life outcomes, on the other hand produced findings challenging the notion that birth weights are an appropriate indicator for standard of living or fetal health variation in general. Literature on selection into fertility and selection in utero during crisis periods has demonstrated the critical role of such filters for neonatal health outcomes, which may show improvement in unconditional distributions during stressful periods. We leverage a rare dataset on the near-complete universe of births in the Finnish city of Tampere in 1921-1945 (c. 35 000 births) to precisely measure the variation in the distribution of birth weights and underlying factors, including selection, during the various crisis and growth periods in these years. In addition to standard birth record indicators like weight, parity and gestation, the data contains e.g., birth order, mother’s age, mother’s or spouse’s occupation, mother’s age at menarche, and identifying information. As the economic and social history of the city has been carefully reconstructed, we are able to estimate the impact of well-defined economic shocks and stress factors on several aspects of maternal and child health. It is possible to analyze selection into fertility via compositional changes in the background of the mothers and selection in utero via changes in gestational age, prematurity and sex ratios at birth (SRB). During the crisis of the 1930s, for instance, there was a marked drop in fertility, a change in the SES composition of mothers, and a collapse in the SRB, as often observed following stress. We aim for a detailed understanding of the different selection mechanisms affecting observed births and infant health metrics in such circumstances, from fertility decisions via primary sex ratio to prematurity/miscarriages and SRB.

No extended abstract or paper available

 Presented in Session 165. Determinants of Mortality: Disease, Disability, and Climate Impacts