Fertility resilience varies by socioeconomic status and sex: Historical trends in childlessness across 150 years.
Level 3 - non-randomized controlled study
Non-randomized historical longitudinal cohort study
PubMed 39021810 · doi:10.1016/j.isci.2024.110227
What was done
Analyzed a historical genealogical dataset tracking reproduction across family lineages for 150 years (spanning birth cohorts from 1800 to 1945–1949) in Finland. The authors examined trends in lifetime childlessness stratified by socioeconomic status (SES) and sex during the demographic transition and societal/economic crises.
What was found
Lifetime childlessness doubled from the 1800 birth cohort to the 1945–1949 cohort. Higher SES indicated a higher lifetime likelihood to reproduce. Fluctuations in childlessness over time were driven by the low SES group, whereas high and moderate SES showed a steady increase. Exact sample sizes, baseline rates, and effect sizes were not provided in the abstract.
Why it matters
Highlights that reproductive resilience during historical demographic and economic crises was socially patterned, with lower socioeconomic groups bearing the largest and least-recuperated disruptions in family formation.
Limits
The abstract does not provide exact sample sizes, baseline percentages, or numerical effect estimates. The study is restricted to historical Finnish lineage data, limiting direct generalizability to other geographic contexts and modern populations. Abstract data do not distinguish voluntary from involuntary childlessness.