Intergenerational Transmission of Birth Weight Across Three Generations

While previous studies have shown intergenerational transmission of birth weight from mother to child, only one study has assessed whether this continuity persists across three generations. We used the Aberdeen Maternity and Neonatal Databank to examine the intergenerational correlations of birth weight, birth weight adjusted for gestational age and sex, and small- and large for gestational age births among 1457 grandmother-mother-grandchild triads across three generations. All participants were born between 1950 and 2015. The intergenerational transmission was examined with linear regression analyses. Our findings showed that grandmaternal birth weight was associated with grandchild birth weight, independently of prenatal and sociodemographic covariates and maternal birth weight (B=0.12 Standard deviation units, 95% Confidence Interval=0.07, 0.18). Similar intergenerational continuity was found for birth weight adjusted for sex and gestational age, and for small for gestational age births. To conclude, birth weight and fetal growth show intergenerational continuity across three generations. The developmental origins of birth weight and hence later health and disease are already present in earlier generations.