Did the grandmother’s exposure to environmental stress during pregnancy affect the birth body size of her grandchildren? The Polish evidence

This study aimed to examine whether the exposure of grandmothers (G1s) pregnant with their daughters (G2s) to the harsh conditions of the First World War and the Great Depression influenced the perinatal outcomes of their grandchildren (G3s). We use the data on full-term live births in 1951–1953.

The following cohorts are selected: grandmothers (G1s), mothers (G2s), and grandchildren (G3s: males and females). Birth body size (weight, length, and birth body mass index) of G3s born to G2s were compared considering G1s’ period of pregnancy: pre-WWI, WWI, post-WWI, and the Great Depression. We use ART ANOVA to assess statistical differences in birth weight, length, and BMI without and with controlling for co-factors, such as: G2s’ age at delivery, and G3’s gestational age, and birth order.

The grandmother’s pregnancy during the harsh conditions of WW I and the Great Depression resulted in the blurring of dimorphic differences in the generation of grandchildren in terms of their birth body size, i.e. weight, length, and BMI. The results demonstrate the potential impact of harsh conditions experienced by grandmothers on the perinatal outcomes of their grandchildren. We do not specify the mechanisms of stress transmission to subsequent generations but assume these are likely to stem from epigenetic mechanisms and/or the G2 mothers’ biological status.