Maternal mortality, marital status and bone mineral density in young women from the Coimbra identified skeletal collection

In contemporary populations, pregnancy and lactation are usually followed by transient bone loss. The observation of reduced bone mass in young females from archaeological sites has sometimes been interpreted as an outcome of reproductive stress. In order to evaluate the overall effect of reproductive dynamics on bone mass in a historical skeletal sample, bone mineral density (BMD) at the proximal femur was assessed by dual-energy X-ray absorptiometry in 78 young women (17–39 years) from the Coimbra Identified Skeletal Collection. BMD was compared within the skeletal sample (“maternal deaths” [ICD – 10: chapter XV] vs. “other causes of death”, and “married/widowed women” vs. “single women”). Results revealed that mean BMD differences among groups are non-significant, suggesting that a strict reproductive interpretation of premature bone loss in young women from archaeological contexts is not sustained by empirical evidence. Bone mass in young women from archaeological sites should be interpreted as a complex trait stemming from the interplay between reproductive factors, genetics, nutrition, physical activity, and age at menarche