Reconstruction of two mother-infant dyads and obstetrical consequences of the Mesolithic-Neolithic transition: A case study from Lepenski vir and Vlasac (Serbia)

Abstract

The current world population of approximately seven billion people shows that despite the complexities of human birthing, the human species is thriving. Changes in human pelvic morphology resulting from bipedalism and encephalisation, often described as the “obstetric dilemma”, have made the birthing process extremely difficult and risky for both mothers and neonates. The major Mesolithic-Neolithic shift in lifestyle could have had important obstetric consequences. It is often hypothesised that the shift to an agricultural diet, with a lower protein content and higher glycaemic loading than the hunter-gatherer diet, could have led to a decrease in maternal height and an increase in neonatal birth weight, brain size and foetal-pelvic strain, which may have exacerbated the obstetric dilemma. The Mesolithic-Neolithic osteological collection from the Danube Gorges (7400-5500 cal BC, Balkans) provides material (2 pelvises and a neonate skull) to test this hypothesis by virtually reconstructing the fossil dyads and their foetal-pelvic relationship. We compared these dyads with a large obstetrical sample of mother-child dyads with a known birthing history, conducting a linear-discriminant analysis in order to predict the most probable delivery outcomes for the prehistoric dyads. The results suggest that delivery was dystocic for the Mesolithic mother-child dyad and eutocic for the Neolithic mother-child dyad; obstetrically, the former is notably more efficient. However, due to the small sample size, further research is required with a larger series in order to determine whether the development of obstetrically efficient pelvic bones in the Neolithic was widespread and whether it had an impact on the birthing process and thus potentially contributed to the increasing size of the population.