Optimal Transport and Placental Function

The human newborn is a reflection of the entirety of nutrients transferred from the maternal to the fetal circulation across the placenta during gestation. By extension, birth weight and newborn health depend on placental function. The goal of this chapter is to introduce the use of optimal transport modeling to study the expected effects of (i) placental size, (ii) placental shape (separate from size), and (iii) the position of insertion of the umbilical cord, on birth weight and placental functional efficiency. For each placenta (N = 1110), a total transport cost based on all measurements (i), (ii), and (iii) is given by the model. This computed cost is highly correlated with measured birth weight, placenta weight, the fetal–placental weight ratio (FPR), and the metabolic scaling factor beta. Next, a shape factor is calculated in a model of the total transport cost if each placenta were rescaled to have a unit area chorionic plate (thus separating shape from size). This shape factor is also highly correlated with birth weight, and after adjustment for placental weight, is highly correlated with the metabolic scaling factor beta.