Demographics WUSTL.xlsx from Gestational growth trajectories derived from a dynamic fetal–placental scaling law

Fetal trajectories characterizing growth rates <i>in utero</i> have relied primarily on goodness of fit rather than mechanistic properties exhibited <i>in utero</i>. Here, we use a validated fetal–placental allometric scaling law and a first principles differential equations model of placental volume growth to generate biologically meaningful fetal–placental growth curves. The growth curves form the foundation for understanding healthy versus at-risk fetal growth and for identifying the timing of key events <i>in utero</i>.