Fetal oxygen and glucose utilization of uncomplicated monochorionic twins: Adapting to the intrauterine environment

•Estimation of fetal oxygen and glucose metabolism is feasible in human pregnancy.•Monochorionic twins reduce their metabolic needs to endure in a poor environment.•Second-born twins show lower birthweight, oxygenation and metabolic rates.•Monochorionic placenta may have uneven metabolic functions.