In vivo techniques for studying fetoplacental nutrient uptake, metabolism, and transport

This chapter presents experimental methods to measure in vivo uteroplacental nutrient substrate uptake, transfer to the fetus, and metabolism by the uteroplacental unit. The fundamental method involves application of the Fick principle, which requires determination of uterine and umbilical blood flow rates and measurement of nutrient substrate arterial and venous concentrations in the uterine and umbilical circulations. Surgical approaches to placing catheters into these circulations are described. Details are provided to illustrate key concepts for net rates of uteroplacental glucose and amino acid uptake, transfer to the fetus, and net uteroplacental uptake.