Hypoxia: Animal experiments and clinical implications

The developing fetus has some unique physiological properties that differ from properties in extra-uterine life. The fetus exists in a hypoxemic condition as a result of the presence of the placenta, which serves as a limiting interface between maternal and fetal circulation. In addition, the fetus is prone to be exposed to uterine contractions, which place it under a further hypoxic burden. Thus, the fetal response to hypoxic insults is important. There has been marked progression in the understanding of fetal physiology since the introduction of the 'chronic preparation model'. Based upon information from animal research, we now utilize medical technologies in daily medical care, for example, fetal heart rate monitoring and high-resolution ultrasonographic devices. In this review, we discuss the main findings in relation to fetal physiology and their clinical relevance.