Mechanisms of Fetal Adaptation to Chronic Hypoxia following Placental Insufficiency: A Review

Placental insufficiency is associated with reduced oxygen and nutrient supply to the fetus, which may result in fetal growth restriction (FGR). In an attempt to cope with the hostile intrauterine environment, FGR fetuses respond through metabolic, endocrine, vascular, cardiac, behavioral, hematological, and immunological adaptive mechanisms. However, permanent sequelae may result from such adaptive mechanisms. In this review, we describe the mechanisms of fetal adaptation to the hostile intrauterine environment in FGR of uteroplacental origin and detail their pathophysiology and potential implications for the extrauterine life of the individual.