Abstract
The Hypothalamic – Pituitary – Adrenal (HPA) Axis is a unique system that mediates an immediate reactivity to a wide range of stimuli. It has a crucial role in synchronizing the behavioral and hormonal responses to internal and external threats, therefore, increases the chance of survival. It also enables the body systems to adapt to challenges put up by the pregnancy. Since the early stages of pregnancy and throughout delivery, HPA axis of the mother continuously navigates that of the fetus, and both have a specific cross talk even beyond the point of delivery and during postnatal period. Any disturbance in the interaction between the maternal and fetal HPA axes can adversely affect both. The HPA axis is argued to be the mechanism through which maternal stress and other suboptimal conditions during prenatal period can program the fetus for chronic disease in later life. In this chapter, the physiological and non-physiological communications between maternal and fetal HPA axes will be addressed while highlighting specific and unique aspects of this pathway.