Question

Mammalian fetuses develop in conditions dubbed ‘Everest in utero’. Explain what ‘Everest in utero’ refers to and why it is important for normal development.

Answer 1

'Everest in utero' :

Intertwining his interests in the hypoxia of high altitude and in fetal physiology, Barcroft equated the fetus to the acclimatised highland mountaineer. He coined the phrase 'Everest in utero', a term now used extensively to teach the conditions in which the fetus normally develops.

The human fetus develops in a profoundly hypoxic environment. Thus, the foundations of our physiology are built in the most hypoxic conditions that we are ever likely to experience: the womb. This magnitude of exposure to hypoxia in utero is rarely experienced in adult life, with few exceptions, including severe pathophysiology in critical illness and environmental hypobaric hypoxia at high altitude. Indeed, the lowest recorded levels of arterial oxygen in adult humans are similar to those of a fetus and were recorded just below the highest attainable elevation on the Earth's surface: the summit of Mount Everest. We propose that the hypoxic intrauterine environment exerts a profound effect on human tolerance to hypoxia. Cellular mechanisms that facilitate fetal well-being may be amenable to manipulation in adults to promote survival advantage in severe hypoxemic stress. Many of these mechanisms act to modify the process of oxygen consumption rather than oxygen delivery in order to maintain adequate tissue oxygenation. The successful activation of such processes may provide a new chapter in the clinical management of hypoxemia. Thus, strategies employed to endure the relative hypoxia in utero may provide insights for the management of severe hypoxemia in adult life and ventures to high altitude may yield clues to the means by which to investigate those strategies.