Physiologic studies have indicated that hypoxia may act as a stress that reduces fecundity; and in human populations resident at high altitude there is evidence of reduced fertility. In this paper the fertility of high Andean populations is described with reference to the ecologic and social context. An analysis of high Andean energy flow indicates that children are an economic asset, and consideration of the social organization of high Andean rural communities supports this view. A study of the fertility of migrants from high to low altitude indicates that reproductive performance increases with the removal of the stress of hypoxia. It is therefore concluded that the reduced fertility observed in high Andean populations is due to the effect of hypoxia on human fecundity.
Abelson, A. E. (1976). Altitude and fertility. Human Biology, 48(1), 83–91. https://doi.org/10.1016/s0015-0282(16)30128-5