average life expectancy at birth has increased by years over the period years in and years in since the lowest life expectancy values are observed in domod aimag years in years in and years in and khuvsgul aimag years in years in and years in in the major causes of death in under yearolds were related to certain conditions originating in the perinatal period congenital malformations deformations and chromosomal abnormalities and diseases of the respiratory system