Results of the Inter-American Investigations of Mortality relating to reproduction.

Maternal age and parity, according to the findings of the Inter-American Investigation of Mortality in Childhood, have a direct relationship to the health and survival of the infant. Among the results of this broad undertaking are data suggesting that babies born close in succession, especially within large families and as birth order ascends, are at greater risk of dying. Also, the offspring's future is increasingly threatened as the mother's age tends toward the extremes of the childbearing years. Compromise of the mother's health, in turn, was indicated in the earlier Investigation, a study of deaths in adults, which revealed unexpectedly high maternal mortality in the Latin American cities that it covered. Immaturity, or low birthweight, and malnutrition emerged as the two major underlying or associated causes of death in the Latin American projects of the Inter-American Investigation of Mortality in Childhood. Despite the marked variations in the data available from the different areas, there appeared to be some correlation between these two indicators of deficits in growth and development. Mortality due to immaturity was especially high for babies of young mothers, with increases occurring as the birth order rose. Not only are the risks greater for mothers having low-weight babies when they are young (under 20), but they increase even more with the second, third, and fourth products when the birth intervals become shorter. Maternal age, birth order, and birthweight are factors that must be considered in combination in the programming of protective health measures.