On correlation between age of parents and length and weight of the newborn infant.

Abstract

It seems reasonable to assume that a number of factors influence the size of the human individual at various stages of development. Pearson and his co-workers have shown the great importance of hereditary factors. They have found that in general such environmental factors as they have been able to consider play a much smaller rôle in determining the characteristics of the individual. Nevertheless it seems important to investigate all such factors in as great detail as possible, with a view to disentangling those factors which are innate in the zygote from which the individual develops from those which are extrinsic to the individual, and to measuring quantitatively the relative importance of each. It seems especially desirable to consider certain morphogenetic factors. The purpose of this paper, which is one of a series dealing with the physical characteristics of the newborn infant of various races, is to consider the possible relationships between the age of the parents and the length and weight of the newborn child. The data represent measurements on infants of the white race taken at the Sloane Hospital for Women, New York City, and recorded in the archives of the Obstetric Divisions of that institution. For opportunity of using these records we are indebted to the late Dr. W. E. Studdiford, who was Superintendent at the time this phase of the investigation was undertaken. Since it is possible that the average age of parents and the average dimensions of the newborn infant differ from nationality to nationality, we have considered separately the charactceristics of infants born of Austrian, English, German, Irish, Italian and Russian parents. Both parents were born in the countries designated. By the examination of about 43,000 records assembled over a period of about 30 years (September, 1890, to September, 1921), it was possible to secure the following numbers of measurements of length and weight.