Secular Trends of Children From Birth to 3 Years: Meta-Analysis of Data From Russia and the Neighboring Countries
The goal of the study is to investigate secular changes in main anthropometric characteristics of the newborns, infants and early age children, using the wide spectrum of the urban samples from modern Russia and the former USSR, through the course of several decades, from 1920th till now. The study summarizes the data of 338 samples of the newborns, 188 samples of the 12-months old infants, 168 samples of the 2-year old children, 256 samples of the 3-year old children. The secular dynamics of the body length describes the process of significant increase of the skeletal development of children of both sexes in all growth periods. This trend is combined with the stability in body mass parameter of the newborns and infants, significant increase in body mass of 2-year-olds, slight increase in body dimension in 3-year-old children aged. The values of head circumference in newborns decrease from the 1950’s to 2000’s by 1.1-1.2 cm, which could be explained by the trend of the decrease in maternal pelvic width discussed in the literature. This trend completely stops to the end of the first year of life, and the 12-months old infants experience secular stability of this parameter. The head and chest circumferences of 2- and 3-year-olds keep stable through the time period under consideration.