Measurement of total body fat in low birth weight infants

Growth is one of the most important phenomena of childhood, particularly in infancy. Growth velocity in the human is greater during the first year than in subsequent years. A healthy, full term, West-European baby trebles his birth weight in the first year, while in the same period his body length increases by approximately a half. This rapid increase in weight and length is however surpassed by the intra-uterine growth velocity. From the beginning of the pregnancy, the growth velocity, expressed in grams per day gradually increases. Growth velocity is greatest in the eighth month of pregnancy, being approximately 35 grams per day. The weight increase is however proportionally greatest in the first trimester of pregnancy, being approximately 6% per day and gradually decreasing to about 1.5% per day by 38 weeks of gestation. Growth of the body as a whole, as well as that of the various individual organs, takes place through an increase in the number of cells and through an increase in their size. It was shown in animals by Winick and Noble (1966), that growth follows a definable pattern. This is probably the same in all mammals, including man, although the time scale varies between species. Three consecutive stages of growth can be defined according to Winick and Nobel (1966).