In a population sample, whose congruity with the country-wide population was verified, the birthweight, menstrual age and gestational age (assessed by repeated ultrasonic foetometry in the course of pregnancy) were mutually correlated. A group of 80% of newborns out of the total population sample, in whom no disturbance of foetal growth rate was found throughout the course pregnancy, served as the basis for preparation of the standard of normal foetal growth. In the interval from the 36th to the 42nd week of pregnancy a highly significant linear relationship between gestational age and birthweight was found, without terminal flattening of the "normal foetal growth curve". In the remaining 20% of the population there was a twofold predominance of growth retardation over growth acceleration.