Considering that the last intrauterine growth standards were constructed more than two decades ago, the authors defined the measure of 5, 10, 25, 50, 75, 90 and 95 percentiles of birth weight on the base of Genetic and Obstetric Computer Register of East-Hungary, birth data having epidemiological value in Szabolcs-Szatmár-Bereg, Hajdú-Bihar and Jász-Nagykun-Szolnok counties in 1988-89. From the 36th week of pregnancy the mean values of birth weights between boys and girls, boys and gipsy boys, girls and gipsy girls as well as singular and twin newborn infants differed from each other significantly. Possessing these standards, the clinical judgement and supplying of the various newborn infants can be more exact.