Newborn's weight and correlated with it size parameters are subject to continuous fluctuations. According to Penrose, it depends on the external factors in 62%. Socioeconomic mother's condition of living is the most important factor. The study aimed at assessing the somatic state of newborn infants born in the Regional Hospital in Police.Research material consisted of the measurements of newborn infants born in Police hospital's maternity ward in 2005. The measurements of 738 newborns have been carried out - 374 girls and 364 boys, who were born after normal and unifetal pregnancy. The mass and length of body as well as the circumferance of head and chest have been measured. The data have been statystically analyzed.The research confirmed the observed sexual dimorphism in the average weight of a newborn infant at birth. Male newborn infants are significantly heavier than the female ones. Newborn infants born in the third quarter attained the largest birth parameters. The largest number of deliveries occurred in winter months.The study suggests that regional monitoring of newborn infant genotypic variation should be carried out in order to develop regional standards allowing for climatic variation.