Introduction. Premature birth is a major problem of contemporary obstetrics, but also of public health, whose incidence is increasing in the developed countries. Pregnancy duration, fetal body weight, physical and neurological condition are directly correlated with mortality rate and comorbidities of premature babies. Aim of the study. Evaluation of the incidence, risk and medico-social impact of premature births in dependence on body mass and gestational age. Materials and methods. As study material of premature births served statistics of years 20162019, the risk factors and causes of morbidity and mortality in newborns. Were questioned 52 children over one year old, born prematurely. Results. Several risk factors were detected, the most important being prematurity. The medicosocial impact of preterm births is highlighted in the perinatal period by the high mortality of the newborns. With advancing age, the negative impact is diminished. After the age of one year, the risks of preterm babies do not have a statistically significant difference with those born at term. Conclusions. Premature births have multifactorial etiology. The medico-social impact of premature births is enhanced by morbidity and mortality in the perinatal period.