Pregnant women and premature born children were classified into four groups. In each group there were thirty of them. The first group included the pregnant women with premature rupture of membranes and amniotic fluid effluxed for 72 hours before the delivery. The second group included the pregnant women with amniotic fluid effluxing less then 72 hours before the delivery. The third group included the pregnant women who were given corticosteroids. The forth group was a control group formed by those pregnant women (and their premature born children) whose amniotic fluid did not efflux long and those who weren't given corticosteroids during pregnancy. In all groups of pregnant women we observed: median age of pregnant women, the duration of pregnancy and mode of delivery (vaginal or cesarean section). In groups of premature born children we also observed: newborn birth weight, Apgar score in the first minute after delivery, Apgar score in the fifth minute after delivery, pH of the blood of umbilical cord, L/S ratio of amniotic fluid (lecithin-sphingomyelin ratio), RDS (neonatologist valuation in any degree of RDS developed et newborn child). Symptoms of RDS include tachypnoea, chest wall retraction and cyanosis and a zground glass' appearance of the chest on X-ray. Histopatological examinations of placentas compared the frequency of inflammatory or noninflammatory changes, also in all groups. No significant difference was found among groups of pregnant women for the following factors: the age of pregnant women, the duration of pregnancy and mode of delivery. No significant difference was found among the groups of children for the following factors: newborn birth weight, Apgar score in the fifth minute after delivery, blood pH of umbilical cord, L/S ratio of amniotic fluid. Significant difference was found among groups for the following factors: Apgar score in the first minute after delivery, the frequency of RDS and hystology of placentas. The prevention of premature delivery is the most important. All the pregnant women with symptoms of the premature delivery must be transported to the centers with the well developed unites of intensive neonatal care ("transport in utero").