[The maternal, fetal and neonatal clinical characteristics in cases delivered between 24 and 32 weeks' gestation].

The clinical characteristics of 346 infants delivered between 24 and 32 weeks' gestation in our perinatal medical center were reviewed retrospectively in order to investigate the fetal development and maturation process in human pregnancy. Sixty nine infants were stillborn. The remaining 277 live-born infants were admitted in the neonatal intensive care unit. The one hundred and ninety three surviving infants were discharged from the neonatal unit. The neonatal survival rate by gestational week at birth was characterized by an abrupt increase at 26 weeks of gestation and a stepwise increment thereafter. Fetal cardiovascular responses to acute stress such as hypoxemia became different at 26 weeks of gestation from those of more preterm young infants. The capability to respond to various respiratory intensive support became evident at 28 weeks of gestation. The neurological development stability seems to be obtained at 30 weeks' of gestation. The neurological developmental disorders were not directly related to the length of gestational age at birth in the range of 26 and 32 weeks. The intrauterine growth retardation became clinically evident from 28 weeks. Those infants whose growth was retarded in utero showed a remarkably adverse outcome both in mortality and mobility in this series.