[Survival at discharge of newborn infants weighing less than 1000 g (1991-1997). When are they too small?].

OBJECTIVE: To describe survival rates at discharge in liveborn infants with birth-weight under 1000 g by birth-weight and gestational age categories in a third level spanish hospital in order to improve health care planning and parental counselling about the threshold of viability. STUDY DESIGN: A follow-up study of 178 infants with birth-weight under 1000 g born alive between 1991 at 1997. Six newborns with lethal malformations were not included. RESULTS: Overall survival at discharge was 54%. During the study period survival rate improved in the birth-weight group 750-999 g. In the group below 750 g survival rate was lower and improved more slowly. Survival rate for infants below 750 g and 26 weeks was extremely low. Over 749 g and 25 weeks survival was over 50%. CONCLUSIONS: Survival rate showed an improving trend during the study period. In the last years of the study period survival in infants with birth-weight over 749 g was above 85%. For infants under 750 g and 26 weeks was extremely low. Family and medical decision making about active treatment of these newborns should be an individualized process.