Trends in infant mortality rate and mortality for neonates born at less than 32 weeks and with very low birth weight.

The aim of the study was to assess the trend of the infant mortality rate between 1990-2004 and the neonatal mortality between 2000-2005 in infants born at less than 32 weeks of gestational age or with very low birth-weight. Based on secondary data, infant mortality rate and by its component for Valdivia city were compared with national indicators. Mortality at <32 weeks and <1500g was calculated, establishing causes of death and evaluating its relation with specific interventions, such as the use of surfactant and antenatal corticoids. Since the year 2000, infant mortality rates have stopped their decrease in comparison to the preceding decade and the gap between national and local rates before 2000 was drastically reduced. Mortality at <32 weeks and <1500g varied between 88% and 200% of liveborns, emphasizing respiratory distress as the main cause of death. The use of corticoids and surfactant was in line with reductions in mortality rates.