Survival predictors of preterm neonates: Hospital based study in Iran (2010-2011)

BACKGROUND Preterm birth (PTB) is responsible for 70% of neonatal mortalities. Various factors influence the risk of neonatal mortality in different populations. OBJECTIVE Our objective was to evaluate neonatal survival rate of preterm infants, and to define its predictors in Iranian population. MATERIALS AND METHODS This retrospective cohort study included all preterm (26-37 weeks) infants (n=1612) born alive in Shahid Akbar-abadi university hospital, during one year period (April 2010-2011). These infants were evaluated for fetal-neonatal, maternal, and pregnancy data. Survival analysis was performed and viability threshold and risk factors of neonatal mortality were evaluated. RESULTS Total overall mortality rate was 9.1%. Survival rate were 11.11% for extremely low birth weights (LBW) and 45.12% for very early PTBs. The smallest surviving infant was a 750 gr female with gestational age (GA) of 30 weeks and the youngest infants was a 970 gram female with GA of 25weeks plus 2 days. History of previous dead neonate, need to cardio-pulmonary resuscitation (CPR), need to neonatal intensive care unit (NICU) admission, postnatal administration of surfactant, presence of anomalies, Apgar score <7, multiple pregnancy, non-cephalic presentation, early PTB, very early PTB, LBW, very low birth weight (VLBW) and extremely low birth weight (ELBW), were risk factors for mortality in preterm neonates. CONCLUSION Our study revealed that neonatal survival rate is dramatically influenced by birth weight especially under 1000grams, GA especially below 30 weeks, neonatal anomalies, history of previous dead fetus, multiple pregnancy, non- cephalic presentation, and need for NICU admission, resuscitation and respiratory support with surfactant.