RESUMO
The objective of this study is to determine risk factors causing increase in very low birth way [VLBW] neonatal mortality. The medical files of all neonates weighing <1500 gram, born in Vali-e-Asr hospital [2001-2004] were studied. Two groups of neonates [living and dead] were compared up to the time of hospital discharge or death. A total of 317 neonates were enrolled. A meaningful relationship existed between occurrence of death and low gestational age [P=0.02], low birth weight, lower than 1000 gram [P=0.001], Apgar score <6 at 5[th] minutes [P=0.001], resuscitation at birth [P=0.001], respiratory distress syndrome [P=0.001] need for mechanical ventilation [P=0.001], neurological complications [P=0.001] and intraventricular hemorrhage [P=0.001]. Regression analysis indicated that each 250 gram weight increase up to 1250 gram had protective effect, and reduced mortality rate. The causes of death of those neonates weighting over 1250 gram should be sought in factors other than weight. Survival rate was calculated to be 80.4% for neonates weighing more than 1000 gram. The most important high risk factors affecting mortality of neonates are: low birth weight, need for resuscitation at birth, need for ventilator use and intraventricular hemorrhage