Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 18 1-4 1989 06 15 49 60 H.Eftekhar F. Azordegan 2015 10 03 In this research a comparative study has been made between case and control groups. The cases were low birth weight newborns (under 2500 Gr) and the controls were normal berth weighing 2500 Gr or more at birth. Four groups of birth weight were considered as follows: very low birth weight, Low birth weight, moderately low birth weight and normal. The data were collected over a period of 8 months, from 17 hospitals in Tehran in 1989. In this period 13123 births occurred. Some of findings are as follows: Out of these total 730 births was low birth weight (or 5.6%). In the first week 75% died in the same period. Early neonatal mortality and neonatal mortality rate in low birth weight newborn are approximately 24 times higher than normal birth in first week of their life. In this study neonatal mortality rate is calculated to be about 18 per thousand. https://ijph.tums.ac.ir/index.php/ijph/article/view/1632 https://ijph.tums.ac.ir/index.php/ijph/article/download/1632/1613