ABSTRACT
Jaundice in neonatal period is a common disorders that increase bilirubin deposision in tissues such as skin occurs.excessive bilirubin deposision in the brain increase the risk encephalopathy and kernicterus. there are several therapeutic procedures to reduce bilirubin level. One of the most important method especially in emergency situation is exchang transfusion [ET]. This study was performed to find the causes of sever hyper bilirubinemia which required ET. This study was an analytical descriptive retrospective and prospective study which was performed in 48 cases in milad hospital [Tehran -Iran] from 1381 - 1386. the data were collected by pediatrician in a detailed questionnaire. This data were fully analyzed by SPSS 16 software. In this study 48 neonates age 1-32 days were enrolled. 24 patients [50%] were male and 50% were female 34 patient [77%] were term and 14 patient [23%] were preterm. retic count in most patient were low [less than 2%]. There was no specific cause for jaundice in 12 [24%] cases. ABO incompatibility was the most common cause of jaundice. ABO incompatibility was the most common cause ET which can be prevented by in paying attention to postnatal visit. there was no specific cause of jaundice 12 [24%] cases which required further investigation. In this study no positive coomb,s test was seen .coomb,s test under this situation little value