Background: Glucose-6- phosphate Dehydrogenase enzyme (G6PD) is an enzyme deficiency that is transported inheritably. The lack of this enzyme decreases the energy revival of red blood cells and leads to Hemolysis which is the cause of severe neonatal jaundice. This study aims to investigating glucose-6-phosphate dehydrogenase deficiency, hyperbilirubinemia, and blood incompatibility in newborn babies in larestan city, located in south of Fars province, following the newborn screening national plan.

Materials and Methods: This study is a cross-sectional and descriptive study on 12079 newborns in larestan city that referred to the screeing center from the start of 2010 to the end of 2012. The blood samples were taken from the newborns' heels and were evaluated through G6PD tluorescent spot test. They were examined regarding their blood group, hematocrit, hemoglobin, Coombs test, reticulocyte count and bilirubin levels as well as demographic information.

Results: In this research, among the 12079 screened newborns, 2345 ones showed G6PD deficiency with a prevalence of 19.41 which is a high percentage in comparison to those of other cities in Iran. The prevalence of O+ blood group among sick babies and their mothers was significantly higher than of other blood groups. (60% and 56%, respectively). The Hyperbilirubinemia and the indirect coombs tests were positive in 52% and 12% of the sick babies, respectively.

Conclusion: The prevalence percentage of lack of this enzyme in girls of Larestan city is a little higher than in boys, even though since this disease depends on X, it should be more prevalent in boys.