Abstract: Objective To explore the effect of exchange transfusions (ETs) on the internal environment of newborns, and to provide guidelines for safe procedure. Methods Fourty neonates were included with haemolytic disease of the foetus and newborn（HDFN）from January 2016 to December 2018. The change of blood routine examination, biochemistry and coagulation indicators were evaluated before and after ETs. Results After ETs, total bilirubin, direct bilirubin and indirect bilirubin decreased from 390.4±17.98 μmol/L, 18.41±1.038 μmol/L and 370.4±18.16 μmol/L to 271.6±12.93 μmol/L, 8.08±0.97 μmol/L and 255.5±13.4 μmol/L respectively（P<0.001）; There was no significant difference in prothrombin time（PT）and activated partial thromboplastin time（APTT）（P>0.05）; Red blood cells count, hemoglobin and blood glucose increased from（3.1±0.13）×10¹²/L, 114.8±4.66 g/L, 3.92±0.19 mmol/L to（4.58±0.11）×10¹²/L, 137.3±3.18 g/L and 8.35±0.59 mmol/L respectively（P<0.001）. Conclusion ETs can significantly decline the serum bilirubin level and improve clinical symptoms, but it showed some influence on some biochemical, blood routine and coagulation indexes. During and after the procedure, we should pay attention to these indexes for the safety of ETs.

Key words: Newborn, Hyperbilirubinemia, Exchange transfusions, Blood routine examination, Coagulation function