The importance of immunohematology testing in the neonatal period

Abstract

INTRODUCTION: In order to diagnose hemolytic disease of the newborn it is necessary to determine ABO/Rh blood group, direct antiglobulin test and indirect antiglobulin test in newborns as well as ABO/Rh and indirect antiglobulin test in their mothers due to a possible incompatibility between the blood types of the mother and her baby. The study was aimed at reviewing and analyzing the results of screening of the newborns and pregnant women on the territory of South Backa District during 2011, as well as at estimating the necessity to give blood transfusion to the newborns in the same period. MATERIAL AND METHODS: Data obtained from the information system and protocol of the Institute for Blood Transfusion of Vojvodina were used in a retrospective analysis of screening of newborns and pregnant women. RESULTS: Blood samples taken from 3313 newborns were tested and the following distribution of the ABO blood types was recorded: O in 45.6%, A in 35%, B in 15.9%, AB in 3.5%; 78.9%, newborns were found to be D-positive, 21.1% were D-negative. The direct antiglobulin test was positive in 165 (4.9%) cases, it was weakly positive +/- in 85 (51.5%), positive 1+ in 45 (27.3%), positive 2+ in 17 (10.3%), positive 3+ in 12 (7.3%), positive 4+ in 6 (3.6%). In all cases, the monospecific direct antiglobulin test was positive with IgG antibodies. Of four newborns with positive direct antiglobulin test who required exchange blood transfusion, two had RhD incompatibility and two had ABO incompatibility. Blood samples of 3429 (100%) women were tested and 36 (1.05%) were actively immunized: 23 (0.67%) to RhD antigen, 8 (0.23%) to blood group antigens other than ABH and Rh, specificity could not be determined in 5 (0.15%). Anti-D antibodies were found in 19 (0.55%) pregnant women, in two (0.06%) cases newborns required exchange blood transfusion. CONCLUSION: Testing neonates and pregnant women contributes to the detection of blood type incompatibility between the mother and her child; it provides an opportunity for clinicians to implement the adequate prevention of RhD alloimmunization as well as to make timely diagnosis and to introduce treatment of hemolytic disease in newborns.