Maternal Blood Group and Routine Direct Antiglobulin Testing in Neonates: Is There a Role for Selective Neonatal...

Area of Science:

• Neonatal Medicine
• Immunology
• Blood Group Serology

Background:

• Current recommendations for screening hemolytic disease of the newborn (HDN) suggest a selective approach for direct antiglobulin test (DAT) in mothers with blood group O or RhD-negative.
• The effectiveness of this selective screening strategy requires further evaluation in relation to neonatal outcomes.

Purpose of the Study:

• To assess the relationship between direct antiglobulin test (DAT) results and maternal/neonatal blood groups.
• To evaluate the risk of hemolytic disease of the newborn (HDN) and the need for phototherapy based on blood group compatibility and DAT status.

Main Methods:

• Retrospective analysis of 1463 healthy newborns admitted in 2018.
• Categorization of maternal-neonatal pairs based on ABO and RhD blood groups.
• Analysis of direct antiglobulin test (DAT) positivity and requirement for phototherapy.

Main Results:

• 4.4% of newborns had a positive DAT. ABO incompatibility was observed in 37% of pairs, predominantly with mothers of blood group O.
• Neonates born to mothers with blood group O showed a higher DAT positivity rate (8.3%), particularly in the O-B group (49.2%) compared to the O-O control group (13.6%, p < 0.01).
• While O-B neonates were more likely to need phototherapy (p=0.03), this was not linked to DAT results. Selective testing strategies were ineffective in predicting phototherapy needs.

Conclusions:

• Selective direct antiglobulin test (DAT) screening for mothers with blood group O or RhD-negative is not effective in identifying neonates requiring phototherapy.
• There is no significant difference in the need for phototherapy among neonates born to mothers of different blood types, irrespective of DAT results.