Neonatal screening of ABO/RhD blood group and direct antiglobulin Coombs test. Experience of a single institution.

Background: Evaluating the ABO/RhD blood group and the direct antiglobulin Coombs test (DAT) at birth is recommended good practice, but there is variability in its universal implementation. This study aims to show the comparative results in various variables of clinical impact during the hospital stay of neonates with positive DAT compared with those with negative DAT, based on the systematic detection of the ABO/RhD group and DAT at birth.

Methods: Newborns between 2017 and 2020 in a high-risk pregnancy care hospital were included. The ABO/RhD and DAT group was determined in umbilical cord samples or the first 24 hours of life. Demographic, maternal, and neonatal variables were recorded. The association between the variables was estimated using the odds ratio (OR).

Results: 8721 pairs were included. The DAT was positive in 239 newborns (2.7%), with the variables associated with positive PDC being maternal age > 40 years (OR: 1.5; 95% CI: 1.0 to 2.3), birth by cesarean section (1.4; 1.1-2.0), mother group O (6.4; 3.8-11.8), prematurity (3.6; 2.6-5.0), birth weight < 2500 g (2.1; 1.6-2.8), newborn group A (15.7; 10.7-23.1) and group B (17.6; 11.4-27.2), hemoglobin at birth < 13.5 g/dl (4.5; 2.8-7.1) and reticulocytosis > 9% (1.9; 1.2 to 3.1).

Discussion: The frequency of neonatal positive PDC was 2.7%, with a significant association with maternal/neonatal incompatibility to the ABO and RhD group, with a substantial impact on various neonatal variables. These results support the policy of universal implementation at the birth of the ABO/RhD and DAT determination.