Impact of ABO blood group on NEC incidence and mortality in VLBW infants.

Background: This study aimed to investigate the relationship between ABO blood group and the incidence of necrotizing enterocolitis (NEC) or mortality in very low birth weight (VLBW) infants.

Methods: A retrospective single-center cohort study was conducted on VLBW infants admitted to Shengjing Hospital of China Medical University from 2014 to 2023. Bell's staging system was used to define NEC severity, and deaths were recorded. Confirmed NEC with Bell's stage ≥2 and mortality were defined as primary outcomes and compared among the four ABO blood groups.

Results: The primary composite outcome occurred in 14.7% (847/5774). Among the 5774 VLBW infants enrolled, the overall mortality was 11.0% (635/5774). Confirmed NEC (Bell's stage ≥2) occurred in 5.0% (288/5774) of the cohort, with NEC-related mortality of 21.2% (61/288). ABO blood groups were not associated with mortality and the incidence of NEC in VLBW infants. These findings remained consistent after adjusting for perinatal factors, maternal factors, and admission year.

Conclusions: This study suggests no significant association between ABO blood group and NEC incidence, severity, or mortality in VLBW infants, contrasting with previous reports. Variations in study populations, definition of primary outcomes, statistical methods, and transfusion strategies may explain the differing findings. Conclusions: ABO blood groups have no influence on the incidence of confirmed NEC or mortality in VLBW infants. Variations in study populations, definitions of primary outcomes, and statistical methods may explain discrepancies between our findings and previous reports. Transfusion strategies may also confound the relationship between ABO blood group and NEC.