Ravi M. Patel, M.D., M.Sc., of the Emory University School of Medicine & Children's Healthcare of Atlanta, and colleagues examined whether red blood cell transfusion and severe anemia were associated with the rate of necrotizing enterocolitis (an acute, life-threatening, inflammatory disease occurring in the intestines of premature infants) among very low-birth-weight (VLBW) infants. The study appears in JAMA.

Necrotizing enterocolitis (NEC) is a leading cause of mortality among preterm infants with case-fatality rates of 20 percent to 30 percent. The origin and development of NEC remains unclear with conflicting data regarding the role of 2 risk factors, red blood cell (RBC) transfusion and anemia. Improving understanding of the role of RBC transfusion and anemia is important because more than half of VLBW (3.3 lbs. or less) infants receive 1 or more transfusions during hospitalization. This study included VLBW infants enrolled at 3 neonatal intensive care units in Atlanta within 5 days of birth. Infants received follow-up until 90 days, hospital discharge, transfer to a non-study-affiliated hospital, or death (whichever came first).

Of 600 VLBW infants enrolled, 598 were evaluated. Forty-four (7.4 percent) infants developed NEC. Thirty-two (5.4 percent) infants died (all cause). Fifty-three percent of infants (319) received a total of 1,430 RBC transfusion exposures. Analyses indicated that RBC transfusion was not significantly related to the development of NEC, although the rate of NEC was significantly increased among VLBW infants with severe anemia compared with those who did not have severe anemia.

"Because severe anemia, but not RBC transfusion, was a risk factor for NEC in this study, preventing severe anemia may be more clinically important than minimizing RBC transfusion exposure as a strategy to decrease the risk of NEC. However, the effect of such a strategy on other important neonatal outcomes is unclear, and further study is needed. Ongoing clinical trials comparing liberal vs conservative transfusion practices may provide additional experimental data regarding the risks of both severe anemia and RBC transfusion to NEC," the authors write.