BackgroundAnemia of prematurity (AOP) is a common issue in neonatal intensive care units (NICUs) globally, associated with significant morbidity and mortality. Near-infrared spectroscopy (NIRS) has emerged as a noninvasive, real-time monitoring tool to assess tissue oxygenation and blood flow, potentially providing valuable insights into the impact of red blood cell transfusions in preterm infants with anemia. This study aimed to evaluate the effectiveness of NIRS in assessing improvements in preterm infants after red blood cell transfusions.MethodsThis study followed a systematic review and meta-analysis design, adhering to the Cochrane Handbook for Systematic Reviews of Interventions and PRISMA guidelines. No geographic or temporal restrictions were imposed during the search. The final included studies spanned 2008-2017 and originated from four countries. A total of 214 articles were initially identified, and nine prospective observational studies were included in the final analysis. These studies focused on preterm infants diagnosed with anemia who required red blood cell transfusion therapy. The sample sizes in these studies ranged from 10 to 35 infants. The primary outcome was the changes in NIRS readings before and after transfusion. The secondary outcomes included changes in heart rate (HR), saturation of pulse oxygen (SPO2), and hemoglobin (Hb) pre- and post-transfusion.ResultsMeta-analysis demonstrated significant post-transfusion increases in CrSO2 (mean difference [MD] = -8.51, 95% CI: -12.34 to -4.68) and SrSO2 (MD = -15.68, 95% CI: -20.12 to -11.24). Subgroup analyses revealed greater improvements in CrSO2 for infants with higher baseline anemia severity (MD = -14.76, 95% CI: -18.19 to -11.33) and in SrSO2 (MD = -22.79, 95% CI: -26.96 to -18.62). Cerebral fractional tissue oxygen extraction (cFTOE) and splanchnic fractional tissue oxygen extraction (sFTOE) also showed significant changes. Hemoglobin levels increased post-transfusion (MD = -2.89, 95% CI: -3.21 to -2.57), while heart rate and peripheral oxygen saturation (SPO2) remained unchanged.ConclusionsThe findings suggest that NIRS is a reliable tool for assessing the impact of red blood cell transfusions in preterm infants.Trial RegistrationPROSPERO (ID: CRD42024596069).