Effect of red blood cell transfusion on the development of retinopathy of prematurity: A systematic review and meta-analysis

BACKGROUND: The effect of red blood cell (RBC) transfusion on retinopathy of prematurity (ROP) is difficult to establish, because ROP may also be influenced by other factors. Therefore, we carried out a systematic review and meta-analysis to explore the relationship between RBC transfusion and the development of ROP. METHODS: The PubMed, Embase, Cochrane Library and Web of Science databases were searched from their inception to September 1, 2019. Observational studies that reported the relationship between RBC transfusion and ROP after adjusting for other potential risk factors were included. The combined result was analyzed by a random effect model. Heterogeneity and publication bias were tested, and sensitivity analysis was performed. RESULTS: Of the 2628 identified records, 18 studies including 15072 preterm infants and 5620 cases of ROP were included. A random effect model was used and revealed that RBC transfusion was significantly associated with ROP (pooled OR = 1.50, 95% CI: 1.27–1.76), with moderate heterogeneity among the included studies (I(2) = 44.2%). Subgroup analysis indicated that RBC transfusion was more closely related to ROP in the group with a gestational age (GA) ≤32 weeks (OR = 1.77, 95% CI: 1.29–2.43) but not in the groups with a GA ≤34 weeks (OR = 1.36, 95% CI: 0.85–2.18) or a GA <37 weeks (OR = 1.25, 95% CI: 0.86–1.82). No obvious publication bias was found based on the funnel plot and Egger’s test. Removing any single study did not significantly alter the combined result in the sensitivity analysis. CONCLUSIONS: Our study revealed that RBC transfusion is an independent risk factor for the development of ROP, especially in younger preterm infants. However, there seemed to be no evidence to support an effect of RBC transfusion on ROP in older groups. Further studies addressing this issue in older preterm neonates are warranted.