Evaluation of the Association of Platelet Count, Mean Platelet Volume, and Platelet Transfusion With Intraventricular Hemorrhage and Death Among Preterm Infants

IMPORTANCE: Platelet transfusion is commonly performed in infants to correct severe thrombocytopenia or prevent bleeding. Exploring the associations of platelet transfusion, platelet count (PC), and mean platelet volume (MPV) with intraventricular hemorrhage (IVH) and in-hospital mortality in preterm infants can provide evidence for the establishment of future practices. OBJECTIVES: To evaluate the associations of platelet transfusion, PC, and MPV with IVH and in-hospital mortality and to explore whether platelet transfusion–associated IVH and mortality risks vary with PC and MPV levels at the time of transfusion. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study included preterm infants who were transferred to the neonatal intensive care unit on their day of birth and received ventilation during their hospital stay. The study was conducted at a neonatal intensive care unit referral center in Beijing, China, between May 2016 and October 2017. Data were retrieved and analyzed from December 2020 to January 2022. EXPOSURES: Platelet transfusion, PC, and MPV. MAIN OUTCOMES AND MEASURES: Any grade IVH, severe IVH (grade 3 or 4), and in-hospital mortality. RESULTS: Among the 1221 preterm infants (731 [59.9%] male; median [IQR] gestational age, 31.0 [29.0-33.0] weeks), 94 (7.7%) received 166 platelet transfusions. After adjustment for potential confounders, platelet transfusion was significantly associated with mortality (hazard ratio [HR], 1.48; 95% CI, 1.13-1.93; P = .004). A decreased PC was significantly associated with any grade IVH (HR per 50 × 10(3)/μL, 1.13; 95% CI, 1.05-1.22; P = .001), severe IVH (HR per 50 × 10(3)/μL, 1.16; 95% CI, 1.02-1.32; P = .02), and mortality (HR per 50 × 10(3)/μL, 1.74; 95% CI, 1.48-2.03; P < .001). A higher MPV was associated with a lower risk of mortality (HR, 0.83; 95% CI, 0.69-0.98; P = .03). The platelet transfusion–associated risks for both IVH and mortality increased when transfusion was performed in infants with a higher PC level (eg, PC of 25 × 10(3)/μL: HR, 1.20; 95% CI, 0.89-1.62; PC of 100 × 10(3)/μL: HR, 1.40; 95% CI, 1.08-1.82). The platelet transfusion–associated risks of IVH and mortality varied with MPV level at the time of transfusion. CONCLUSIONS AND RELEVANCE: In preterm infants, platelet transfusion, PC, and MPV were associated with mortality, and PC was also associated with any grade IVH and severe IVH. The findings suggest that a lower platelet transfusion threshold is preferred; however, the risk of a decreased PC should not be ignored.