PLATELET INDICES AS PREDICTORS OF LATE-ONSET SEPSIS AND MORTALITY IN THROMBOCYTOPENIC NEONATES: A RETROSPECTIVE COHORT STUDY

Deniz YAPRAK, Mina MISIRLIGİL, Belma Saygılı KARAGÖL, Ebru DUMLUPINAR

Türkiye Çocuk Hastalıkları Dergisi - 2026;20(5):355-362

Department of Neonatology, Gülhane Training and Research Hospital, University of Health Sciences, Ankara, Türkiye

 

Objective: Late-onset neonatal sepsis (LOS) is frequently complicated with thrombocytopenia. The aim of this study was determine the prevalence of LOS, and whether platelet indices affect LOS and mortality in neonates with thrombocytopenia in the neonatal intensive care unit (NICU) population. Materials and Methods: This retrospective observational cohort study included neonates admitted to a level 4 NICU between 2018 and 2022 who developed thrombocytopenia (platelet count <150x10?/L). Platelet indices were recorded during thrombocytopenic episodes preceding or coinciding with late-onset sepsis (LOS). Multivariable logistic regression and Cox proportional hazards models were used. Results: A total of 223 (13.3%) thrombocytopenic neonates were included in the study. According to multivariable logistic regression analysis, multiparity (OR: 3.32 95% CI 1.40-7.89, p=0.006), caesarean section (OR: 5.81, 95% CI 1.99-16.89, p<0.001), invasive ventilation (OR: 8.43 95% CI 3.60-19.75, p<0.001, high MPV levels (OR: 1.62 95% CI 1.24-2.12, p<0.001) and duration of thrombocytopenia (OR: 1.13 95% CI 1.06-1.20, p=0.001), duration of hospitalization (OR: 1.03 95% CI 1.01-1.05, p=0.004) were independently associated with the development of LOS. Multivariable Cox hazard modelling demonstrated that invasive ventilation (HR: 9.459, 95% CI 3.38-26.45, p<0.001), platelet transfusion (HR: 2.833 95% CI 1.54-5.20, p=0.001), lymphopenia (HR: 0.766, 95% CI 0.64-0.92, p=0.003), grade 2>= of NEC (HR: 7.274, 95% CI 1.68-31.52, p=0.008), any type of haemorrhage (HR: 2.728, 95% CI 1.69-9.10, p=0.001), platelet nadir (HR: 0.972, 95% CI 0.96-0.98, p<0.001), MPV (HR: 0.805, 95% CI 0.66-0.98, p=0.032), and lymphopenia (HR: 0.745, 95% CI 0.63-0.89, p=0.001) independently predicted overall mortality. Conclusion: Key findings indicate that larger platelet sizes, prolonged thrombocytopenia, and extended hospitalization are linked to late neonatal sepsis. Furthermore, lower platelet levels characterized by smaller platelet sizes and the necessity for platelet transfusions may also contribute to these adverse outcomes.