Age-wise reference range of immature platelet fraction in neonates.

Immature platelet fraction (IPF) is a quantification of immature platelets in the circulation reflecting the state of thrombopoiesis in the marrow. Normal reference range for IPF has been established in adults. Reference intervals in neonates are highly dependent on gestational age of the neonate. Complete blood counts (CBC) with IPF of all neonates admitted in neonatal intensive care unit (NICU) were analyzed using Mindray BC-6800 Auto Hematology analyzer. Platelet count of less than 150 × 10^9/L was assigned as thrombocytopenia. Neonates were divided into four groups as per the corrected gestational age (CGA) on the day of CBC analysis: 28-32 weeks, 32-34 weeks, 34-37 weeks, and >37 weeks according to World Health Organization (WHO) classification. Mean, standard deviation, and 95% confidence interval for IPF was calculated in each group and reference range for IPF was derived. Mean IPF in neonates with normal platelet count was term--3.58 (95% CI 3.29 to 3.87), late preterm Neonates (34-37 weeks)--4.14 (95% CI 3.82 to 5.0), moderate preterm neonates (32-34 weeks)--4.14 (95% CI 3.46 to 4.82), and in Very Preterm neonates (28-32 weeks)--IPF of 5.51 (95% CI 3.95 to 7.07). We aimed to establish a reference range for IPF in neonates of different gestational age groups. The IPF values in neonates were comparable between hematology analyzers in neonates with normal platelet counts.