Blood parameters of preterm neonates: postnatal evolution according to gestational age

The blood count provides qualitative and quantitative essential information on bloodlines. Reference hematologic parameters have been established in children and neonates, but few data are available regarding the premature population during the first month of life. The main objective of this study was to establish normative values for blood parameters for premature infants born between 26 and <37 weeks of gestation, during the first month of life, taking into account gestational and postnatal age and treatments that can impact the threshold values.

A single-center retrospective study was conducted based on the clinical and laboratory data of preterm infants born between January 1, 2012 and December 31, 2013 and hospitalized in the intensive care, neonatal, and maternity units of University Hospital of Saint Etienne (France). Data were collected by crossing the PMSI database (date of birth and gestational age), the administrative patient database (IPP), and the pre-analytical laboratory database. Anthropometric and clinical data were extracted for both mother and child. The samples were all made from central or peripheral venous blood. All blood parameters were taken into account.

The degree of prematurity is a factor greatly influencing the values of the blood parameters at birth. All three blood lines increase in proportion to gestational age. We were able to highlight for some blood parameters specific kinetic profiles according to gestational age.

Blood parameters of preterm neonates depend on both the degree of prematurity, postnatal age, and perinatal treatments. A good knowledge of these physiological variations may help target transfusion or therapeutic indications in everyday practice.