S100B urine concentrations in late preterm infants are gestational age and gender dependent

Late preterm deliveries (LP, between 34 and 36wks), have considerably increased in the last decades. About 20–25% of LP infants who require intensive care and morbidity on public health are of great magnitude. Therefore, we aimed at offering a reference curve in LP period of a well-established neurotrophic and brain damage marker namely S100B protein. We collected, between December 2009 and March 2012, urine samples, at first void (within 6-hours from birth) for S100B assessment, in 277 healthy LP infants consecutively admitted to our units. Standard clinical and laboratory monitoring parameters were also recorded. S100B was measured by using a commercially available immunoluminometric assay. S100B pattern in LP infants was characterized by a slight decrease in protein's concentration from 34 to 35wks. From 35wks onwards S100B started to increase reaching a significant difference (P=0.008) at 36wks. When corrected for gender, significantly higher (P