Gestational Age-Specific Reference Ranges of Hepcidin in Cord Blood

Abstract

<b><i>Background:</i></b> Iron deficiency (ID) contributes to anaemia of prematurity, and hence the reliable assessment of iron nutrition status appears to be mandatory. <b><i>Objective:</i></b> To establish gestational age (GA)-specific reference ranges for hepcidin concentrations in cord blood [Hep<sub>(CB)</sub>] of preterm and term infants and to identify pre- and perinatal confounding factors. <b><i>Methods:</i></b> This is a prospective observational study including 221 infants (GA at birth: 24-42 weeks). Hep<sub>(CB)</sub> along with complete blood counts, ferritin and parameters of inflammation and clinical data were recorded. Data are presented as medians (IQR). <b><i>Results:</i></b> The Hep<sub>(CB)</sub> of very preterm infants (GA <30 weeks, n = 40) was 26.9 ng/ml (13.5-63.1), for moderately preterm infants (GA 30-36 weeks, n = 81) it was 45.9 ng/ml (24.7-74.5) and for term infants (GA ≥37 weeks, n = 100) it was 103.9 ng/ml (61.4-149.2). The Hep<sub>(CB)</sub> of infants with ID was lower [36.9 ng/ml (18.0-58.3)] than that of iron-replete infants [86.6 ng/ml (51.9-143.8)]. The Hep<sub>(CB)</sub> of infants delivered by elective caesarean section was lower [38.3 ng/ml (15.5-73.7)] than that of infants after spontaneous vaginal delivery or secondary caesarean section [80.3 ng/ml (48.5-137.6)]. Infants with a standard deviation score for birth weight (SDS<sub>BW</sub>) <-2 had a lower Hep<sub>(CB)</sub> [23.1 ng/ml (11.7-61.5)] compared to infants with SDS<sub>BW</sub> ≥-2 [71.1 ng/ml (34.0-121.7)]. The highest Hep<sub>(CB)</sub> (437.6 ng/ml) was recorded in an infant with <i>Enterococcus faecalis</i> sepsis. Multiple logistic regression analysis confirmed ferritin, GA and mode of delivery as important factors associated with Hep<sub>(CB)</sub>. <b><i>Conclusion:</i></b> This is the first report on GA-specific reference ranges for Hep<sub>(CB)</sub> in preterm infants. Whereas iron stores, GA and mode of delivery were associated with Hep<sub>(CB)</sub>, the association with inflammation and intra-uterine growth retardation was less clear.