TY  - JOUR
AB  - Background: Despite iron supplementation, some preterm infants develop iron deficiency (ID). The optimal iron status parameter for early detection of ID has yet to be determined. Objective: To establish reference ranges for reticulocyte haemoglobin content (Ret-He) in preterm and term infants and to identify confounding factors. Methods: Retrospective analyses of Ret-He and complete blood count in infants with a clinically indicated blood sample obtained within 24 h after birth. Results: Mean (SD) Ret-He was 30.7 (3.0) pg in very preterm infants with a gestational age (GA) of < 30 weeks (n = 55), 31.2 (2.6) pg in moderately preterm infants (GA 3036 weeks, n = 241) and 32.0 (3.2) pg in term infants (GA = 37 weeks, n = 216). The 2.5th percentile of Ret-He across all GA groups was 25 pg, with a weak correlation between Ret-He and GA (r = 0.18). Moreover, only weak/no correlations were found between Ret-He and C-reactive protein (r = 0.18), interleukin 6 (IL-6) (r = 0.03) and umbilical artery pH (r = -0.07).There was a slight variation in Ret-He with mode of delivery [normal vaginal delivery: 32.3 (3.2) pg, secondary caesarean section (CS): 31.4 (3.0) pg, instrumental delivery: 31.3 (2.7) pg and elective CS: 31.2 (2.8) pg]. Conclusion: GA at birth has a negligible impact on Ret-He, and the lower limit of the normal reference range in newborns within 24 h after birth can be set to 25 pg. Moreover, Ret-He seems to be a robust parameter which is not influenced by perinatal factors within the first 24 h after birth.
AU  - Lorenz, L.*
AU  - Peter, A.
AU  - Arand, J.*
AU  - Springer, F.*
AU  - Poets, C.F.*
AU  - Franz, A.R.*
C1  - 50817
C2  - 42893
CY  - Basel
SP  - 189-194
TI  - Reference ranges of reticulocyte haemoglobin content in preterm and term infants: A retrospective analysis.
JO  - Neonatology
VL  - 111
IS  - 3
PB  - Karger
PY  - 2017
SN  - 1661-7800
ER  - 

TY  - JOUR
AB  - Reticulocyte haemoglobin content, i.e., the reticulocyte equivalent (Ret-He), seems to be a promising parameter for the detection of iron deficiency (ID) in neonates because it can be obtained as part of a reticulocyte count, with no additional blood loss and at no extra cost. Due to the short life span of reticulocytes, Ret-He reflects current iron availability for erythropoiesis more accurately than other common erythrocyte indices. OBJECTIVE: We aimed to evaluate postnatal changes in Ret-He within the first days after birth in term and preterm infants with the hypothesis that preterm infants experience a more pronounced postnatal reduction in Ret-He when compared to term infants. METHODS: We conducted retrospective analyses of clinically indicated blood samples. Paired t test and mixed regression modelling were used. RESULTS: In total, 805 blood samples obtained from 207 term and 295 preterm infants were analysed. Ret-He decreased by 1.5 pg per day (regression coefficient [95% CI] -1.5 [-1.8 to -1.2] pg, p < 0.0001). This drop was more significant in preterm infants (regression coefficient -2.2 [-2.6 to -1.8] pg, p < 0.0001) than in term infants (regression coefficient -0.8 [-1.3 to -0.2] pg, p < 0.01, pinteraction < 0.0001). CONCLUSION: Ret-He declined within the first days after birth. The observed changes with postnatal age were more pronounced in preterm than in term infants. Further studies are needed to evaluate if these changes are due to developing ID or other causes.
AU  - Lorenz, L.*
AU  - Peter, A.
AU  - Arand, J.*
AU  - Springer, F.*
AU  - Poets, C.F.*
AU  - Franz, A.R.*
C1  - 52818
C2  - 44181
SP  - 246-250
TI  - Reticulocyte haemoglobin content declines more markedly in preterm than in term infants in the first days after birth.
JO  - Neonatology
VL  - 112
IS  - 3
PY  - 2017
SN  - 1661-7800
ER  -