PMID- 24030675
OWN - NLM
STAT- MEDLINE
DCOM- 20140924
LR  - 20211021
IS  - 1476-5543 (Electronic)
IS  - 0743-8346 (Linking)
VI  - 34
IP  - 2
DP  - 2014 Feb
TI  - Estimating the nucleated red blood cell 'emergence time' in neonates.
PG  - 116-9
LID - 10.1038/jp.2013.113 [doi]
AB  - OBJECTIVE: The time between onset of fetal hypoxia and first appearance of 
      nucleated red blood cells (NRBCs) in the blood can conceptually be divided into 
      two periods; (1) the 'erythropoietin (EPO) generation time', which previous fetal 
      studies suggest is 4 to 5 h, and (2) the 'NRBC emergence time'. In this study, we 
      estimated the latter as the time required for NRBC to appear in the blood after 
      administering a dose of recombinant EPO. STUDY DESIGN: This was a retrospective 
      analysis of data from a multihospital healthcare system (Intermountain 
      Healthcare). Data were included only for neonates born >/=34 weeks gestation 
      between the dates 1 January 2005 and 31 October 2012 and only if they received a 
      dose of darbepoetin during their neonatal intensive care unit stay and had one or 
      more complete blood cell counts (CBCs) obtained during the 3-day period before 
      the dose was given and one or more CBCs in the 7-day period after the dose. 
      RESULT: The study involved 31 neonates who received 34 doses of darbepoetin. 
      Seven doses were 4 mug kg(-1) and twenty-seven doses were 10 mug kg(-1). Twenty-six 
      CBCs were obtained during the 24-h period following the darbepoetin dose and none 
      had NRBC identified. NRBC first appeared in the blood between 24 and 36 h after 
      the dose. Recipients of the higher dose generally had a higher peak NRBC count 
      but the NRBC 'emergence time' did not appear to depend on dose. CONCLUSION: 
      Following fetal hypoxia, transcription and translation of the EPO gene result in 
      an elevation in plasma EPO concentration. Previous fetal studies suggest this 
      process requires 4 to 5 h. The present studies suggest that, following the 
      increase in plasma EPO, NRBC emerge into the circulation in >/=24 h. If this model 
      serves as a reasonable estimate, it suggests that neonates with an elevated NRBC 
      count at birth had the onset of hypoxia at least 28 to 29 h before birth.
FAU - Christensen, R D
AU  - Christensen RD
AD  - Department of Women and Newborns, Intermountain Healthcare, Salt Lake City, UT, 
      USA.
FAU - Lambert, D K
AU  - Lambert DK
AD  - Department of Women and Newborns, Intermountain Healthcare, Salt Lake City, UT, 
      USA.
FAU - Richards, D S
AU  - Richards DS
AD  - 1] Department of Women and Newborns, Intermountain Healthcare, Salt Lake City, 
      UT, USA [2] Department of Obstetrics and Gynecology, University of Utah School of 
      Medicine, Salt Lake City, UT, USA.
LA  - eng
PT  - Journal Article
DEP - 20130912
PL  - United States
TA  - J Perinatol
JT  - Journal of perinatology : official journal of the California Perinatal 
      Association
JID - 8501884
RN  - 11096-26-7 (Erythropoietin)
RN  - 15UQ94PT4P (Darbepoetin alfa)
SB  - IM
CIN - J Perinatol. 2014 Feb;34(2):85-6. PMID: 24476660
MH  - Blood Cell Count
MH  - Darbepoetin alfa
MH  - Erythrocytes/drug effects/*physiology
MH  - Erythropoietin/*analogs & derivatives/blood/pharmacology/therapeutic use
MH  - Fetal Hypoxia/*blood
MH  - Gestational Age
MH  - Humans
MH  - Infant, Newborn
MH  - Retrospective Studies
MH  - Time Factors
EDAT- 2013/09/14 06:00
MHDA- 2014/09/25 06:00
CRDT- 2013/09/14 06:00
PHST- 2013/05/14 00:00 [received]
PHST- 2013/07/08 00:00 [revised]
PHST- 2013/08/05 00:00 [accepted]
PHST- 2013/09/14 06:00 [entrez]
PHST- 2013/09/14 06:00 [pubmed]
PHST- 2014/09/25 06:00 [medline]
AID - jp2013113 [pii]
AID - 10.1038/jp.2013.113 [doi]
PST - ppublish
SO  - J Perinatol. 2014 Feb;34(2):116-9. doi: 10.1038/jp.2013.113. Epub 2013 Sep 12.