Document Detail

Maternal and fetal blood ammonia concentrations in normal term human pregnancies.
MedLine Citation:
PMID:  15523170     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: The current evidence on the primary source of ammonia production in the human fetoplacental unit is potentially misleading.
OBJECTIVE: The aim of the present investigation was to determine the concentration of ammonia in human maternal and fetal blood at birth and to compare them with published data in late gestation sheep.
METHODS: In 12 normal human pregnancies, umbilical arterial and venous and maternal venous blood was sampled, and whole blood ammonia concentrations were measured. Data from 12 pregnant sheep and fetuses from our previous studies were utilized for comparison.
RESULTS: The human fetus at delivery has higher concentrations of ammonia (60-80 microM) than the late gestation fetal lamb (25-35 microM). In the human, the arterial umbilical ammonia concentration exceeds the venous umbilical concentration, indicating a net ammonia production by fetal tissues. In sheep, the venous umbilical ammonia concentration exceeds the arterial umbilical concentration, indicating the net placental ammonia production.
CONCLUSIONS: In contrast to fetal lambs, human fetuses exhibit a net production of ammonia, which may reflect differences in biologic state or a species difference.
Maciej Jóźwik; Marcin Jóźwik; Bartosz Pietrzycki; Marcin Chojnowski; Cecilia Teng; Michał Jóźwik; Frederick C Battaglia
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.     Date:  2004-10-26
Journal Detail:
Title:  Biology of the neonate     Volume:  87     ISSN:  0006-3126     ISO Abbreviation:  Biol. Neonate     Publication Date:  2005  
Date Detail:
Created Date:  2005-01-03     Completed Date:  2005-04-18     Revised Date:  2011-12-06    
Medline Journal Info:
Nlm Unique ID:  0247551     Medline TA:  Biol Neonate     Country:  Switzerland    
Other Details:
Languages:  eng     Pagination:  38-43     Citation Subset:  IM    
Department of Gynecology, Medical University of Białystok, Białystok, Poland.
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MeSH Terms
Ammonia / blood*
Fetal Blood / chemistry*
Gestational Age
Infant, Newborn
Reference Values
Sheep / blood
Species Specificity
Umbilical Arteries
Umbilical Veins
Grant Support
Reg. No./Substance:

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