Increased neonatal urinary ammonia: a marker for in utero caloric deprivation?
The decline in the urinary urea to ammonia ratio represents a simple measure of nutritional status in the adult. We examined the relationship of this ratio to nutrient-related fetal growth retardation. Levels of ammonia and urea nitrogen were measured in the first voided urine and cord blood from 15 term infants exhibiting a wide range of growth. Analysis by multiple regression with neonatal ponderal index as the primary dependent variable revealed a significant correlation between lowered ponderal index and decreased urinary urea and ammonia. The correlation was primarily a function of increasing ammonia levels, with no relationship between fetal leanness and urinary urea. Comparable cord artery and vein ammonia suggest that placental ammoniagenesis was not a major determinant of observed elevations in urinary ammonia. Confirmation of the striking correlation between increased urinary ammonia and lowered neonatal ponderal index may afford a simple test for the identification of nutrient-related growth retardation.
Wolfe
H M
HM
Hutzel Hospital, Wayne State University, Department of Obstetrics and Gynecology, Detroit, MI 48201.
Sokol
R J
RJ
Dombrowski
M P
MP
Bottoms
S F
SF
Norman
G S
GS
D000328:Adult; D000641:Ammonia / Q000652:urine*; D005260:Female; D005317:Fetal Growth Retardation / Q000175:diagnosis*; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age / Q000652:urine*; D009752:Nutritional Status; D010922:Placenta Diseases / Q000175:diagnosis*; D010927:Placental Insufficiency / Q000175:diagnosis*; D011247:Pregnancy; D012044:Regression Analysis; D012307:Risk Factors; D014508:Urea / Q000652:urine
D000641:Ammonia; D014508:Urea