Plasma amino acid concentrations throughout normal pregnancy and early stages of intrauterine growth restricted pregnancy.
OBJECTIVE
Assessment of maternal plasma amino acids during normal gestation and in early stages of intrauterine growth restriction (IUGR).


METHODS
Plasma amino acid concentrations were measured in: (1) non-pregnant women (n=7); (2) normal pregnant women in the first (n=13), second (n=17) and third (n=12) trimester; and (3) pregnant women in the first trimester with later development of IUGR (n=8). Amino acid levels were quantified by electrochemical detection in a reversed-phase high-performance liquid chromatography (HPLC) system.


RESULTS
The levels of most essential and non-essential amino acids changed markedly in the first trimester during normal pregnancy and thereafter remained almost constant. In the first trimester of IUGR, a number of both essential and non-essential amino acids were significantly different from those observed in normal pregnancies, with values more similar to those observed in non-pregnant women.


CONCLUSIONS
Levels of most maternal amino acids decrease and some increase during early gestation reflecting a metabolic adaptation that occurs in normal pregnancies. Pregnancies that later develop IUGR show a lack of these adaptations for a significant number of both essential and non-essential amino acids, suggesting a lack of adaptation.
Di Giulio
A M
AM
Department of Medicine, Surgery and Dentistry, School of Medicine, University of Milan, Polo San Paulo, via A. di Rudini 8, 20142 Milan, Italy.
Carelli
S
S
Castoldi
R E
RE
Gorio
A
A
Taricco
E
E
Cetin
I
I
D000222:Adaptation, Physiological; D000596:Amino Acids / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005317:Fetal Growth Retardation / Q000097:blood*; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012016:Reference Values
D000596:Amino Acids