Plasma amino acids in appropriate- and small-for-gestational-age fetuses.
The fetal plasma amino acid profiles of 28 small-for-gestational-age fetuses were established in umbilical venous blood samples obtained by cordocentesis and the values were compared with those of 62 appropriate-for-gestational age fetuses. In the appropriate-for-gestational-age group fetal levels were significantly correlated with but were higher than the maternal levels, which indicates that amino acids are actively transported by the placenta. In the small-for-gestational-age group, the fetal plasma concentration and the fetomaternal ratio of essential amino acids was decreased and this decrease was significantly correlated with the degree of fetal hypoxemia. There was a variable response (e.g., alanine was increased, whereas serine and tyrosine were decreased) involved with nonessential amino acids. In umbilical venous hypoxemia the plasma ratio of nonessential/essential amino acids was increased, and the maternal plasma concentrations of both essential and nonessential amino acids were increased. These findings suggest that in uteroplacental insufficiency there is intrauterine starvation.
Economides
D L
DL
Harris Birthright Research Centre for Fetal Medicine, King's College School of Medicine and Dentistry, London, United Kingdom.
Nicolaides
K H
KH
Gahl
W A
WA
Bernardini
I
I
Evans
M I
MI
D000596:Amino Acids / Q000097:blood*; D005260:Female; D005312:Fetal Blood; D005317:Fetal Growth Retardation / Q000097:blood*; D006801:Humans; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011247:Pregnancy; D012016:Reference Values; D012044:Regression Analysis
D000596:Amino Acids; D010100:Oxygen