Maternal concentrations and fetal-maternal concentration differences of plasma amino acids in normal and intrauterine growth-restricted pregnancies


      OBJECTIVES: Our purpose was to determine whether maternal amino acid concentration changes during gestation in pregnancies with intrauterine growth restriction as in normal pregnancies and to verify whether these changes are related to changes in fetal-maternal differences. STUDY DESIGN: Amino acid concentrations were measured in 5 nonpregnant women, in 11 second-trimester and 10 third-trimester pregnant women with appropriate-for-gestational-age fetuses, and in 23 pregnant women with intrauterine growth restriction. Umbilical venous amino acids were measured at the time of fetal blood sampling. The severity of intrauterine growth restriction was assessed by Doppler velocimetry and fetal heart rate and by evaluation of oxygenation and acid-base balance. RESULTS: In normal pregnant women the maternal concentration of most amino acids was significantly lower in both the second and third trimesters compared with nonpregnant women. In intrauterine growth restriction the maternal concentrations of most essential amino acids were significantly higher than in appropriate-for-gestational-age pregnancies. This observation, coupled with lower fetal amino acid concentrations in intrauterine growth restriction, leads to significantly lower fetal-maternal differences. CONCLUSIONS: Normal pregnant women have a significant decrease in amino acid concentrations compared with nonpregnant women, whereas in intrauterine growth restriction maternal amino acids are reduced less. Significantly lower fetal-maternal concentration differences are present in intrauterine growth restriction, independent of the degree of severity. (AM J OBSTET GYNECOL 1996;174:1575-83.)


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        • Bonsnes RW.
        The plasma amino acid and amino nitrogen concentration during normal pregnancy, labor and early puerperium.
        J Biol Chem. 1947; 168: 345-352
        • Schoengold DM
        • DeFiore RH
        • Parlett RC.
        Free amino acids in plasma throughout pregnancy.
        AM J OBSTET GYNECOL. 1978; 131: 490-499
        • Young M
        • Prenton MA.
        Maternal and fetal plasma amino acid concentrations during gestation and in retarded fetal growth.
        J Obstet Gynaecol Br Commonw. 1969; 76: 333-344
        • Kalkhoff RK
        • Kandaraki E
        • Morrow PG
        • Mitchell TH
        • Kelber S
        • Borkowf HI.
        Relationship between neonatal birth weight and maternal plasma amino acid profiles in lean and obese nondiabetic women and in type 1 diabetic pregnant women.
        Metabolism. 1988; 37: 234-239
        • Cockburn F
        • Blagden A
        • Michie EA
        • Forfar JO.
        The influence of pre-eclampsia and diabetes mellitus on plasma free amino acids in maternal, umbilical vein and infant blood.
        J Obstet Gynaecol Br Commonw. 1971; 78: 215-231
        • Moghissi KS
        • Churchill JA
        • Kurrie D.
        Relationship of maternal amino acids and proteins to fetal growth and mental development.
        AM J OBSTET GYNECOL. 1975; 123: 398-407
        • McClain PE
        • Metcoff J
        • Crosby WM
        • Costiloe JP.
        Relationship of maternal amino acid profiles at 25 weeks of gestation to fetal growth.
        Am J Clin Nutr. 1978; 31: 401-407
        • Cetin I
        • Corbetta C
        • Sereni LP
        • Marconi AM
        • Bozzetti P
        • Pardi G
        • et al.
        Umbilical amino acid concentrations in normal and growth-retarded fetuses sampled in utero by cordocentesis.
        AM J OBSTET GYNECOL. 1990; 162: 253-261
        • Economides DL
        • Nicolaides KH
        • Gahl WA
        • Bernardini I
        • Evans MI.
        Plasma amino acids in appropriate and small-for-gestational-age fetuses.
        AM J OBSTET GYNECOL. 1989; 161: 1219-1227
        • Prenton MA
        • Young M.
        Umbilical vein-artery uterine arterio-venous plasma amino acid differences (in the human subject).
        J Obstet Gynaecol Br Commonw. 1969; 76: 404-411
        • Cetin I
        • Marconi AM
        • Bozzetti P
        • Sereni LP
        • Corbetta C
        • Pardi G
        • et al.
        Umbilical amino acid concentrations in appropriate- and small-for-gestational-age infants: a biochemical difference present in utero.
        AM J OBSTET GYNECOL. 1988; 158: 120-126
        • Daffos F
        • Capella-Pavlowsky M
        • Forestier F.
        Fetal blood sampling during pregnancy with use of a needle guided by ultrasound: a study of 606 consecutive cases.
        AM J OBSTET GYNECOL. 1985; 153: 655-660
        • Pardi G
        • Cetin I
        • Marconi AM
        • Lanfranchi A
        • Bozzetti P
        • Ferrazzi E
        • et al.
        Diagnostic value of blood sampling in fetuses with growth retardation.
        N Engl J Med. 1993; 328: 692-696
        • Sonnenberg GE
        • Keller V.
        Sampling of arterialized heated-hand venous blood as a non-invasive technique for the study of ketone body kinetics in man.
        Metabolism. 1982; 31: 1-5
        • Todros T
        • Ferrazzi E
        • Groli C
        • Nicolini U
        • Parodi L
        • Pavoni M
        • et al.
        Fitting growth curves to head and abdomen measurements of the fetus: a multicentric study.
        J Clin Ultrasound. 1987; 15: 95-105
        • Parazzini F
        • Cortinovis I
        • Bortolus R
        • Fedele L.
        Standard di peso alla nascita in Italia.
        Ann Ost Ginecol Med Perin. 1991; 112: 203-246
        • Marconi AM
        • Cetin I
        • Buscaglia M
        • Pardi G.
        Midgestation cord sampling: what have we learned.
        Placenta. 1992; 13: 115-122
        • Gosling RG
        • King DH.
        Continuous wave ultrasound as an alternative and complement to x-rays in vascular examinations.
        in: Cardiovascular applications of ultrasound. North Holland, Amsterdam1974: 266-282
        • Wolf H
        • Boer K.
        Ultrasonographic placental volume measurement to predict fetal outcome.
        in: A critical appraisal of fetal surveillance. Elsevier Science, Amsterdam1994: 430-436