Developmental changes in amino acid concentrations in human amniotic fluid: Abnormal findings in maternal phenylketonuria

George H. Thomas, Tim H. Parmley, Roger E. Stevenson, R. Rodney Howell

Research output: Contribution to journalArticle

20 Scopus citations


The amino acid composition of amniotic fluid samples obtained from 51 patients at various stages of fetal gestation was determined by column chromatography. There is a decreasing concentration of most of the amino acids with increasing gestational age. The maximum rate of this decrease occurs between the twenty-second and the twenty-fourth week of pregnancy. As it is well established that the offspring of women with phenylketonuria (PKU) will have in most cases intrauterine and postnatal growth retardation, mental retardation, and/or structural abnormalities, amniotic fluid samples from 2 pregnancies of a woman affected with PKU were also analyzed. In both pregnancies (eighth and fortieth weeks of gestation) the amniotic fluid phenylalanine concentration was elevated to about 35 times that of normal.

Original languageEnglish (US)
Pages (from-to)38-42
Number of pages5
JournalAmerican journal of obstetrics and gynecology
Issue number1
StatePublished - Sep 1 1971
Externally publishedYes


ASJC Scopus subject areas

  • Obstetrics and Gynecology

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