[Use of screening for amino acid disorders in the study of the nutrition of the newborn infant: various milk formulas and changes in plasma amino acids].

A sample of 1326 new-born babies has been studied regarding the influence of the milk diet over some plasma-serum amino acids. The Authors have make use of the screening of the congenital errors of the protein metabolism. New-born babies were bled on the fifth or sixth day of life and their blood was analysed at first with the Guthrie test and then with automatic chromatographic determination. New-born babies have been arranged according to their gestational age, birth weight and intrauterine growth. More then 90% of the sample was formed by normal for gestational age new-born babies. We have make use of five different milk formulas: a mixed one (human milk with adapted milks), three powdered milks with three different casein-serum proteins ratio and finally cow's milk with 50% water. The best formula among these ones has been the human milk mixed with adapted milks. The completely artificial formulas, but with casein/serum proteins ratio lower or equal to one, has given rise to a few amino acid alterations, too. On the contrary, the cow's milk mixed with water and the artificial powdered milks with a casein-serum proteins ratio equal to 4.5 shouldn't be utilized in the new-born baby's diet, as they may provoke remarkable alteration in the amino acid metabolism.