A prospective study of urinary proteins in early infancy

Acta Paediatr Scand. 1979 Sep;68(5):663-7. doi: 10.1111/j.1651-2227.1979.tb18435.x.


Urinary concentrations of protein, albumin, beta 2-microglobulin, alpha-amino nitrogen, and creatinine were determined in forty-one full-term infants on seven occasions up to six months of age. Except for beta 2-microglobulin the concentrations were highest on the first day, followed by a rapid decrease to a constant level within two weeks. Protein diminished approximately seven-fold, albumin twenty-fold, alpha-amino nitrogen three-fold and creatinine five-fold. By contrast, beta 2-microglobulin, a low molecular weight protein, first increased three-fold between day 1 and day 5, thereafter decreasing slowly 17-fold during the first three months of age. The data indicate that different kidney functions mature asynchronously.

MeSH terms

  • Age Factors
  • Albuminuria
  • Creatinine / urine
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Kidney / growth & development
  • Kidney / metabolism*
  • Male
  • Nitrogen / urine
  • Prospective Studies
  • Proteinuria*
  • beta 2-Microglobulin / urine


  • beta 2-Microglobulin
  • Creatinine
  • Nitrogen