Urinary β2 microglobulin in the newborn

. Twelve full-term, healthy newborn infants had daily urinary β2 microglobulin, albumin and creatinine levels measured during the first five days of life. A marked elevation in urinary β2 microglobulin was demonstrated. There was a marked variation from day to day with a range of 20–11,000μg/l. The relatively steady creatinine and albumin excretion levels suggest there is a true increased excretion of β2 microglobulin in the neonatal period with a tendency for the excretion rate to rise during the first five days of life.