Macromolecular Absorption in Preterm and Term Infants

ABSTRACT. Human o-lactalbumin (α-LA) has been used as a marker for measuring macromolecular absorption. The serum concentration of human α-LA after a human milk feed has been studied in 32 healthy very low birthweight infants (VLBW), fed human milk (gestational age 26–32 weeks) and in 56 term, breast-fed infants, age 3–140 days. At 31 weeks of gestation the serum concentration of human α-LA was more than 10 times higher (mean value 3000 and median value 2101 μg/1 serum/1 human milk/kg body weight, n = 11) than in the term infants aged 3–30 days (mean value 257 and median value 152, n = 29). The serum concentration of o-LA decreased with increasing maturity in the VLBW-infants. At a postconceptional age of 37 weeks the values were similar (mean value 200 and median value 99, n = 8) to those found for term infants during the first month. In the term infants a decreasing absorption of α-LA was found with increasing postnatal age.