title: Comparison of macronutrient concentration of preterm human milk between two milk expression techniques and two techniques for quantitation of energy.
abstract: Generally, when newborns in intensive care units receive human milk, we do not know the quantity of nutrients in that milk because such analysis is time-consuming and expensive. In our study, however, we sought to compare fat, protein, lactose, and energy concentration of a three-times-a-day sampling with a 24-h expression and to measure the difference between the calculated energy yield from protein, fat, and carbohydrate measurements and bomb calorimetry. At 14-18 days postpartum, 20 mothers of premature infants (30-34 weeks' gestation) expressed milk three times a day: 8 a.m., 12 p.m., and 8 p.m. At these three times, each mother expressed 3-5 ml of fore-milk and 3-5 ml of hind-milk for the sampling; the result was pooled for a 24-h expression. Only fat concentration differed significantly between fore- and hind-milk samples. Protein, fat, lactose, and energy concentration did not differ significantly between the two collection methods, 24-h expression and sampling. Moreover, we found no significant difference between the calculated number for energy content and the bomb calorimetry method of energy determination. The average fore- and hind-milk samples at 12 p.m. matched the 24-h milk expression. For clinical use, a milk sample obtained around 12 p.m. can predict macronutrient concentration, therefore allowing us to calculate an infant's approximate nutrient consumption.
mesh_terms: D002151:Calorimetry / Q000379:methods*; D002940:Circadian Rhythm; D005223:Fats / Q000032:analysis; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007785:Lactose / Q000032:analysis; D008894:Milk Proteins / Q000032:analysis; D008895:Milk, Human / Q000032:analysis*; D013048:Specimen Handling
chemical_list: D005223:Fats; D008894:Milk Proteins; D007785:Lactose