Plasma and red blood cell fatty acid of very low birth weight infants fed exclusively with expressed preterm human milk.

The fatty acid composition of plasma phospholipids, triglycerides, sterol esters, and red blood cell phospholipids were determined at birth and again on d 7, 14, and 28 of life in 22 very low birth weight infants (birth weight 1180 +/- 290 g, gestational age 29.8 +/- 2.4 wk) fed exclusively with preterm human milk starting from the first hours postpartum. Milk intake was recorded daily, and intakes of fat and individual fatty acids were measured weekly. The intakes of linoleic acid and linolenic acid rose significantly during the study period, so did their incorporation into plasma and red blood cell lipids. The intakes of arachidonic acid (29.2 +/- 2.4 versus 30.4 +/- 2.1 mg.kg-1.day-1) and docosahexaenoic acid (18.8 +/- 1.7 versus 17.0 +/- 1.2 mg.kg-1.day-1) on d 14 and 28, respectively, were not different; however, their plasma levels declined significantly. The percentages of arachidonic acid declined in all plasma and red blood cell lipids, whereas the fall of docosahexaenoic acid was more notable in triglycerides and sterol esters, intermediate in plasma phospholipids, and less pronounced in red blood cell phospholipids. We conclude that very low birth weight infants fed exclusively with preterm milk, which unlike most preterm formulas contains long chain polyunsaturated fatty acids, exhibit declining levels of arachidonic acid and docosahexaenoic acid from birth up to 28 d of life.