LIPID METABOLISM IN THE NEWBORN

Abstract

Triglyceride, cholesterol and cholesteryl ester concentrations in the cord serum of 10 infants were determined and found to be considerably lower than in the mother's serum. The fatty acid compositions of the cord serum triglycerides and cholesteryl esters were significantly different from those of the mothers. The linoleate fraction of these esters was especially low. Plasma triglyceride concentrations in full-term, healthy infants rose significantly 9 hours after birth. The fatty acid distribution of these triglycerides at 12 hours varied from that at birth; this difference was also reflected in reported plasma free fatty acids and suggests a precursory relationship. The plasma total cholesterol concentrations did not alter in the first 12 hours, nor did the fatty acid distribution of the cholesteryl esters change significantly. A method to measure low concentrations of triglycerides in small samples is described. The differences between maternal and cord serum lipids suggest that fetal lipids do not originate directly in the mother. The rise in plasma triglycerides is part of an increased fat mobilization occurring after birth.