The composition and concentration of umbilical cord plasma lipoproteins; their relationship to the birth weight and other clinical factors of the newborn.

The present studies confirmed that plasma obtained from individual umbilical cords contains very low density, low density and high density lipoprotein particles whose mean compositions are similar to those of the adult, though they are present in considerably lower concentrations. A fairly wide variation in both composition and concentration was found between different individuals. For full-term deliveries, a positive correlation (p less than 0.01) was found between the cholesteryl ester: free cholesterol ratio of the high density lipoprotein fraction and the birth weight, suggesting differences in the distribution of the particles that constitute this lipoprotein fraction. Otherwise, no correlation was found between the composition or concentration of any lipoprotein fraction and birth weight, gestation, sex or other factor investigated. Premature newborns (30-36 weeks) had concentrations of high density lipoproteins and cholesteryl ester: free cholesterol ratios of the high density lipoprotein that were markedly high in relation to their birth weights and in the same range as full-term newborns (37-40 weeks).