Studies in cholestasis of pregnancy. III. Fatty acid composition of serum phosphoglycerides.

The influence of cholestasis of pregnancy (CP) on liver lipid synthesis as reflected by the composition of serum phosphoglycerides was studied in 28 pregnant women in the last trimester by means of gas-liquid-chromatography (GLC). All patients complained of pruritus and had immunologically detectable lipoprotein-X (LP-X) in serum. Twenty women with uncomplicated pregnancies served as a control series. In lecithin, low palmitic acid (16:0) and high oleic acid (18:1 (n-9)) were found which appear to be characteristic for CP. The increased oleic acid suggests an enhanced liver lecithin synthesis through the cytidine-diphosphate diglyceride pathway. Measurement of the concentrations of lecithin from the gas-liquid-chromatograms was made possible by the use of an internal standard fatty acid added, which gave a linear relation to direct determination of lecithin. For further studies of influences of cholestasis of pregnancy on the relative fatty acid composition, lecithin was chosen because differences between lecithin (PC) and phosphoglycerides (GPL) were found, evidently due to mutual variations among the three components in GPL (lecithin, cephalin and lysolecithin).