FA composition of cholesteryl esters and phospholipids in maternal plasma during pregnancy and at delivery and in cord plasma at birth.

The purpose of this study was to assess the FA composition of both cholesteryl esters (CE) and phospholipids (PL) in maternal plasma during pregnancy and at delivery and in umbilical plasma at birth. A longitudinal study of 32 normal pregnant women was carried out with three cutoff points during pregnancy (first, second, and third trimester) and at delivery. Few significant differences occurred in the FA profile of maternal CE: 18:1n-9 increased, 18:2n-6 dropped slightly, and 18:3n-3 decreased with progressing gestation. In maternal PL, long-chain highly unsaturated FA concentrations dropped and were replaced by saturated FA as gestation progressed. Additionally, changes in saturated FA in PL occurred: Shorter-chain 16:0 was higher whereas longer-chain 18:0 was lower at delivery compared to early pregnancy. The FA profile of umbilical venous plasma was strikingly different from that of maternal plasma at delivery. Cord plasma CE contained more saturated and monounsaturated FA than maternal CE. The polyunsaturates 18:2n-6 and 18:3n-3 are lower in umbilical CE than in maternal CE whereas 20:4n-6 and 22:6n-3 are twice as high in umbilical CE. Cord plasma PL have a higher content of long-chain highly unsaturated FA than maternal plasma PL at delivery. In contrast to maternal plasma PL, 16:0 was lower and longer-chain saturated FA were higher in cord plasma PL. The FA profile of umbilical plasma at birth shows preferential accumulation of 20:4n-6 and 22:6n-3, with low concentrations of 18:2n-6 and 18:3n-3 in CE and PL, indicating a preferential supply of the fetus with long-chain highly unsaturated FA needed for fetal development.