OP 51 Fetal cholesterol deprivation in IUGR is caused by lower fetal synthesis rates

Abstract

Introduction Fetal cholesterol levels are low in IUGR. Objectives We aimed at analyzing fetal cholesterol precursors, oxidation products, and plant sterols to gain deeper insights into fetal cholesterol metabolism in IUGR. Material and methods Umbilical cord sera were sampled from fetuses delivered between 24 weeks of gestation till term. 49 IUGR fetuses were matched to 49 adequate for age delivered preterm and term neonates (CTRL) according to gestational age at delivery. Sterols were analyzed by GC?MS. Concentration levels were accomplished by apolipoprotein profiling and discussed at the background of a lower cholesterol acceptor capacity in IUGR. Results In the IUGR group, total cholesterol concentrations were about 20% lower when compared to CTRL (p 0.50), while in the CTRL group phytosterol levels were correlated to HDL-cholesterol (rho > 0.50) and ApoA1 (rho > 0.40) underlining the important role of HDL, apoA1 and apoE as a cholesterol acceptors at the fetoplacental interface. 24- and 27-hydroxysterol to cholesterol ratios were higher in IUGR as compared to CTRL (p Conclusions The data suggest that fetal cholesterol synthesis rates is balanced in the HMG-CoA reductase pathway and in the Kandutsch-Russel pathway. The Bloch-pathway is activated in IUGR possibly to counterbalance higher cholesterol turnover rates. However, one cannot exclude additional desmosterol (or precursors) supply by the mother. Of interest, plant sterols in IUGR are highly correlated to apoE underlining the role of apoE as an important cholesterol acceptor at the feto-placental interface. Understanding the fetal cholesterol metabolism is important at the background of new therapy strategies, for example statin treatment in preeclampsia.