PP033. Oxidized LDL particles in the placenta of intrauterine growth restriction (IUGR) subgroups

Abstract

Maternal serum LDL concentrations are lower in IUGR pregnancies as compared to controls (CTRL). We now hypothesized that an increased oxidative stress results in the formation of oxidized LDL (oxLDL) particles which than accumulates within the placenta. This is particularly hypothesized for the severe early onset subgroup of IUGR with preeclampsia (PE). OxLDL (minimal modified and fully oxidized LDL) levels in placental biopsies from term IUGR (>37 weeks, t-IUGR, n=5), preterm IUGR (<34 weeks, p-IUGR, n=5), and preterm IUGR with PE (PE-IUGR, n=5) were compared to a CTRL group consisted of gestational age matched preterm (p-CTRL, n=10) and term (t-CTRL, n=5) placentas by ELISA and immunohistochemistry (IHC). Fully oxidized LDL but not minimally oxidized LDL concentrations were higher in p-IUGR and tend to be increased in PE-IUGR when compared to p-CTRL (p=0.040 and p=0.075). There was virtually no difference of fully oxidized LDL levels between p-CTRL, t-CTRL, and t-IUGR. We confirmed a higher oxLDL accumulation in trophoblasts of p-IUGR and PE-IUGR as compared to both CTRL groups by IHC though this was not statistically significant. Conformational changes of LDL during the process of oxidation might lead to an accumulation of oxLDL particles in placental tissue of IUGR. The pathogenesis of early onset IUGR might differ from those of late onset IUGR.