Compensatory Feto-Placental Upregulation of the Nitric Oxide System during Fetal Growth Restriction

BackgroundFetal Growth Restriction is often associated with a feto-placental vascular dysfunction conceivably involving endothelial cells. Our study aimed to verify this pathogenic role for feto-placental endothelial cells and, coincidentally, demonstrate any abnormality in the nitric oxide system. MethodsPrenatal assessment of feto-placental vascular function was combined with measurement of nitric oxide (in the form of S-nitrosohemoglobin) and its nitrite byproduct, and of the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine. Umbilical vein endothelial cells were also harvested to determine their gene profile. The study comprised term pregnancies with normal (n = 40) or small-for-gestational-age (n = 20) newborns, small-for-gestational-age preterm pregnancies (n = 15), and bi-chorial, bi-amniotic twin pregnancies with discordant fetal growth (n = 12). ResultsUmbilical blood nitrite (p ConclusionFetal growth restriction is typified by increased nitric oxide production during pregnancy and after birth. This response is viewed as an adaptative event to sustain placental blood flow. However, its occurrence may modify the endothelial phenotype and may ultimately represent an element of risk for cardiovascular disease in adult life.