Maternal Nutrient Restriction in Pregnant Guinea Pigs Impacts Fetal-Placental Growth and Oxygenation

Maternal nutrient restriction (MNR) in guinea pigs results in placental structural abnormalities that reduce nutrient transport contributing to fetal growth restriction (FGR). However, whether fetal oxygenation is also reduced as a further mediator of altered growth and development remains unknown. Guinea pig sows were fed ad libitum (Controls) or 70% of the control diet pre-pregnant switching to 90% at mid-pregnancy (MNR). Animals were necropsied near term for fetal-placental growth measures, blood metabolites, and markers of tissue hypoxia and oxidative stress. MNR resulted in FGR with brains that are large and livers that are small relative to body weight which suggests a degree of blood flow redistribution. FGR-MNR fetuses showed increased levels of hypoxia related markers in a tissue and sex specific manner, and decreased makers of oxidative stress. Together these results implicate hypoxia as a mechanism for aberrant growth and development and evidence for protective adaptations with MNR induced FGR