We sought to examine the placental oxygenation status in a guinea pig model of intrauterine growth restriction (IUGR). We measured T2* in placentae of IUGR and control fetuses during a maternal oxygen challenge, where imaging was performed at both 20% and 100% inhaled oxygen. IUGR was defined by an elevated brain to liver volume ratio, indicative of blood flow redistribution secondary to fetal hypoxia. No significant difference in ΔT2* was observed, indicating that the placentae of the IUGR fetuses were not hypoxic. Thus we concluded that placental hypoxia is not necessary to induce fetal hypoxia in the guinea pig.