Intrauterine growth restriction (IUGR) is associated with impaired placental metabolism and transport. Hyperpolarized carbon-13 (HP13C) MRI was used to detect metabolic differences between control and IUGR placentae in pregnant guinea pigs, and to determine the impact of maternal hyperoxygenation on placental metabolism. Area under the curve (AUC) was calculated for lactate, alanine, and bicarbonate and expressed as a ratio relative to pyruvate AUC. The ratio of alanine to pyruvate AUC decreased significantly in IUGR versus control placentae. Maternal hyperoxygenation resulted in significant increases in ratios of alanine and bicarbonate to pyruvate AUCs for both control and IUGR placentae.