Placental hypoxia is associated to placental dysfunction and low birth weight. In vivo measurements of placental hypoxia may serve as biomarkers of placental dysfunction. The MRI time constant, T2* reflects placental structure and placental oxygenation. Placental T2* performs significantly better than the UtA PI in prediction of low birth weight. Placental T2* may be used as an in vivo biomarker of placental dysfunction.