Sinding M, et al. – In this study, researchers explore the ratio of fetal weight estimated by ultrasound (EFW) to placental volume (PV) evaluated by magnetic resonance imaging (MRI) (EFW:PV ratio) in normal pregnancies and in those complicated by placental dysfunction. In normal pregnancies, the increasing EFW:PV ratio may reflect a higher placental transfer capacity per unit placenta in later gestations. Surprisingly, in pregnancies complicated by placental dysfunction, the EFW:PV ratio was higher than normal. Given the normal postnatal BW:PW ratio, this finding might simply indicate a decreased blood volume fraction in dysfunctional placentas. An increased EFW:PV ratio may be an in vivo marker of placental dysfunction.