MRI Assessment of Placental Health

The ultimate goal of this project is to develop methods that allow informed decision-making on the delivery time of fetuses that are at increased risk of stillbirth due to IUGR. In placenta related IUGR pregnancies, there can be multiple concurrent placental pathologies. Although there is no specific correspondence between a single type of pathology and IUGR, the common result of these pathologies is placental insufficiency, which limits the maternal-fetal exchange. Oxygen and nutrition transport is known to be hindered in IUGR placentas due to obstructed or abrupt vasculature, massive fibrin deposition, and inflammation in the villous and intervillous space (villitis). Thus one potential approach to distinguish IUGR pregnancies from normal ones is to assess the efficiency of placental transport. Based on the hypothesis that efficiency of oxygen transport is representative for overall oxygen and nutrition transport in placenta, the investigators propose to characterize the blood oxygenation and blood perfusion in placenta in vivo via MRI, and use it as an index for better stratification in the IUGR risk group. The investigators will also consider alternative MRI approaches such as structural, diffusion and spectroscopy measurements inside the placenta, which might reflect the state of placental transport and reveal the status of placental health. Specific aims: 1) To correlate the MRI metrics that differentiate placental insufficiency from normal placenta transport with histopathology data of the placenta. 2) To correlate the MRI metrics that reflects placental insufficiency with fetal outcome