The impact of maternal excess glucocorticoid exposure on rat placental vascular structure and function

This thesis developed novel applications for micro-computed tomography and magnetic resonance imaging, to reveal vasculature of the fetal side of the placenta, and placental oxygenation, in three dimensions. These approaches identified new mechanisms by which glucocorticoid excess results in fetal growth restriction (FGR) in a rat model. In rat FGR, reductions in placental and fetal weight were seen late in gestation, yet placental oxygenation was adversely affected earlier in pregnancy. Therefore, placental dysfunction precedes weight changes. This thesis has established novel technical methods which can be applied to other experimental models as well as for predicting and diagnosing human FGR.