In pregnancy disorders, such as intrauterine growth restriction (IUGR), a poorly functioning placenta is a major component of the disease process. Placentae from IUGR pregnancies often have poor vascular development, which limits their ability to absorb nutrients from the maternal blood. While IUGR affects 8-14% of pregnancies, we currently have no effective treatment for this disorder. Mesenchymal stem cells (MSCs) have shown exciting therapeutic promise in regenerating a range of tissue types, in part by stimulating blood vessel development. This research aims to determine whether MSCs could be a viable treatment for IUGR by determining: (1) whether IUGR is associated with differences in placental MSC function; (2) whether transplanted MSCs can survive in placental tissue; and (3) how MSCs may contribute to successful placental vascular development. This will allow us to determine whether MSCs could be successfully transplanted or targeted therapeutically to fix failing placentae from the inside out.