The placenta is a unique and transient organ that is essential for mammalian reproduction. It acts as a life-support system for the growing embryo and fetus, mediating nutrient, oxygen, and waste exchange with the mother. The progressive elaboration of this vital exchange interface throughout pregnancy, matches nutrient availability with embryo-fetal growth and allows delivery of well-developed offspring in eutherian mammals, sometimes after very long gestational periods. Impairments in the development of the placenta can lead to poor embryo-fetal growth or even demise. Our team are interested in whether molecular pathways that are dysregulated in human fetal growth restriction or preeclampsia, are expressed across placental development in other species, such as the mouse and lizard.