Our focus is on human placental development, and the involvement of the placenta in complications of pregnancy such as miscarriage, fetal growth restriction and pre-eclampsia. In particular, we are interested in the effects of oxygen, hypoxia, and oxidative and endoplasmic reticulum stress on trophoblast differentiation and function. This interest stems from our finding, in collaboration with Professor Eric Jauniaux, that the maternal arterial circulation to the placenta is not fully established until towards the end of the first trimester of pregnancy. We demonstrated that prior to this time the conceptus is supported by secretions from the endometrial glands, histotrophic nutrition, that are delivered into the intervillous space through the developing basal plate. Consequently early development takes place in a physiologically low oxygen environment, and there is a threefold increase in the intraplacental oxygen concentration at the start of the second trimester, the oxygen transition. Currently, we are investigating how the placenta may stimulate its own development during early pregnancy by signalling to the endometrial glands and upregulating their secretion of growth factors and nutrients.