A number of important changes take place in the maternal uterine vasculature during the first
few weeks of pregnancy resulting in increased blood flow to the intervillous space. Vascular
endothelial and smooth muscle cells are lost from the spiral arteries and are replaced by
fetal trophoblast cells. Failure of the vessels to remodel sufficiently is a common feature of
pregnancy pathologies such as early pregnancy loss, intrauterine growth restriction and pre-
eclampsia. There is evidence to suggest that some vascular changes occur prior to …