ABSTRACT
In vitro data on the morphogenesis of the human fetoplacental vascular system are rare due to a series of problems unique to the placenta: – Normal angiogenesis in placental villi requires the presence of an intact maternal
circulation surrounding the placental villi, an intact circulation within the villi, and the presence of a pO2-gradient between these circulations. Since all three conditions need to be kept constant for several days, to observe the process of vasculogenesis and angiogenesis, such prerequisites have thus far been impossible to attain in vitro, either with villous explants or perfusion of the organ.
