Placental morphology: from molecule to mother -- a dedication to Peter Kaufmann -- a review

Theories on the development of placental pathologies and insufficiencies are based on the assumption that the development of the placental villous trees, the invasion of extravillous trophoblast or the differentiation of the villous trophoblast is somehow dysregulated. One of the pioneers trying to answer these questions is Peter Kaufmann, who started research on the placenta nearly 40 years ago. In this review, we try to shed light on various aspects of placental development, and on how important morphology is in combination with other disciplines to elucidate the differences between a normal and a pathological placenta.