«Aging» of placenta

As the nature of any intrinsic biologic aging process or even of its existence independent of disease is unknown, it is impossible to state whether or not the placenta gets old. There are two main conceptions to describe the morphological and physiological changes of placenta at term. It is widely believed that during the relatively short duration of normal pregnancy the placenta progressively ages and is, at term, on the verge of decline into morphological and physiological senescence. Several placental functions decrease near term, but it is impossible to attribute these to aging. In fact, some of them may represent adaptive additional maturation or pathological processes. The genetic differentiation/invasion/maturation programs of placental cells could be modulated by their environment: oxygen, extracellular matrix, and soluble factors (cytokines, growth factors, and hormones).