[Role of growth factors and insulin during pregnancy].

Growth factors represent different classes of polypeptides with insulin-like and mitogenic properties, known to stimulate cellular growth and metabolism. During pregnancy, insulin, insulin-like growth factors (IGFs), EGF, and PDGF are more specifically involved in the development of the fetoplacental unit. These peptides have specific receptors in the placenta and in various fetal tissues, which initiate metabolic and mitogenic effects. In addition, the placenta plays an active part in the regulation of IGFs secretion throughout pregnancy. Several lines of evidence suggest that growth-factors would be active to enhance the proliferative phase of feto-placental growth (14-24 semaines) while insulin would rather stimulate latter metabolic events (30-40 semaines).