Our results show that, in pregnancies complicated by gestational diabetes, PTH-rP and PTH-R1 are strongly expressed in extravillous cytotrophoblast and in the decidua, mildly expressed in the syncytiotrophoblast and in the villous cytotrophoblast, while no expression of these receptors was found in the villous stroma. The gene discussed is PTH1R; the disease is gestational diabetes.