The purpose was to investigate the potential of bi-exponential model of diffusion-weighted (DW) signal decay to quantify diffusion and perfusion in healthy human placentas. The relation between diffusion and perfusion parameters with microstructural changes occurring during placenta development was also investigated. 26 pregnant women underwent DW examination. Apparent diffusion coefficient D, pseudo-perfusion fraction f and pseudo-diffusion coefficient D* were obtained in specific placental regions. The Pearson correlations between D, D*,f and clinical data (Gestational Age, Body-Mass Index and basal Glycaemia) were evaluated. D and f show to be good indicators of placenta morphological changes due to Gestational Age.