The human placenta is a complex structure with unique capabilities. It has a 40-week average life span, during which it facilitates the exchange between the maternal and fetal cardiovascular systems. There is little known about the development and maturation of the placenta throughout the gestational period during normal pregnancy. It is however recognized that the placenta appears more heterogeneous on various imaging modalities as the pregnancy progresses. In this work, we propose to characterize the placenta heterogeneity as a function of gestational age through the application of grey-scale texture analysis to ADC maps using a large retrospective MRI database.