The challenges of medical demography have become a major issue today in France, mainly because of the conjunction of two phenomena. Namely, a massive retirement of the “baby boom” generation and a delay in the medical training induced by the “numerus clausus” that had not anticipated that phenomenon. Unfortunately, the repercussion of the population ageing on hospital consumption and consequently on medical demography is very poorly integrated into the calculation and implementation of the medical professions’ numerus clausus in 2010. Thus we suggest a model that not only identifies the effective demand for care on operational geographical scale, namely, the health territory, but that also makes a projection of healthcare consumption based on the age of population of each “health territory” in a T+1 future. To illustrate this model, we take as example the obstetricians’ activity in France.