[20 years of research in epidemiology of human reproduction]

During the last two centuries, humanity has gone through two major transitions:first a demographic transition and second an epidemiological transition. In this moving environment, attention has been placed on a better understanding of the conditions of human reproduction. The role of epidemiology, a quantitative discipline, situated at the interface between biology, medicine and social sciences, has largely contributed to favoring advances in knowledge and rational use of data, with the aim of improving the health of the general population. Inversely, the new problems involved in the complex situation of human reproduction, of which using two individuals as the basic statistical unit for procreation is not of the least importance, have certainly contributed to the advancement of epidemiology.