the annual number of births has increased by 9 % for 10 years in metropolitan France, and the fertility indicator increased from 1,65 to 2,00 children per woman between 1993 and 2008. Contrary to what might be thought, these increases do not come from an increase in the fertility of couples from one generation to the next. Those of today have as many children as their elders thirty years ago. However, they were later, as this delay led to a temporary decrease in the fertility indicator and then to an upward trend.