This chapter looks at fertility intentions, and more especially the factors linked to their non-realization. In half of all cases, persons who reported intending to have a child, did not in fact have one in the six following years. In many cases, childbearing plans thus appear to be either vague or impossible to realize. Certain circumstances (such as separation) may oblige people to rethink their plans, delay them or abandon them altogether. Plans are also redefined over the life course. In particular, age, conjugal status and number of children play a decisive role in realization of intentions. People who are young, in recently formed unions and childless tend to have a child later than planned, while those who are older and already parents of at least two children more often abandon their plans.