The republic of Ireland retains a high degree of demographic singularity in Europe owing to the exceptional level of its birth rate and of the fertility rate among married women. However important changes are becoming more and more obvious in the evolution of the Irish population. First of all, since 1971, the net balance of international migrations has been heavily positive, so that the population is now strongly increasing. This increase is paralleled by a younger age structure which emphasizes the trend towards a higher marriage rate and a lower average age at marriage. But these changes largely compensate the big drop in the fertility rate of married women (— 30 % in 10 years time) which is hardly revealed by general fertility and birth...