BACKGROUND One of the fundamental arguments sustaining the classical demographic transition theory was that couples wanted to have a given number of surviving children, not a specific number of births. However, this cornerstone of transition theory came in for severe criticism in the wake of the results published in many studies linked to the Princeton European Fertility Project (PEFP). In recent years, studies using longitudinal microdata have made important contributions towards clarifying the relationship between mortality and fertility during the transition. OBJECTIVE We will show that aggregated data (from both the national and the provincial sphere) can lead to conclusions similar to those obtained at micro-level. METHODS Employing information from 25 developed countries, this article analyzes trends in net reproduction (rather than just the intensity of births) over a long period of time. We also quantify in detail the different influences of marital fertility, mortality, and nuptiality on historical developments in net total reproduction. RESULTS Our analysis reveals a great diversity in the reproductive patterns followed in different countries in the process of regulating the total number of births. We also detect the existence of a nonhomogeneous effect of mortality on net reproduction during the demographic transition. CONCLUSIONS There is little point in analyzing fertility trends if we leave out the mortality scenario that forms the background to these tendencies. CONTRIBUTION The results of this study using aggregated data (covering longer periods of time and larger geographical areas) are fully in line with those of recent projects using microdata from family reconstructions.