Based on the relevance of breastfeeding for maternal-infant health, it is necessary that the prospective and longitudinal studies carried out in Mexico be analyzed as a whole in order to create an analytic model and to develop an institutional intervention program concerning the mother's risk of not starting or of abandoning lactation. To create this program all the factors which can be modified must be taken into account in order to make sure the mother has the elements to make a decision. The National Institute of Perinatology has developed a research program about lactation that consists of 3 studies that have been carried out since 1983. The general aim of these studies is to understand the breastfeeding phenomenon in an integral way considering the role of the institution as an educational instrument and a means of providing health support. These studies were based on different perspectives, approaches and times but had similar objectives. For this reason it is desirable to analyze them as a whole in order to obtain new considerations and temporal projections. In order to integrate the 3 studies a database will be created and then an analytical model (from a multivariate analysis) will be generated from the 1st study (by temporal order) which will be tested in the 2nd study making the pertinent modifications and finally it will be applied in the 3rd study. At the same time it will be necessary to group the variables into 2 classification systems: The first according to the temporal proximity with regard to lactation and the second according to the organization level to which they belong.