RESUMEN
Background: There has been continuous debate among scholars regarding fertility transition in Africa. Two conclusions emerge: slow pace of decline because of weak facilitating social programs and high demand for large families amidst weak family planning programs. Accelerated fertility decline is expected to occur if there is both substantial decline in desired fertility and increased level of preference implementation. Despite these conclusions, there are also emergent exceptions in Africa, even among the Eastern African countries. Our motivation for the study of this region therefore lies in this context. First, the East African countries share some similarities in policy framework. Secondly, Rwanda and Kenya appear as exceptional in the drive towards accelerating further fertility decline. Fertility change therefore in any one country may have implications in the neighbouring country due to the commonalities especially in language, cultural traits, diffusion and spread new models of behaviour. Methods: With the utilization of DHS data, we analyse trends overtime in two specific features that scholars have indicated to slow or increase fertility decline. Using Bongaarts supply-demand framework, we first deduce trends in fertility preferences among women of reproductive age (15-49 years) and second, the extent to which women have been able to implement their fertility preferences during the course of fertility decline and subsequently decomposing these trends. Results: We found that with the rising aggregate of the degree of fertility preference implementation index, continuous declining trends in demand for births and subsequent increases in the contribution made by either or both the wanted fertility and the degree of fertility preference implementation index across categories that fertility transition is certainly on course in all countries albeit at different levels, thanks to the family planning. Conclusions: Family planning programs must therefore be accompanied by rigorous, consistent sensitization and public education.