Over the past century, profound technological, societal, and cultural transformations have significantly influenced various aspects of life, particularly the structure of families and the notion of parenthood. Fifty years ago, global concerns centered on measures to control birth rates due to fears of overpopulation. Today, policymakers are addressing efforts to counteract declining population growth that could potentially become unsustainable. This chapter explores historical events that precipitated this shift and examines whether reversing certain factors may help sustain human fertility above replacement level.