The following essay aims to investigate Martin Heidegger’s notion of Dasein in Being and Time by taking into account the therein neglected existential-ontological aspect of birth. The point of departure is the concept of grundsein, i.e. Dasein being handed over itself as itself, groundlessly, with the remaining task of becoming its own basis from which it is able to properly project itself. In Being and Time this is made possible by actively grasping and appropriating ones ’ownmost possibility’ of being-towards-death. The present investigation however, raises the question whether or not Daseins other fundamental limit of being, namely birth, which in Being and Time is continuously disregarded, can provide a different understanding of grundsein; complementing the existing analysis by giving Dasein a more thorough framing. As for the proposed supplementing theory, the essay first turns to the concept of natality as it is developed in Hannah Arendt’s The Human Condition. Thereafter it traces the notion of birth as it unfolds in the work Relating Narratives by the contemporary Italian philosopher Adriana Cavarero, who thematically remains close to Arendt, although not without some crucial differences. With that in mind, the essay finally returns to Heidegger for a critical exploration of the theories opposed.  The present investigation aims to show that these theories of birth does in fact offer insights that are foreign to, albeit not irreconcilable with, the framework of Being and Time. Especially regarding that of mitsein, coexistence, which nonetheless also have inevitable consequences for the question of grundsein. By taking birth into consideration existentially, this essay seeks to shed light on what can be considered fundamentally relational aspects of Dasein as it is shown to be constitutively in-front-of, and a being-from-others. Furthermore there is shown to be an aspect of passive reception to Dasein, more specifically the non-negotiable gift of existence at all which unceasingly remains out of it’s reach; that is, arguably, somewhat overlooked in Being and Time (even though the concepts of thrownness and historicity may indicate such a condition). Lastly the author wishes to embed the existential-ontological matter of birth in the pressing planetary crisis of our time, asserting that the question of (human) birth and existence no longer can afford to ignore these biological-ecological aspects that are undeniably of due importance for the question at hand.