Aim: To investigate the current concepts related to the definition of human viability in a historical perspective.
Methods: A review of the international literature was performed by using PubMed, Google, Embase to find definitions of Human Viability. The papers collected were divided chronologically.
Results: Over the years, many authors have debated the concept of the limit of human viability, starting from Ballantyne in the early 1900. The definition differs from author to author.
Conclusion: The definition of human viability is still under discussion. It depends primarily, but not only, on gestational age. A number of genetic, cultural, social and technological variables are also influential. This definition could have an impact on legislation and the widespread misunderstanding of this concept in the lay public could also be enhanced by a frank discussion among clinicians and other professionals.