“Personhood continues to be a topic of international debate and has been questioned critically during the abolition of human and nonhuman slavery, in debates about abortion and in fetal rights and/or reproductive rights, in animal rights activism, in theology and ontology, in ethical theory, and in debates about corporate personhood and the beginning of human personhood.” Source : Wikipedia
The philosophical question as to when (during the course of biological development) does a growing human fertilised egg become a 'person' has been debated for at least 2,000 years.
It's complicated by the lack of a generally agreed philosophical answer for the definition of a 'person'.
The question is an example of the Sorites Paradox - which points to the inherent vagueness associated with judging 'categories' - e.g. when does a heap of rice cease to be a heap if one removes one grain at a time.