All living things come from Papatuanuku. She is the foundation from which vitality is conceived. Considered the womb of life, she is the whenua (land), which gives birth to all living things and the place, the soil, to which these things return. She is the Ukaipo, the precious and cherished nurturer of humanity - the supreme mother whose earthly body provides sustenance and nourishment to all her earthly children. As a living breathing organism, she controls her own biological processes.
Women and Papatuanuku are physically and spiritually aligned because in terms of a traditional Maori view point, their wombs are seen as the same. Both hold the nurturing waters that give birth to humankind.
The process of burying a woman’s placenta and pito (umbilical cord) is hugely significant as it represents one’s devotion to Papatuanuku and begins a lifetime relationship with their ancestral homeland. It also symbolises the acknowledgement of ones entrance or manifestation into the physical world.
(Excerpt from NIU - He Tangata Matauhi, Voices of our Ancestors)