Fetus
Prenatal organism between the embryonic state and birth / From Wikipedia, the free encyclopedia
This article is about the stage of prenatal development. For other uses, see Fetus (disambiguation).
"Foetus" redirects here. For the band, see Foetus (band). For the film, see Foetus (film).
A fetus or foetus (/ˈfiːtəs/; pl.: fetuses, foetuses, rarely feti or foeti) is the unborn offspring that develops from a mammal embryo.[1] Following embryonic development, the fetal stage of development takes place. In human prenatal development, fetal development begins from the ninth week after fertilization (or eleventh week gestational age) and continues until the birth of a newborn. Prenatal development is a continuum, with no clear defining feature distinguishing an embryo from a fetus. However, a fetus is characterized by the presence of all the major body organs, though they will not yet be fully developed and functional and some not yet situated in their final anatomical location.