-a fetus is a human embyo after the development of the inner organs/the fetal stage of parental development starts when the major structures have formed and last until birth
->it starts in the 11th week of gestational age ;in the 9th week after fertilisation; before it is an embryo
embyo and fetus define by law: http://www.gesetze-im-internet.de/eschg/BJNR027460990.html
