The fetus develops in the uterus, according to The Columbia Encyclopedia. Inside the uterus, a sac of amniotic fluid protects the fetus and allows it to move. The fetus gets its nutrients and oxygen from the placenta and umbilical cord.
The Columbia Encyclopedia states that the term fetus is applicable at around seven to eight weeks after sperm fertilizes an egg. Before then, the unborn offspring is known as an embryo. The typical period of gestation for the fetus is 36 weeks. A premature birth occurs if a fetus comes into the world before this period of time is over. Many babies survive after premature births, particularly with the presence of artificial support.