A fetus is an unborn human between the embryonic stage of development and birth. A fetus normally forms within eight weeks (ten weeks gestation) of conception, which is the very beginning of a pregnancy when a sperm fertilizes an egg. Approximately three weeks after fertilization, an embryo forms inside the woman's uterus. The embryo eventually forms into a fetus, a stage distinguished by the unborn baby's visibly human features such as arms, fingers, toes, and eyes. The fetal stage... więcej

Salem Press Encyclopedia of Health, 2022. 3p.