Baby's Development in four stages.

@SmartDoctor1 ===================== Baby's Development. After the egg attaches to the uterus, some cells become the placenta while others become the embryo. The heart begins beating during week 5. The brain, spinal cord, heart, and other organs are beginning to form. At the eighth week the developing baby, now called a fetus, is well over a half-inch long -- and growing. A “full term“ delivery generally happens around 40 weeks. Prenatal development (from Latin natalis 'relating to birth') includes the development of the embryo and of the fetus during a viviparous animal's gestation. Prenatal development starts with fertilization, in the germinal stage of embryonic development, and continues in fetal development until birth. In human pregnancy, prenatal development is also called antenatal development. The development of the human embryo follows fertilization, and continues as fetal development. By the end of the tenth week of gestational