Day 21	The heart begins beating.
Day 28	The backbone and muscles have started forming. The arms, legs, eyes and ears are now visible.
Day 30	The embryo has grown 10,000 times bigger than the original egg on the day of fertilization. The placenta, which forms a barrier keeping the mother's blood separate while allowing food and oxygen to pass through to the embryo, will be the its lifeline throughout the pregnancy.
Day 35	Five fingers are now visible on the hand. Pigment is produced in the eyes, causing them to darken.
Day 40	Brain waves can now be detected and recorded. The embryo is now able to feel physical pain.
Week 6	The liver has begun taking over the production of blood cells, and the brain begins controlling the movement of muscles and organs.
Week 7	The embryo begins moving spontaneously. The jaw is formed, including teeth buds in the gums.
Week 8	It is now referred to as a fetus, and is a little more than an inch long. The word "fetus" is Latin for "young one" or "offspring." The fetus now has everything present that will be found in a fully developed adult. The heart has been beating for over a month, the stomach is now producing digestive juices and the kidneys have begun functioning. Forty muscle sets have begun to operate in conjunction with the nervous system. The fetus' body will now respond to touch, although the mother will not be able to feel movement until sometime in the fourth or fifth month.
Week 9	The fetus now has uniquely identifiable fingerprints.
Week 10	The fetus can squint his or her eyes, swallow and wrinkle his/her forehead.
Week 11	The fetus is about two inches in length. He/she is able to urinate. Movements are more coordinated. The face has assumed the profile of a baby.
Week 12	The fetus now goes through periods of sleeping, waking up and exercising its muscles. It can open and close its mouth, turn its head, and curl its toes.
Week 13	Hair has begun to grow on its head. The sex of the child is now apparent.
Month 4	The fetus is 8-10 inches long. It can hear the mother's voice and heartbeat as well as sounds outside the womb.
Month 5	The fetus is about 12 inches long. The mother has felt the fetus move by now. A loud noise may startle the baby, causing it to jump.
Month 6	Babies born in this month, given the proper care, would survive.
Month 7	The baby recognizes his mother's voice.
Month 8	The skin begins storing a layer of fat underneath for insulation and nourishment, causing it to thicken.
Month 9	The baby normally weighs between six and nine pounds. His heart pumps approximately 300 gallons of blood per day. He is fully capable of living outside the womb without medical treatment.