Fetal Development(Writing chronologically)

Pregnancy continues to 38weeks Conception begins when a woman's egg is fertilized by a sperm. With a day, the egg begins to develop rapidly such as differentiation into a group of cells called a blastocyst. Since then, Blastcyst moves into uterus and has increased in size to hundreds of cells. Be the eighth day after conception the blastocyst has begun to attach to the wall of the uterus where it will grow at a rapid rate. Fetal development can be classified into 3 stages such as the first trimester, the second trimester and the third timester.

The first trimester refers to the period of 12weeks after conception. In 2 weeks after fertilization, the blastocyst is called an embro. At this time, the embryo is about 1/100 of an inch long. The embryo continues to grow and then it develops a head and a trunk at 4 weeks. Structures that will become arms and legs, called limb buds, begin to appear. A blood vessels forms which will later develop into the heart and circulatory system. At the same time, a ridge of tissue forms which will be brain and spinal cord. At 6 weeks, the heart has four chambers. Fingers and toes begin to form. Cells are starting to form the eyes, ears, jaws, lungs, stomach, intestines and liver. In 8 weeks, muscles and skeleton are developing. The fetal heartbeast can be detected with a heart monitor and fingers have nails at 10 weeks. Then 12 weeks, the fetus is about 3-1/2 inches and weighs about 2 ounces. The fetus begin to swallow, the kidneys make urine, and blood begins to form in the bone marrow. At this point the sex can be indentified.

The second trimester is from 14 weeks to 22 weeks of pregnancy. At 14weeks the skin appears transparent and a fine layer of hair begins to grow on the head. The fetus can blink, grasp and move its mouth at 16 weeks. At the same time the fetus begin to kick, although woman may not be able to feel the movement. In 18weeks, the woman may feel the fetus moving. At this time, if an ultrasound is performed, the parents may be told the sex. At least after 20 weeks, the fetus may have a little chance to servive outside the woman's body.

The last time of the second trimester, the fetus is about 8-1/4 to 8-1/2 inches and weighs about 1-1/4 pounds. The mother's sounds such as breathing, heartbeat and voice can be heard at this time. During the third trimester, the fetus grows fully to be delivered from the mother's body. At 24weeks, the fetus can respond to sound, wake and sleep. And the eyes are partially open and can perceive light at 26weeks. also 9 out of 10 babies will survive. At 28weeks, the fetus can open and close its eyes and suck thumb. Breathing and body temperature are controlled by the brain. Since then almost all babies will survive. In 32 weeks, the eyes are close during the sleep. And the skin is now pink and smooth. After 34weeks, the fetus can turn and lift its head. After that lungs are usually mature and fetus can grasp firmly. Also the fetus turns toward light sources at 36weeks. Finally, at 38weeks, the fetus is about 14inches and weigh from 6-1/2 to 10 pounds. At that time, a baby is full-term and reagy to be born.

Subsequently, those kinds of medical information in detail mentioned above may help woman to feel the mysteris of life whether she keeps pregency or consider abortion. In particular, if mother takes a medicine she can understand cleary its fetal effects to the fetus. As a result, each mother and a unborn child is unique. A pregnant woman as well as a fetus should be treated as a special life.