subject: How Fetus Gets Oxygen [print this page] A fetus inside the mother is able to breathe by forming umbilical cord. It is known as the lifeline which starts from a line as thin as hair and then grows into an adult-finger thick with the length of up to 2 feet by the last month of pregnancy.
The lungs of the baby start to grow in the uterus for the first thirteen weeks. Then, the umbilical cord will grow. Normally, it is attached to the placenta of its mother. It is connected to the lining of uterine. It emerges from the stomach of the baby with three vessels including one vein and two arteries. Then, these vessels form connecting coils which are embedded in the jelly with thick cover. It resembles soft twisted rope.
The fetus gets the oxygen when its mother inhales. The oxygen will enter the blood of its mother through the heart and also lungs. The oxygen will go through the placenta and then into the tiny blood vessel in the fetus. The carbon dioxide from this respiration is then rid out of its body through the reverse way.
The heart of the fetus will pump its own blood by using the umbilical cord arteries which are attached to placenta. The finest branches of the placenta still lie in the blood of the mother. The umbilical vein will drain the branches. It takes the blood to the fetus and flow it back to the heart. Then, the used blood of the baby flows through the arteries and the fresh blood will be carried by vein to the heart of the fetus.
In addition, the placenta blood of the mother will form a lake which bathes the smallest vessels. Maternal blood is not like the fetal blood. It will flow into 80 up to 100 small and twisting uterine arteries which are empty into a five-ounce lake. In a minute, this blood is refreshed for around three and four times.
There are some rare cases in which the placenta detaches from uterus. It causes the fetus to receive low oxygen which can lead the baby to risk. Yet, there are only one percent of pregnant women who experience it. Usually, it happens for the last twelve weeks. Women over 35 years old who experience sickle cell anemia have greater risk of this detachment.
After the birth, the temperature of the baby will drop so that the jelly which covers the cord will collapse the vessels of blood within. It will create the natural clamp in five minutes. When the baby starts breathing, the circulation system and the heart will take over so that the baby can use its own lungs to get the oxygen.
