Ever wondered how do babies breathe in womb?
Babies are surrounded by amniotic fluid in womb, and they have lungs like us not gills like fishes. Then how do babies breathe in womb and not choke on amniotic fluid?
We know lungs don’t function in water and babies have no favorable conditions in their fetal life to breathe with the help of lungs.
Well there is a simple answer- BABIES DO NOT BREATHE IN FETAL LIFE.
YES! They never breathe until the moment of birth.
Remember that pat on the ass of a newborn? It is to make them cry to stimulate breathing by lungs. In fact is lungs are the last organ to develop in the fetal life.
Then how do babies breathe if not by lungs?
The function of lungs is done by umbilical cord in intrauterine life of the baby. Initially, the breathing process involves the blood vessels of the baby in the uterus that we don’t have as adults. There are extra blood vessels in the baby’s body in its fetal life that keeps the baby from needing lungs to process oxygenation.
What is umbilical cord?
Umbilical cord is a cord like structure attached to the placenta at one end and the baby’s navel at the other, with two arteries and a vein. It does the function of supplying oxygen and nutrients to the whole body of the baby.
What is a vein? No matter where it is – it brings blood to the heart not the oxygenated or non-oxygenated blood in it.
Artery? Has to take the blood away from the heart.
Where does oxygenation happen?
Oxygenation happens in the placenta.
Veins will take oxygenated blood to the baby’s heart and arteries will take the deoxygenated blood and waste products away from the baby’s heart back to the placenta.
After the umbilical vein, the vessel continues and goes through the liver and this little passageway is known as ductus venosus.
(Shortly after birth, it becomes the ligamentum venosum).
Blood in ductus venosus connects to the inferior vena cava that connects directly to the right atrium.
Foramen ovale between right and left atrium allows the oxygenated blood that comes into the right atrium to get shunted to the left side of the heart. After birth, it is shut and become fossa ovalis.
Ductus arteriosis is a passageway that takes blood away from the heart. It allows oxygenated blood that goes into the ventricle and then into the pulmonary trunk to get shunted directly to the aorta.
Aorta then distributed the oxygenated blood in the baby’s whole body.
Umbilical arteries (the branch of internal iliac arteries) are responsible for taking away the deoxygenated blood from the baby’s body bake to mother.
How do babies transition to breathing through lungs after birth?
Lungs are not used and are filled with the fluid. This fluid puts the pressure on the baby’s lungs. When the baby is going through labour, the compressive forces in the pelvis actually push that fluid out of baby’s lungs with every contraction. With less fluid in lungs, the blood vessels present in it open up, as that happens they become large by retaining more oxygen, one of the extra blood vessels that baby had in its fetal life close that was responsible for keeping the blood going to the lungs. The air starts going preferentially to the lungs. When baby is delivered, it craves for oxygen and takes long breaths.
Lungs then expand and retain more and more oxygen and supply it to the organs.