“When we are in our mother’s womb, our lungs do not function.”
Babies’ lungs exercise via simulated breathing movements.
“There is no respiration”
There absolutely is respiration.
Not through the lungs. They are the last to develop and the biggest difficulty to overcome in premature births.
Fetal hemoglobin is unique and carries a very high O2 content. Much higher than after birth and throughout life.
Oxygen is transferred from the mother to the fetus through the placenta, an organ attached to the uterine wall, which facilitates gas exchange without mixing their blood supplies. Maternal blood releases oxygen into the intervillous space, which then diffuses into the fetal capillaries within the placenta, moves through the umbilical vein, and enters the fetal circulation.
That is fetal respiration. Not through the lungs.
What is called “fetal breathing is a flow and pumping of amniotic fluid. Amniotic fluid contains very little O2.