The fetus in the mother continuously makes respiratory movements, starting from the second trimester of pregnancy. While it is the glottis firmly closed, to avoid getting amniotic fluid in unopened underdeveloped lungs. Simulation of respiratory movements during this period is nothing more than a chest workouts to work on providing the baby with oxygen immediately after birth.
Use your easy baby before birth is not able, as they are revealed only at the moment of his first cry. Children born prematurely may experience serious breathing problems as a special substance, a surfactant, providing the opening and the surface tension of the lung tissue, begins to produce fruit only at 34 weeks of pregnancy. There are special drugs that speed up the synthesis of this substance as well as artificial surfactant, but it only helps to survive in preterm children, without affecting fetal breathing.
Once the lungs are not involved in prenatal baby's breath, then breathe it in a completely different way. Already in the first weeks of pregnancy develops a totally unique organ, the placenta, providing the fetus with all necessary for life, including oxygen. Through the placenta oxygen is transferred from the blood system of the mother into the blood of her child. Actually, a pregnant woman breathes for two, it's her lungs fill with air are both of body.
The placenta is arranged in such a way that supports the baby comfortable existence, even in the case where the oxygen consumption of the mother for any reason is limited. That's why pregnant women have an increased tendency to fainting due to inadequate oxygen to the brain. In stuffy or smoky rooms of oxygen in the air is much less, and the volume of respiration remains the same, and to provide the child, the placenta takes oxygen to the detriment of the mother.