Maturation of breathing.

In summary, although the basic mechanisms involved in the control of breathing during fetal and neonatal life are similar to those investigated more extensively in adult subjects, there are some aspects that make this control unique at this age. First, sleep seems to have a very profound effect during this period of life, particularly in the fetus, in which breathing is allowed to occur only during REM sleep. Second, in utero breathing activity is present since early gestation and without apparent reason, since it is not responsible for gas exchange. Being the lung of the fetus, the placenta is responsible for gas exchange. The purpose of fetal breathing must therefore be discovered. Third, the discovery of fetal breathing is probably the most exciting contribution made in this area during the last 50 years. To learn why this episodic breathing in utero becomes continuous after birth is the major challenge of the moment. Trying to understand this change at birth may result in the discovery of key mediators that are at the heart of the mechanism controlling breathing in general.