The birth process took millions of years to be developed. It must allow 4 major reactions: a passage from an immunologically protected environment to the external environment, the acquisition of microbes in its digestive system, the transition from a temperature of 38 ° to colder external temperatures and especially the evacuation of the water molecules from the pulmonary alveoli to breathe.
This huge stress results in an impressive release of catecholamines -adrenaline and other stress molecules- at much higher levels than the most severe stress of the adult. In fact, we couldn’t tolerate such levels. This phase is extremely vulnerable and it is not surprising that many neurological and psychiatric diseases are born during this stage.
In a work from 2014, we were able to show that a hormone called oxytocin, which triggers labor, also has a protective effect on neurons, making them more resistant to episodes of absence of oxygen that can happen and cause many neurological diseases severely disabling. Even more surprising, a Swedish study shows that babies born by caesarean section have more pain (due to a blood test) than babies born vaginally, raising the possibility that this is due to the hormone. An experimental study in animals confirmed this hypothesis and allowed us to show that in the absence of this hormone, the pain is stronger. In other words, the same hormone triggers childbirth, has protective effects on the neurons and produces an analgesia to reduce the pain that has necessarily happen when we are born -even if we have no memory of that. Nature has incredible resources to use the same mechanism for different purposes ! The elegance of the underlying mechanisms and the implications of this type of study on the field of maturation and brain development diseases could be the topic of a new article.