Have you ever wondered what makes some women give birth to their babies in week 38 and others do in week 41? Have you ever wondered what is the sign that indicates that the baby should be born? Because there are those who think that it is the body of the mother who says that it is time and there are those who think that it is a matter of the baby and, under normal conditions, it's the seconds that are right.
Researchers at the Southwestern Medical Center of the University of Texas (USA) have discovered with their experiments where the signal that starts the delivery comes from, that is, they have found the beginning of everything, the red button of "Childbirth", and not it's in the mother, but in the baby, that born thanks to his lungs.
Apples do not fall until they are ripe
When does an apple fall? Well, when she's mature. Some before, others later. The same thing happens with babies: they are not born until they are prepared and that is why there are more and more reluctance when it comes to causing births in this or that week. And when is a baby ready to be born? Well, when he is prepared to live abroad, when his organs are mature enough and, above all, when he is able to breathe. That is, it is the lungs that say when they will be able to perform their function perfectly and it is they who say when a baby may or may not yet be born.
And when are they mature? Well, at the moment they have enough surfactant. Pulmonary surfactant is a substance that we all have in our pulmonary alveoli whose mission is to allow breathing. To delve deeper into the subject, the alveoli are like little bags that empty when they breathe out and since at that moment they are practically without air, they could collapse (join one wall with another) and make the next inspiration difficult. Well, the surfactant prevents that from happening.
SRC-1 and SRC-2 proteins
For the discovery they made several experiments with mice. With them they found two proteins, SRC-1 and SRC-2, which control the genes of the pulmonary surfactant. Until moments before birth they are not activated, thus preparing the lungs for outside life and promoting the onset of labor.
Another factor that affects the time of delivery is the platelet activator (PAF). This factor increases the concentration of platelets in the fetus, also to prepare it for your baby's life. However, it seems that it does not affect so much at the time of giving the signal because when some mice were reduced this factor, the delivery happened about 12 hours later (which is equivalent to one more week of pregnancy in humans).
Now, what happened when they inhibited the function of the two proteins discussed and, consequently, the lungs did not have enough surfactant? Births were delayed an average of 38 hours, equivalent to about 3-4 weeks of pregnancy in a woman.
And how does all this happen?
In the last days of maturation of the fetus, the SRC-1 and SRC-2 proteins begin to cause an increase in surfactant secretion in the lungs and, at the same time, the platelet activating factor starts up. This increase It is reflected in the amniotic fluid, where the concentration of these substances increases. The uterus must be sensitive to it, because the consequence is that an inflammatory response of the same occurs and thus begins the delivery.
In any case, to better understand this process, researchers have already explained that they will study everything that happens next. That is, they know what activates childbirth, but they want to understand well how the message of the fetus passes to the mother.
Could this help prevent premature births?
That is the intention. The majority of neonatal deaths are in premature babies. In addition, being born before implies sometimes having maturational problems, needing some interventions and being born, in short, with a more or less clear disadvantage with respect to babies born at term. Everything that can be done to avoid it is welcome.
Researchers are suggesting that thanks to their discovery they will be able to know exactly how childbirth is triggered and in that way, in the future, to be able to somehow control the levels of these proteins to avoid premature births. Come on, that just as they delayed the deliveries of mice, they could do the same, perhaps, with humans. Obviously, this is nothing more than a hypothesis ... then we must see if there is any implication to this solution, that is, see that the remedy is not worse than the disease.
Meanwhile, while all these investigations arrive, ordinary mortals benefit from increasing our general culture. Now we know how labor is triggered.
