Years ago, when deliveries occurred in homes, the due date was less specific than now. There was talk that the birth would be "at the end of the summer", "for Christmas" or "for Easter", for example.
When the delivery moved from home to the hospital, it began to talk about "Estimated due date" or "probable due date" when, according to some experts, the best thing to do would be to speak of a "probable week of childbirth", 40 weeks after the date of the last menstruation or 38 weeks after conception.
The formula for calculating the probable due date (FPP) is very simple. It's called Naegele's rule. The date of the first day of the last menstruation is taken and 7 days plus 9 months (or less 3 months, as you prefer) are added. Or what is the same, you add 40 weeks or 280 days.
But the probable date of delivery is just that, probable. It is the day calculated following this formula, it is an approximate date that may have a margin of error of up to 14 days before or after the calculated day.
The ultrasound will help to refine the date because the images check if the weeks of pregnancy coincide with the size and development of the baby. But this will be possible during the first trimester, when all babies develop more at least at a similar rate. As the pregnancy progresses, although they have the same gestational age, each one begins to manifest its particular growth signs, some are larger than others, some weigh more, or have the largest cranial perimeter, larger bones, etc. .
However, children do not know about mathematical formulas. They are born when they have to be born, although some arrive in the world when others have it. It shouldn't be that way, but it happens.
I know babies who were born promptly on the day of the calculated due date, but this occurs in only 10% of cases. The remaining 90% is born as provided by hormonal and endocrine changes of the mother and baby responsible for triggering labor.
There are those who consider that the forces of nature such as tides, storms or moon phases interfere with the date of birth, but they are only beliefs without scientific foundation.
More rigorously, some experts say that psychic aspects influence the onset of labor. They claim that there is an interaction or attunement between the mother and baby's brain. That the latter would send endocrine signals to the placenta and the mother so that her body starts the segregation of oxytocin, a hormone responsible for causing uterine contractions that give rise to birth.
Be that as it may, a child is considered born at term when the delivery occurs between the 37th and 42nd week of pregnancy, taking into account the margin of plus or minus 2 weeks that could have been error in calculating the date of delivery.
Before week 37 it is considered a preterm or premature delivery. If the child is born between week 35 and 37 we are talking about a moderately premature baby, between week 30 and 34 we talk about a very premature baby and before week 30 of large premature babies.
For its part, it is called post-term delivery when it occurs after week 42. At this point the vital signs of the baby are constantly controlled to prevent fetal suffering from occurring. If you notice any minimal indication, the doctor will take action on the matter.
Whatever day your baby arrives in the world, it will be an extremely important date in your lives. In this Special on Childbirth we will give all the necessary information so that you have the best memory of that moment.
