When you get pregnant right away you start doing accounts to know when your baby will be born, what will be the appointed day. While the percentage of babies born on the day that marks the calendar is very low, only 5 percent, know the probable date of delivery It will help you to have an orientation date.
Since pregnancy is counted for weeks, there are those who believe that instead of a specific day it would make more sense to talk about a probable week of delivery. If you want to know when you will leave accounts we will show you how the probable due date is calculated.
Duration of pregnancy
The approximate duration of a pregnancy is 280 days. Is calculated 40 weeks from the first day of the last menstruation (FUR) or 38 weeks (approximately nine months) from the moment the fertilization of the ovule occurs, which in a regular period ovulation usually occurs 14 days after the menstruation occurs.
As not all women know the time of ovulation and because it is impossible to know exactly the date on which the conception occurred, the date taken into account to calculate the probable date of delivery is the first day of the last menstruation.
Nagele Rule
You can make a simple calculation to know your probable due date (FPP): a formula known as Nagele Rule. Consists in subtract three months and add seven days to the first day of your last period. The result is the probable date of delivery.
For example, if your last period was January 1, you have to subtract three months, and add seven days: the probable date of delivery is October 8.
Calendar of probable delivery date
The gynecologist in his office usually uses a wheel calendar to calculate the probable date of delivery and a gesture to know the measures and the weight of the fetus during pregnancy, week by week.
Another format is in the form of a table, like the one we show you below with which you will be able to know your probable date of delivery (FPP).
How to interpret the table? You have to identify in bold line (the one that begins with January, February, etc.) on the first day of your last period and the month. The number that appears right on the line below is the probable delivery date of the month indicated on that same line.
Probable (or unlikely) date of delivery?
As we said before, very few babies are born on the day of the probable date of delivery. So much so that there are those who believe it should be called "unlikely date of delivery." On the one hand, having a precise date can help you in an orientative way, but on the other hand it can be very anxious to know what the day is about or what has happened and the delivery is not triggered.
It must be taken into account that it is considered a term delivery that occurs between weeks 38 and 42 of pregnancy, two weeks before and two after the date of delivery. It's no less than four weeks, 28 days when the baby could be born. Hence it is more successful to talk about probable week of delivery.
In any case, the precise calculation of gestational age will be determined by the gynecologist after performing the first ultrasound and taking the measurements of the fetus, which can be in the first weeks of pregnancy or on the ultrasound of week 12.
In the first weeks, the fetus grows by exact millimeters and thus it can be verified if the probable date of delivery calculated with the Nagele Rule coincides with the measurements taken on the ultrasound, or else recalculate it according to the measures observed. For this reason, many times, gynecologists change the FPP after performing this first ultrasound.
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In Babies and more | What is the purpose of knowing the probable date of childbirth (FPP) ?, Calendar to know the probable date of childbirth (FPP)
