Weeks of amenorrhea: how to calculate, how many months?

Weeks of amenorrhea how to calculate how many months

The weeks of amenorrhea (or SA) make it possible to precisely date the pregnancy, but also to monitor the development of the fetus. How many weeks of pregnancy and months correspond to the weeks of amenorrhea? The point with Dr Sylvain Mimoun, gynecologist.

From the beginning of the pregnancy, your gynecologist will talk to you in weeks of amenorrhea (or in weeks of pregnancy) in order to define the date of the beginning of pregnancy, and to follow the development of the embryo then of the fetus and the progress of the pregnancy until its term. To know what week of pregnancy you are in, there is therefore two methods of calculation: the week of amenorrhea (SA) and the week of pregnancy (SG). To better navigate, there are two additional weeks of pregnancy compared to the week of amenorrhea (1 week of pregnancy corresponds for example to 2 weeks of amenorrhea or 3 SA).

What is the amenorrhea week?

There week of amenorrhea starts at first day of last period. Amenorrhea is the absence of periods or periods. It is one of the main signs of early pregnancy. Amenorrhea is then called “gravid”, that is to say relating to pregnancy. This symptom manifests itself on the first day of a menstrual cycle. From this day, we can then calculate the duration of the pregnancy. As for the week of pregnancy, it begins on the supposed date of fertilization.

Why talk about amenorrhea weekdays?

“While the calculation of weeks of pregnancy is based on averagesthat of weeks of amenorrhea is done from a date, which makes the calculation more precise”, explains gynecologist Sylvain Mimoun. This is why we talk more about amenorrhea weekdays, because this method allows doctors to Precisely date the pregnancy and thus better identify yourself on the medical pregnancy monitoring calendar. It is the most commonly used by practitioners. “I’ultrasound of pregnancy is also involved in the calculation of the duration of pregnancy. Because it makes it possible to confirm what has been estimated theoretically by counting the amenorrhea weeks“, adds the gynecologist.

“The calculation of the weeks of amenorrhea is done from a date, which makes the result more precise”.

How to calculate your weeks of amenorrhea?

To calculate his weeks of amenorrhea, it is necessary to start from the first day of the last period and add two more weeks to the weeks of pregnancy. Example: the end of the 1st month of pregnancy corresponds to 4 weeks of pregnancy (SG), i.e. 6 weeks of amenorrhea (SA). With this calculation, you will then know exactly how many weeks pregnant you are. Namely that the dating in weeks of amenorrhea can be subject to modification, especially in women with irregular cycles. The dating ultrasound will provide more precision.

What is the term of a pregnancy in amenorrhea week?

In France, the term of a pregnancy occurs at 41 weeks amenorrhea, i.e. 39 weeks of pregnancy. If baby shows the tip of his nose on this date, then we speak of a full-term baby.

How to calculate the weeks of pregnancy?

The calculation of the weeks of pregnancy takes as its starting point the theoretical day of fertilization. This occurs during sexual intercourse during ovulation period. “Basically, it occurs 14 days after the start of the period, but that’s an average”, says Dr. Sylvain Mimoun. But the calculation is not easy to establish precisely, because the fertile period extends from 1 to 5 days (ovulation period). During the first pregnancy ultrasound, the doctor can take several measurements of the fetus to precisely confirm the date of fertilization and therefore the start of pregnancy.

What does the weeks of amenorrhea correspond to during the months of pregnancy?

From the first day of fertilization, a “normal” pregnancy generally lasts 9 months, i.e. 39 weeks pregnant (270 to 280 days). Concretely, 39 weeks of pregnancy corresponds to 41 weeks of amenorrhea. Here is a table of correspondence month by month between the weeks of pregnancy and the weeks of amenorrhea:

Table to calculate weeks of pregnancy in weeks of amenorrhea © Women’s Journal

What is non-gravid amenorrhea?

Some amenorrhea are called “non-gravid” that is, they are not due to pregnancy. Amenorrhea is notably triggered at menopause. “There are also psychogenic period absences, due to trauma, which can last for a very long time”adds Dr. Sylvain Mimoun. “A woman who finds herself in this situation without knowing if she is pregnant should go see her gynecologist to determine the cause of her missed period”he advises.

Thanks to Dr Sylvain Mimoun, gynecologist and andrologist.

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