How can I find out the length of pregnancy after the last month?

Quite often, even before visiting a doctor, women who are in a position have a question about how to find out the length of pregnancy at the last monthly period. Let's answer it and we will dwell in detail on all methods of setting the gestational age that exist to date.

How do doctors schedule their appointment?

As a rule, when you first visit a gynecologist during pregnancy, the first thing a specialist asks is the date of the last menstrual flow. Typically, these data are used as a starting point for calculating the duration of the current pregnancy. The duration of gestation established in this way was called "obstetric term". Most often a woman can not say exactly the day that the conception occurred. That's why they count from the first day of the last menstruation.

Also, during pregnancy, the so-called embryonic, or the true term of gestation, is established. It is calculated from the day of fertilization or ovulation with the help of ultrasound. In this case, the doctor compares the size of the embryo with the corresponding table and determines the duration of the pregnancy that has begun at the current time.

How to determine the length of pregnancy for the last month?

This kind of calculation a woman can do on her own. All that is necessary to know for this is the exact date of the first day of the last menstruation and the duration of the gestation period (pregnancy). Normally it is 40 weeks, or 280 days. Thus, to find out the expected date of delivery, you need to add to the date of the first for the last menstrual period of 40 weeks.

If we talk about how to calculate the current term of pregnancy for the last monthly period, then the calculation of the duration of gestation should also be carried out according to the latest excretions. How many days from that moment has passed - such is the term of the current pregnancy.

As a rule, with this kind of calculation, physicians resort to the so-called Negele formula. According to her, it is necessary to add 9 months and a week (7 days) to the date of the first day of the last discharge. You can also do it differently - take 3 months from this date and add 7 days. The received date will indicate the estimated day of childbirth.

How to set the deadline correctly?

Calculate such a parameter as the duration of pregnancy for the last monthly exactly, it is unlikely to succeed. The thing is that far few women can say that they have a regular menstrual cycle, i.e. Monthly starts on the same day in each month and the duration of the excretions is always the same. It is because of these nuances in calculating the duration of gestation for the last menstrual days you can get an inaccurate result.

That is why, in order to accurately determine the duration of pregnancy, you need:

• visit a gynecologist;
• to pass an ultrasound;
• to pass the analysis on level hCG.

It is also necessary to say that often in order to clarify, if the deadline is calculated correctly, they resort to calculations on the first perturbation. So, by the day of the first stirring, 20 weeks are added if the woman carries the first baby, and 22 weeks - if the pregnancy is not the first. However, this method only allows you to confirm the accuracy of calculating the gestation period in the ways indicated above, because The first stirring is observed, as a rule, in the middle of pregnancy.

Thus, as can be seen from the article, it is not difficult to calculate the duration of pregnancy by the date of the last monthly period. However, it should be borne in mind that this kind of calculation is approximate and requires clarification by performing an ultrasound, by which the duration of gestation can be calculated to within 1-2 days.