How do doctors determine the duration of pregnancy?
Before gynecologists calculate the number of weeks of pregnancy, they will learn about the date of the first day of the month. It is the starting point for setting the deadline in this way.
As you know, a normal pregnancy lasts 40 weeks. Thus, in order to calculate the term of the expected delivery, the first day of menstruation should be added 280 days (those same 40 weeks).
This method is not very informative, because It makes it possible to establish only the estimated date of birth, which may occur earlier than the established period. This is explained by the fact that pregnancy is possible only after ovulation, which usually occurs on the 14th day of the menstrual cycle. That is why, the difference between obstetric and real term is 2 weeks.
Which method allows you to accurately determine the duration of pregnancy?
Thus, knowing how the obstetrical weeks of pregnancy are considered , the woman will know that the period, obtained as a result of such calculation, differs from the real one by about 14 days.