The normal gestation period is 40 weeks from the date of the
last menstruation.
The estimated date of birth can be added practically 7 days
to the date of the last menstruation and can be calculated practically by going
back 3 months. Here, the estimated date of birth is the last date when birth
can occur. Most births do not wait until this date, they take place between
38-40 weeks. Sometimes, people who pass the day may pass this date for 1 week.
That is, the birth estimate often happens 1-2 weeks before the result
calculated by the date of birth.
Sample:
The estimated date of birth of someone whose last menstrual
date is April 10
10 + 7 = April 17
From April -> 3 months back January -> January 17.
Sample:
For someone whose last menstruation date is February 5:
5 + 7 = February 12
If you go back 3 months from February 12: the estimated date
of birth is November 12.
However, this method may cause errors especially in people
whose periods are irregular. In this case, the estimated birth date is
calculated using the ultrasound measurements.
