The most common way to calculate the date of birth application date the first day of the last menstrual period. To this day add 280 days (10 obstetric months, or 9 calendar months of pregnancy), received date is the date of birth.
Another easy way to calculate the date of birth from the date of the first day of your last period count back three calendar months and add 7 days.
To determine the date of childbirth can be, and the date of the first fetal movements. This method of calculation is only possible if the future mother will be very watchful and attentive to their feelings and remember (and most importantly, you will understand that it is perturbation) the date of the first fetal movements. To this date in the first pregnancy add 20 weeks, and in the second and subsequent 22 weeks, and get the approximate date of childbirth.
Gynecologist can calculate the duration of pregnancy and date of delivery and directly through visual inspection, but only on condition that the woman went to the doctor before 12 weeks of pregnancy.
To reliably calculate the date of birth by using ultrasound. It is important that the first study was conducted in the early stages of pregnancy up to 12 weeks. Ultrasonography conducted at the later stages of pregnancy, gives less reliable information about the date of birth, as this method of determining pregnancy based on the measurement of the size of the fetus, and the growth and development of the fetus during pregnancy is strictly individual.
To calculate the estimated date of childbirth possible, using the date of care tothe birthOh a vacation. It is calculated by the 30th week of pregnancy. Means to determine the date of birth should be added to the start date of decree 10 weeks.