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.
Advice 2: How to determine the duration of pregnancy and date of birth
In some cases the woman may not exactly understand what her period of pregnancy and when childbirth. To calculate these dates, there are special techniques that can be used by both physicians and pregnant women themselves at home.
Contact your gynecologist. He will be able to make an accurate calculation, based on the date of your last menstrual period and the size of the child identified on ultrasound. Also the doctor takes into account the size of the uterus. Uterus length of 12 cm approximately corresponds to the third month of pregnancy.
Pass the analysis to the hormone HCG. It appears in a woman's body during implantation of the embryo and the amount of the hormone increases daily. It is determined by the level of HCG pregnancy while using home tests, as it is detected in the urine. This analysis is especially useful in the early period, up to 6-8 weeks of pregnancy. For the first weeks after conception the normal HCG - 150 mu/ml, and at the eighth week, approximately 70,000 IU/ml. keep in Mind that the deviation in performance may indicate non-standard situation about pregnancy. Insufficient levels of HCG and its slow growth may indicate a risk of miscarriage or ectopic pregnancy, and significantly higher than the norm - a pregnancy with twins or triplets.
Make the counting of time alone. To do this, specify the date of their last period. From them and calculated the duration of pregnancy in weeks. It turns out the so-called obstetric period, which may differ from the date of conception. Normal births occur on the fortieth to forty-second week of obstetric period, that is from the last menstruation. However, in some cases they may occur earlier or be delayed due to overdue pregnancy. The exact date of the onset of labour will not be able to predict even the doctor.
Define the term size belly and the wiggling child. The stomach becomes visible usually in the fourth month, and to move noticeably to the mother the child starts at 18-20 weeks. If a woman is pregnant not for the first time, it is likely that she will feel movement earlier.