While tying herself to her, many future mothers choose their baby for their little ones, learns the character on different horoscopes. Therefore, it is so important for them to know it by themselves before determining the preliminary date of birth. But knowing the period of conception does not mean accurately determining the term of childbirth. And not all future mothers plan their pregnancy.
The preliminary date of delivery is necessary for orientation during pregnancy. And for that it is preliminary, in order to be guided by it approximately. Usually, women give birth to a week, or even two. A fateful event can take place in 42 weeks, that is, 38-42 weeks of the term is considered a physiological pregnancy. And before and after, there are some risks.
Today there are several actual methods for calculating PDRs. The first is focused on the beginning of the last menstruation, that is, its first day.
This term is called obstetrical and usually is longer than the actual period of bearing the baby. Calculation of the date of birth in this way is done in several ways:
- According to the formula of Nehiel. From the first day of the last menstruation, three months are taken away, then 7 days are added.
- Add to the start date of the monthly 280 days (exactly 40 weeks).
The accuracy of such calculations by practice is subject to correction and wishes the best. And women with an irregular cycle, they do not fit. When the cycle is less than 28 days, then in the above formula you need to make significant adjustments. But since women are more likely to know the date of the onset of their monthly than the date of conception, then doctors are guided by such a calculation of PDR.
By the date of ovulation, the preliminary date of delivery is much easier to calculate. But we emphasize that this method is acceptable for women who have had a stable cycle for the last year. By the date of ovulation, 268 days are added, that is, not 40 weeks, but 38.
The woman can obtain accurate information about the date of her ovulation by measuring the basal temperature. This is done in the morning, without getting out of bed, for a month. And the beginning of an important period of the menstrual cycle is determined by raising the temperature to 37.2 degrees, or maybe slightly more.
Also, sometimes PDR is determined by the date of arrival of the future mother in the women's consultation. Experienced gynecologist in 4 weeks of the term will determine the presence of pregnancy. And then the doctor is already guided by this date, adding to it 36 ??weeks. But the disadvantage of this method is that today future mothers do not visit early gynecologists, they prefer tests, and they register for up to 12 weeks as prescribed.
Another option for calculating the PDR is to focus on the first stirring of the baby, which usually occurs on the 20th week of his gestation. By the date the same number is added and the coveted landmark is established.
To date, the most accurate is the calculation of PDR by ultrasound. This medical manipulation allows you to estimate the size of the fetal egg and, accordingly, the duration of pregnancy. For a period of up to 12 weeks, a specialist can already determine the size of the body parts of a future boy or girl.
It is worth noting that today the PDR is determined taking into account several ways of its calculation. After all, they all give not too high accuracy. Statistics show that at the appointed time, only 5% of women become mothers. Others from the date are rejected for a week or ten days in one or the other direction. Proceeding from this, the woman should be ready before birth, in advance, and on the account to rise, as well as it is necessary, till 12 weeks. This is necessary for the early detection of factors and threats that hinder the bearing of the fetus.