Every future mother from the moment she learned about her pregnancy wants to know when her baby will be born.
How do I know the expected date of delivery?
The estimated date of delivery (PDR) is determined by the gynecologist at the first admission and then repeatedly specified. This date is the reference point by which a woman and her doctor prepare for the birth of a baby.
Calculate the expected date of birth, the future mother can and independently, using special calculators, which based on the date of the last monthly give an answer about the expected date of birth.
You can set the expected date of birth according to the table below. For this, it is necessary to find the date of the beginning of the last critical days in the blue line; the expected day of birth is the date under it in the white line.
The calculation of the expected date of birth in these cases is based on the use of the so-called Negele formula. From the first day of the cycle, three months are taken away and seven days are added. This calculation is rather approximate, since it is designed for women with a standard 28-day menstrual cycle. In the case of a longer or shorter cycle, labor can begin later or earlier, respectively.
The formula of Negele loses its relevance if the cycle of a woman is irregular. This formula for determining the expected date of birth is the basis for creating obstetric calendars, with the term of birth in this case called obstetric.
Determination of the expected date of delivery
Naturally, this is not the only way to establish an approximate date of birth of the baby.
For these purposes, a lot of methods are used, the most accurate result of which is the definition of the expected date of delivery based on the results of ultrasound carried out in the first trimester of pregnancy . It is at the beginning of pregnancy that all babies develop the same way, so there are no significant differences between the sizes of embryos. Applied later this method does not give a reliable result due to the individual developmental features of each baby.
The gestation period and, accordingly, the possible date of birth are set according to the size of the fetus to the accuracy of the day. In addition, to calculate the expected date of birth, the doctor helps to conduct an examination of a pregnant woman, during which the height of the uterine fundus and its size, the size of the fetus, the volume of the stomach is determined. The accuracy of determining the duration of pregnancy depends on how early a woman turns to a gynecologist.
To calculate the expected date of birth, you can also use the method of calculation for ovulation. To do this, a woman should accurately navigate in her menstrual cycle - to know its duration and the date when ovulation occurred, because conception could occur only after the moment of ovulation. If a woman does not exactly control her cycle and does not know when the ovulation occurred, then it must be assumed that the female cycle lasts from 26 to 35 days, with the ovulation date being in the middle of the cycle. Therefore, to know when this happened, you can simply divide the entire cycle in half. If the cycle consists of 28 days, the egg ripens on days 12 to 14. To this date, you need to add 10 lunar months (for 28 days each) and get the date of the expected delivery.
To determine the expected date of delivery, the woman is also invited to pay attention to when she feels the first movements of the fetus . As a rule, the future mother begins to feel for her baby on the 18-20th week.
Every pregnant woman should clearly understand that it is impossible to know exactly the date of birth of her baby in advance, at least because the intrauterine period of development for each child is different and amounts to 37 to 42 weeks. Therefore, only the estimated date of delivery is to be guided.