Determine the exact length of pregnancy for ultrasound can only be if the survey was conducted in eight to twelve weeks. On a repeat visit to the doctor, the pregnancy period will be visible, but with each subsequent week according to the US, it will be increasingly difficult to determine the date of birth with high accuracy. This is due to the fact that inside the womb the babies develop differently and each kid has certain characteristics in growth and development.
Calculation of gestational age by ultrasound
If a woman has not undergone ultrasound examination for up to twenty weeks, a mismatch of the pregnancy period by ultrasound may severely upset her. Simply in such cases, doctors often diagnose an intrauterine delay in the development of the fetus , although there is none. But what she hears can traumatize a woman's psyche, and for the rest of her pregnancy she will only think about the pathologies of her future baby.
Such a verdict the doctor can make because of the fact that:
- at the beginning of pregnancy the period was not calculated correctly, because it was not determined by ultrasound;
- The fruit itself is of small size, perhaps as a result of heredity;
- a pregnant woman of a fragile constitution, and her fetus, respectively, will also be small in size.
There is a special table for the development of the baby, according to which the doctors set the exact terms of pregnancy, resorting to ultrasound:
After the ultrasound, where the formation and development of the fetus is clearly visible, the date of birth can be determined with the utmost precision.
Of course, the ultrasound period of pregnancy can be learned without problems. BUT! Due to the fact that there may be some differences and errors, it is better to determine the date of birth using other methods. These include:
- Last menstruation . In this case, the day of conception is considered to be the first day of menstruation.
- Examination at the gynecologist . Upon examination, the doctor can determine the duration of pregnancy, starting with 3-4 weeks.
- Determination of the deadline for the first "knock" . Women notice the stirring of the baby at the 20th week of pregnancy during the first pregnancy,
and those who have this second child - on the eighteenth.
Due to untimely visits to the clinic, pregnancy terms by ultrasound and those that are established using other methods will be different. Therefore, you need to be prepared for the fact that if the birth in the fortieth week is set on the same date, then the child may be born a little earlier or later. Deviations within the norm are considered plus-minus two weeks of the appointed date. After all, it is very difficult to calculate the exact duration of pregnancy . Unless the woman herself calculated the day of ovulation, and it was on that day that a conception occurred.