How does the volume of the fetal head vary by week?
The fetal head circumference, like other indicators, varies by weeks of pregnancy. At the time of the first ultrasound, at 12-13 weeks it is 95-96 mm. At the same time, throughout the entire period of bearing the fetus, his head grows at different rates, i.e. growth then slows down, then intensifies.
Thus, the greatest increase in this parameter of intrauterine development is observed in the 2nd trimester of pregnancy. At this time, in particular from 15 to 26 weeks, this parameter increases by 12-13 mm every week. Then the growth rate slows down. Approximately one month before the appearance of the baby, it increases by only 13-15 mm.
How is the fetal head circumference measured?
The measurement of this parameter in a child is carried out using an ultrasound machine. In this case, the study is carried out in several projections to obtain a more accurate result. As already mentioned, this parameter is included in the group of fetometric indicators, which also includes the length of the hip, abdominal circumference, length of the fetus and its weight.
How are the measurement results evaluated?
To assess the size of the fetal head circumference, a table was compiled, indicating the norm-the average values of this parameter, corresponding to a certain stage of intrauterine development.
The doctor evaluates the results of the measurement, taking into account other, equally important indicators of the development of the baby. At the same time, there is no strict binding to a certain parameter, because each organism is individual. But, despite this, there are so-called limits of norms, the excess of which can speak of the development of a violation.
What is the deviation of the size of the head circumference from the norm?
As is known, often any deviation from the norm of this or that indicator of the intrauterine development of the baby testifies to the presence of any violation. In such a situation, the main task of physicians is to identify and correct it earlier.
So, for example, a large head circumference in the fetus may be a symptom of a disease such as hydrocephalus. It lies in the accumulation of fluid in the intracranial cavity. In this case, the brain is underdeveloped, due to a decrease in its size. After the birth of the baby, puncture is almost immediately performed, in order to remove the accumulated fluid and reduce the intracranial pressure, which facilitates the state of the crumbs.
However, in most cases, the increase in the volume of the head is attributed to the individual characteristics of the development of the fetus. So, if the parents of the baby have high parameters of physical development, it is most likely that the baby will be large.
In cases where the future child has a large head circumference, the generic process has its own characteristics.
Thus, it can be said that the head circumference is not only an important parameter of fetal development, but also a characteristic that can not be ignored in the delivery. After all, if during the ultrasound it was found that a woman has a large fetus, then if there are indications, a planned cesarean section can be prescribed. This is done to prevent the development of complications.