Modern medicine has made tremendous progress inquestions of examination of pregnant women, and if earlier it was considered quite sufficient to undergo ultrasound examination of the fetus and to pass some tests, then these days this category of patients is under the watchful eye of specialists and subjected to periodic procedures and examinations. Basically, they are aimed at determining the state of the developing in the womb of the mother's baby and timely diagnosis of various anomalies. Including - ultrasound detection of such characteristics as the norm of the nasal bone, conducted after ten weeks of pregnancy.
Pair of quadrangular form of nasal boneis determined during visualization during ultrasound at 12 weeks of gestation. Its absence at this time or a deviation from the generally accepted standards later indicates an incorrect intrauterine development of the child, moreover, it can signal the presence of Down's syndrome in the baby. In such situations, it is recommended to conduct an additional examination.
Some experts, knowing the norms of the firstscreening, use comparative tabulated values, comparing their values with the results of ultrasound. And again, we should not forget that the very fact of the presence of the fetal nasal bones is of prime importance during the 10-12 weeks of pregnancy, and the measurements are not so significant, because the chromosomal abnormalities of ossification occur later.
Отдельные периоды развития и роста плода are characterized by certain regularities. One of the main parameters is the length of the nasal bone. The norm of the nasal bone at 12 weeks is about three millimeters in length. Later, by the 21st week, this value reaches 5-5.7 millimeters, and by the 35th week - 9 millimeters.
Accuracy of measurement of ultrasound of the embryo depends not only on the perfection of the equipment, but also on the experience and professionalism of the specialist.
The norm of the nasal bone in 12 weeks of fetal development,as well as in the subsequent months of a woman's pregnancy, is systematized and serves as a starting point in the study of ultrasound results. Based on the information received, doctors monitor the entire course of the intrauterine stay of the baby and identify the presence or absence of anomalies.
If the nose bone is not visualized, butthe collar part is thickened, then the probability of birth of an infant with Down syndrome or congenital defects of the face is extremely high. Knowing this, many parents prefer abortion. Since the birth of a healthy child is a task not only for mothers, but also for doctors, such a significant indicator is assigned to such an indicator as the norm of the nasal bone in 12 weeks. The table below gives a graphic description of its increase during the course of pregnancy.
Term, weeks | The minimum value, mm | Maximum value, mm |
| 12-13 | 2,0 | 4,2 |
| 14-15 | 2,9 | 4,7 |
| 20-21 | 5,7 | 8,3 |
| 22-23 | 6,0 | 9,2 |
| 32-33 | 8,9 | 13,9 |
| 34-35 | 9,0 | 15,6 |
After the tenth week of gestationyou can make measurements of the most important characteristics of the fetus. The norm of the nasal bone in 12 weeks should correspond to the required parameters, otherwise we will have to think about the possible severe chromosomal problems of the unborn child. Hypoplasia is considered a symptom of such complex diseases as Down syndrome, Edwards syndrome, Patau, Turner syndrome, etc.
To obtain a more accurate result, appointexpert ultrasound examination of the fetus, and with the repeated confirmation that the norm of the nasal bone does not correspond to the necessary values, genetic analysis of the amniotic fluid is carried out. This will allow an objective assessment of the in utero state of the baby, as it is in this environment that oxygen, carbon dioxide, hormones, fetal metabolism products, enzymes accumulate.
Making sure of the results of ultrasoundDiagnosis is that the parameters of the nasal bone of a future child are less than normal, the parents succumb to endless despair. It is not worth reacting that way, because one of these parameters is not enough to diagnose Down's syndrome or other serious pathological condition. And although the norms of the first screening are to some extent indicative, one should calmly wait for the repeated results of a deeper examination.
Still need to understand that every child in the periodfetal development is individual, therefore the sizes of separate parts of a body will differ, including a nasal bone in 12 weeks. But if the study of the fetus demonstrates obvious defects of internal organs and shortening of the limbs, then in these cases it is possible to speak with confidence about congenital malformations.
Perinatal screening is a uniqueexamination of the future mother for the detection of the danger of congenital and acquired pathological conditions of fetal development, the results of which are compared with the averaged values.
In the first trimester of pregnancy (10-12 weeks)perinatal screening makes it possible to recognize early enough abnormalities in the number of chromosomes, a defect in the anterior abdominal wall and pathology of the neural tube, as well as various threats to normal childbearing in general.
Based on the rates of RAPP and hCG,characterizing the pregnancy, as well as the value of the thickness of the collar space in the embryo, judge the risk of possible defects. If the norms of the first screening do not coincide with those of the analyzes performed, the pregnant woman is assigned a study of the genetics of the unborn child and a biopsy of the villus of the chorion.
The rate of nasal bone at 12 weeks duringultrasound study allows to make a conclusion about a good, healthy development of the fetus in early pregnancy. If its length deviates from the accepted standard in the direction of reduction, then hypoplasia of the nasal bone is present. But there are exceptional cases when a number of surveys conducted do not reveal it at all. Then the question is raised about aplasia of the nasal bone, in other words, the complete absence of an organ.
На самом деле причин патологических отклонений от There are many normal indicators of the length of the paired bone of the nose of the fetus, and all of them are of a different nature. This may be, for example, chronic alcoholism of one of the parents or the serious consequences of smoking. Women who have had flu, colds and other diseases in the first trimester of pregnancy are automatically at risk.
There are also other reasons that the rate of the nasal bone in 12 weeks of fetal development does not get, namely:
Thus, in addition to chromosomal abnormalities and socalled genetic predispositions, lifestyle and health of the expectant mother directly affect the intrauterine development of her fetus. And modern medicine, thanks to the newest methods of diagnosis, allows to detect and control chromosomal abnormalities in a baby at a sufficiently early gestational age, the consequence of which can be Down syndrome. In any case, it is the attending physician who is able to determine the true diagnosis or eliminate the possible risks on the basis of the most accurate analyzes and studies.
