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The reason for the expansion of the twins of the fetus is 12 weeks. TVP on ultrasound: definition and assessment. Possible deviations from the norm

The thickness of the collar space is one of the most mysterious indicators of ultrasound during pregnancy for expectant mothers, and even normal numbers are alarming due to ignorance of how it should be and rumors that this indicator, or rather its deviation, is evidence that a patient will be born child.

What is collar space?

In order to correctly assess the collar space, ultrasound is performed at 11-14 weeks of pregnancy. At this time, the child has a fold of skin behind the neck, which is an accumulation of fluid in the subcutaneous tissue. Later, the liquid dissolves (norm 2-3 mm).

If you have a normal pregnancy, the collar space begins to decrease at 13-14 weeks, and is no longer detected in the second trimester.

The thickness of the fetal collar space should not exceed 3 mm, if it is wider, this indicates an increased risk of chromosomal abnormalities.

In about a third of cases, when the collar space is more than 3 mm wide, the baby is subsequently diagnosed with Down syndrome (50%), or other chromosomal syndromes.

The size of the collar space is assessed during 1 screening ultrasound, most often at 11-12 weeks. The wider the collar space, the higher the risk of chromosomal abnormalities in the child. Doctors have long determined the degree of risk for a child, depending on the severity of the deviation from the norm, a special table of the collar space has been created, which characterizes this risk in% with different degrees of its increase.

Various indicators are determined that reflect the state of the child, the degree of normality of his development. Among them, particular importance is attached to the indicator of the thickness of the collar space of the fetus (TVP), otherwise it is called the cervical fold. This parameter must be definitely determined by ultrasound during pregnancy. Evaluating this indicator, it is possible to diagnose genetic chromosomal abnormalities and fetal malformations with a fairly high accuracy.

TVP is determined by ultrasound examination in the 1st trimester

The assessment of this important indicator is included in the 1st screening study, which is carried out at the end of the 1st trimester - at 12 weeks. Ultrasound examination of pregnancy at 12 weeks is performed in order to detect chromosomal abnormalities in the fetus. This is done by measuring some important metrics. It is at 12 weeks that ultrasound can reveal the possibility of chromosomal abnormalities in a child.

What is TVP?

The collar space is the fold of skin behind the neck where fluid collects. It is believed that a small amount of fluid in the cervical region is typical for all children in fetal development. The size of this fold is measured for diagnostic purposes, it is not the very fact of the presence of fluid in the subcutaneous space of the neck that is important, its quantity matters.

By measuring TVP, the degree of risk of having a baby with Down syndrome and other abnormalities is determined. Scientists have found that the liquid in this zone, or rather its accumulation in large quantities, may indicate the presence of genetic abnormalities in the fetus.

So, in children with Down syndrome, the fluid in the collar space significantly exceeds the existing norms. In addition, with Down syndrome, there is an increased folding of the skin; this condition is also characterized by the accumulation of fluid in this area. The accuracy of such a diagnosis can only be confirmed after additional research.

It is necessary to understand that with the help of this indicator, not the disease itself is detected, but only the degree of probability of its occurrence in a child is determined. If deviations from the norm of this indicator are detected, a pregnant woman can be referred for a consultation with a geneticist, who, based on the results of all studies, will determine the degree of risk and, if necessary, recommend a chorionic biopsy.

How is the TVP indicator determined?

The measurement of TVP is carried out by the ultrasound method, which is carried out by a transvaginal or transabdominal method. The optimal time for ultrasound measurement of this indicator is 12 weeks of pregnancy.

The need to comply with such terms is due to the fact that earlier or later than these terms, a study to determine TVP will not have diagnostic value, since the data obtained as a result of the study will be unreliable. The difficulty in determining TBP before 12 weeks is associated with the small size of the child. A later measurement of this fold is undesirable, the data will not be informative. Since the fluid accumulated in the collar area after 12 weeks can be absorbed by the fetal lymphatic system, which at this time begins to actively develop.

Before measuring this indicator, the doctor must accurately determine the gestational age. To determine the term is measured (coccygeal-parietal size). Correct measurement of TVP assumes that three conditions are met:

  • conducting an ultrasound scan at 12 weeks of pregnancy;
  • strict adherence to the sagittal plane along which scanning will be performed;
  • CTE should be 45 - 84 mm.

The results of the study can be influenced by various factors that can distort the obtained data. Such factors may include:

  • the professionalism of the ultrasound diagnostic doctor who will conduct the study;
  • the state of the equipment with which the research is carried out;
  • clarity and size of the image on the monitor of the device;
  • untimely ultrasound;
  • if the measurement is carried out not along the outer, but along the inner contour of the cervical fold;
  • the position of the fetal head during ultrasound.

The position of the fetus during the ultrasound scan can affect the results of measuring the thickness of the collar zone. So, extension of the head by a child can increase this indicator by 0.6 mm. If, during an ultrasound scan, the baby pressed his chin to his chest, then there may be a decrease in this indicator by about 0.4 mm. Therefore, the measurement data can only be reliable when the indicator is measured in the correct position of the fetus. Thus, the measurement of the collar fold parameter cannot give unambiguous answers as to whether there is a pathology or not.

What values ​​of TVP are considered normal?

The thickness of the collar area should normally be no more than 2.7 mm.

Thus, the rate of TVP indicators fluctuates within the following limits:

  • from 10 to 11 weeks - up to 2.2 mm;
  • 12 weeks - up to 2.5 mm;
  • 13 weeks - up to 2.7 mm.

The deviation of the indicators towards a decrease is not regarded as a possible sign of pathology. If there is a deviation of the indicators in the direction of increase, then this indicates the possible presence of chromosomal abnormalities.

The likelihood of the risk of chromosomal diseases increases with the increase in the size of the collar fold.

The age of a pregnant woman can also increase the risks: the older she is, the higher the risk of developing abnormalities in the child.

In case of thickening, it is also necessary to pay attention to the size of the nasal bone, since with chromosomal abnormalities, the parameters of the nasal bone in the fetus do not correspond to the gestational age, they are several times less than the norm. In addition, if chromosomal diseases are suspected, a short upper jaw is noted, which leads to a smoothing of the facial contour. This is also an additional diagnostic sign of this kind of deviation.

Decoding of the results is carried out using a special program. To determine the risk, data on the woman's age and indicators of the size of the collar fold are entered, as a result, the degree of probability of risk is determined.

Practice shows that such a thickening of the cervical fold is not a guarantee of the birth of a child with developmental anomalies. In such cases, healthy babies are often born, despite the fact that a certain risk has been identified. Nevertheless, the TVP indicator is very reliable, since, according to statistics, in 75% of children with Down syndrome, pathology was detected when measuring the thickness of the collar zone. The advantage of this method is that it is performed early in pregnancy. This allows for a timely chorionic biopsy to clarify the diagnosis.

Thus, the measurement of the index of the collar zone in the 1st trimester is one of the primary tasks of ultrasound of pregnancy. Timely diagnosis of chromosomal pathologies will make it possible to make a decision about the prospects for the development of pregnancy.

What pathologies does TVP detect?

A study of the thickness of the collar fold at 12 weeks is designed to identify abnormalities in the intrauterine development of the fetus. These deviations concern such chromosomal pathologies as Down, Edwards, Turner, Patau syndromes.

These pathologies are caused by trisomy - the presence of an extra chromosome (Down, Edwards, Patau syndromes) and monosomy - the absence of one chromosome (Turner syndrome).

Down syndrome is characterized by the presence of trisomy - instead of 46, the child has 47 chromosomes. Edwards syndrome is a chromosomal pathology that combines a whole range of developmental defects (heart, kidney, brain, etc.). This disease is characterized by a deep degree of mental retardation, pronounced external defects. The cause of this disease in trisomy 18 of chromosome is the presence of an extra copy of the chromosome.

The likelihood of such chromosomal diseases is directly related to the increase in the size of the TVP. If the indicators at 12 weeks differ from the norm, the woman is included in the risk group and she is assigned a comprehensive examination. It includes ultrasound, blood test for beta-hCG and PPAP-A, age screening and prenatal karyotyping. After such a complete examination, a conclusion is given with a note on the degree of risk for chromosome abnormalities.

If, as a result of the examination, a high risk is determined, an amniocentesis procedure is recommended for a pregnant woman. Its essence lies in the collection of amniotic fluid in order to determine the chromosome set in the fetus. The chromosome set can also be determined using a method such as cordocentesis. In this case, blood is taken from the umbilical cord for analysis. It should be noted that all these procedures are carried out only with the consent of the pregnant woman, that is, on a voluntary basis. All the information regarding such manipulations is conveyed to her, and she has the right to choose whether to undergo such an examination or not.

When pathologies that are not associated with chromosomal abnormalities are detected, pregnancy should proceed within the normal range. If serious defects are revealed that are not compatible with life, the woman is recommended to have an artificial termination of pregnancy. If Down syndrome has been identified, then the family has the right to independently decide on the continuation of the pregnancy.

During the stay of the baby in the womb, the woman undergoes numerous examinations and tests. Such diagnostics are necessary in order to know the state of health of the expectant mother and her baby. An obligatory examination during pregnancy is an ultrasound scan. It is this diagnosis that makes it possible to identify possible deviations and disturbances in the development of the embryo. In this article, we will talk about what is the norm for the thickness of the collar space at 13 weeks. You will learn how the examination of this education is carried out. Also get acquainted with the possible problems that arise if the baby's collar space does not fit into the permissible values. It is worth saying a few words about what to do in case of a deviation from the norm.

What is the collar region of the fetus

To begin with, it is worth saying what the collar space is. This is the place where fluid collects between the baby's neck and the baby's upper skin. This formation most often has an oblong shape.

It is displayed in black on the monitor of the ultrasound machine. Whereas the skin is white. The width is measured at the widest point of the given formation.

The norm for the thickness of the collar space at 13 weeks: how the examination is carried out

At this time, the expectant mother is examined using a transabdominal sensor. In some cases, when it is difficult to establish what is needed, the transvaginal method can also be used.

The woman sits on a flat couch on her back. Before starting the diagnosis, a specialist must use a conductive gel. It facilitates the movement of the transducer and improves sound conductivity.

The position of the fetus during the diagnosis should be lateral. Only in this state can a specialist see an accurate cut and measure the cervical spine.

How the collar space (norm) depends on the duration of pregnancy

The measurement of this object should be made between 11 and 14 weeks of baby's development. This limitation is due to the following. At 10 weeks, the size of the fetus is still very small and some specialists fail to grasp the desired position of the crumbs. After that, a gradual decrease (resorption) of this fluid accumulation begins. In this regard, diagnostics at this time may be uninformative.

The collar space (norm) increases in size from 10 to After this period, it begins to gradually decrease, practically disappearing by the 16th week of embryo development.

The norm of the width of the cervical region of the fetus

There is a set (norm) for everyone. See this article for a table of valid values.

If the expectant mother undergoes ultrasound diagnostics at 11 weeks of development of the baby, then for this fetus the permissible values ​​of the width of the formation are in the range from 0.8 to 2.2 millimeters.

In the case when the diagnosis is carried out at a period of 12 weeks of pregnancy, the norm of the collar zone has boundaries similar to the previous period. So, the range of values ​​is from 0.8 to 2.2 millimeters. But it is worth noting that the same fetus cannot have the same data at different weeks of pregnancy.

The norm for the thickness of the collar space for 13 weeks is as follows: from 0.7 to 2.5 millimeters. A few days later, the distance may already reach 2.7 millimeters, which is also a normal indicator.

In addition to the permissible width, the specialist also marks the minimum boundaries. The norm for the thickness of the collar space at 13 weeks or earlier should not be less than 0.3 millimeters. Otherwise, we can talk about the thinning of this zone.

Also, when measuring, it is worth considering the position of the fetus. The embryo's head should lie horizontally and flush with the body. If the future baby bends the neck and presses the chin to the chest, then the width of the collar zone may be underestimated. It also happens in the opposite case. If the crumb tilts the head back, then this segment expands. These conditions must be taken into account when taking measurements.

Deviations from normal values

If it is diagnosed that the collar space does not fit into the range of acceptable values ​​at 13 weeks (the norm has not been identified), what should be the next steps in this case? Most often, this result indicates a possible chromosomal abnormality. So, the thinning or expansion of the collar space in the fetus indicates the presence of Down syndrome.

In this case, the specialist issues an ultrasound examination protocol with a conclusion that speaks of the possibility of pathology. Most often, the doctor prescribes an additional examination, which is carried out after one or two weeks (if time permits). Also, the expectant mother is recommended to take a blood test to determine the risks. It is this kind of diagnostics, in combination with ultrasound examination, that makes it possible to establish the presence of chromosomal pathology as accurately as possible.

What to do if an anomaly is detected

If an additional examination showed the presence of Down's syndrome or another, then the woman is offered to conduct a number of additional studies. Most often, the diagnosis consists in taking material from the umbilical cord or fetal bladder. After the examination, a reliable conclusion is made. If congenital defects are confirmed, the woman may decide to terminate the pregnancy.

Does everyone have the same rate at 13 weeks of pregnancy?

It should be noted that you cannot rely on the data of your friends or relatives. If in one fetus the thickness of the collar zone was, for example, 1.3 millimeters, and in the other 2.0 millimeters, then this is a normal value. Do not sound the alarm and say that the second child has risks. The data fit into the allowable values ​​and this is the most important thing.

Often the normal values ​​can be somewhat blurred. On different devices and on different days, the width of this formation may differ by several millimeters. This is not critical.

Every pregnancy is different. What happened the first time can be radically different from everything that happened in the second.

Summing up and conclusion

Be sure to complete all studies prescribed by your doctor. Only in this case you will be sure of the health and normal development of your unborn child. Never give up the first one. After all, it is this diagnosis that allows you to identify possible deviations in

The width of the cervical spine is an important indicator. Now you know what is the norm for the thickness of the collar space at 13 weeks of pregnancy and at an earlier (later) time. Try to get ultrasound diagnostics from the same specialist. In this case, the data will be as reliable as possible. Easy pregnancy for you and good results in the thickness of the collar space of the fetus!

Every woman, having learned about her pregnancy, thinks only of good things and looks forward to the birth of a long-awaited baby. But the first ultrasound comes, and sometimes it turns out that some parameters of the fetus are outside the normal range. And one of these important markers is the thickness of the collar space. How is TVP measured correctly? What do doctors do if this indicator is increased?

What is the indicator - TVP

The abbreviation TVP in medicine stands for "the thickness of the collar space".

Any fetus on the back of the neck has an elongated area enclosed between the skin and muscles with ligaments. Until a certain period in the first trimester, it is filled with liquid - this is TVP.
During the first trimester, the fold between the skin and muscles in the fetus is filled with fluid.

Starting from the 10th gestational week, this parameter in the unborn child has its own specific values ​​(until this time, the fetus is too small to evaluate this marker). An excess of TVP in comparison with the standard indicators may indicate certain deviations in the development of the baby (including very serious ones).

From 10 to 14 weeks, the value of TVP in a particular child consistently increases - by 1–2 mm weekly. After 14 weeks, the liquid in the space of the "collar" begins to dissolve gradually and subsequently disappears altogether, so that it becomes more difficult to detect the pathology.

In some rare cases, the fluid transforms into neck edema or hygroma.

For how long and how is the ultrasound done

TVP is fixed using a routine ultrasound scan for a period of 11 to 14 weeks (for many expectant mothers, it becomes the first in this pregnancy). As a rule, the study is abdominal, but sometimes a transvaginal one is required if the fetus is poorly visible.

Absolutely all pregnant women are sent to such an ultrasound scan, even without any special indications.


 The doctor evaluates the TVP during an ultrasound examination

Before evaluating TVP, the doctor must measure the CTE of the fetus, or its length. This allows you to clarify the duration of pregnancy, because in the early stages, the sizes of all babies are still almost the same. Then the ultrasound doctor displays the upper part of the body (head and upper chest) in a strictly lateral projection on a computer monitor and enlarges the cervical region using scaling. After that, the maximum thickness of the accumulation of fluid under the skin surface is measured. On the screen of the ultrasound machine, it is displayed in a dark color (while the tissue of the fetus itself is white). After receiving the result, the doctor compares it with the established norms.
To measure TVP, the uzist displays the upper body of the fetus in a lateral projection and brings the neck area closer.

The back of the nose, the bone of the upper jaw, and the cavity of the 4th cardiac ventricle should also be in the lateral projection. After all, for example, anomalies in the structure of the nasal bone can also indicate abnormalities in the development of the fetus.

Factors contributing to the quality of measurements

In order for the definition of TVP on ultrasound to be as reliable as possible, certain rules must be followed:

  1. The fetal head should be neutral, level with the body. After all, if it is too thrown back, then the value may be overestimated (up to 0.4 mm). If the chin is too close to the chest, then, on the contrary, it is too low. In addition, the baby should not be pressed against the uterus. Therefore, it is likely that the doctor will have to wait until the baby is properly positioned. Or the doctor can press lightly on the mother's stomach, suggest that she cough. Meanwhile, many ultrasound examinations are carried out "on stream", especially free ones, when two dozen pregnant women sit in line, so this requirement is not always met, which leads to errors and, as a result, unnecessary worries in women.
  2. For measurement, you need to select the widest part of the cervical fold.
  3. It is necessary to undergo an ultrasound scan strictly within the recommended period, best of all at 12 weeks (if an increased TVP value is detected, it can be viewed again after 1-2 weeks).
  4. For the study, you should choose a highly qualified specialist, based on personal experience of a previous pregnancy, reviews of friends. It is better to do repeated ultrasounds with him (the information will be the most reliable).
  5. An important role is played by the quality of the equipment, as well as the size of the image: the recommended scale is 2/3 of the ultrasound picture.

Table: the rate of TVP according to the duration of pregnancy

Causes of increased TBP in the fetus

The increase in the amount of fluid in the fold of the neck of the fetus, and, consequently, the expansion of this zone, can be caused by many reasons. Some of them are associated with chromosomal abnormalities:

  1. Down Syndrome. The reason is one extra chromosome (47 instead of the required 46 due to three 23 chromosomes). It manifests itself in the form of an abnormal structure of the face, skeleton, underdevelopment of organs and psyche.
  2. Patau Syndrome. Also there are 47 chromosomes (three 13 chromosomes are marked). The child will have underdevelopment of the brain and a number of internal organs, as well as an abnormal structure of the face, a larger number of fingers on the limbs.
  3. Turner Syndrome. The reason is, on the contrary, a lack of chromosomes, only one X chromosome is present. The anomaly occurs only in girls and manifests itself in the form of short stature, a shield-like chest, pterygoid folds in the neck, deformities of the elbows, auricles, skin pigmentation, varying degrees of mental retardation and other signs.

Children with these chromosomal disorders often die in the first years after birth. In the future, they are usually sterile.

Other possible causes of elevated TVP (not due to chromosomal abnormalities) include:

  1. Heart defects (including those incompatible with life after birth).
  2. Anemia.
  3. Deviations in the structure of the skeleton, the formation of connective tissue.
  4. Hypoproteinemia. This is a reduced amount of protein in the blood plasma.
  5. Disorders in the lymphatic system.

Many of these abnormalities cause infections that enter the body of a pregnant woman in the early stages (for example, cytomegalovirus or tooscoplasmosis).

The good news is that sometimes an increased TVP indicator is simply an individual feature of the child's development, which does not manifest itself in any way after birth. Absolutely healthy babies are born. Thus, if the expectant mother has an excess of TVP, she does not need to be very upset right away, especially if this parameter does not exceed the norm too much.
Sometimes elevated TVP is simply a feature of fetal development and is not associated with any pathology.

Meanwhile, a significant excess with a high degree of probability may indicate precisely a chromosomal abnormality. For example, if an increase in TVP, for example, at 13 weeks is 3-4 mm, then the probability of a child having Down syndrome is 7%, at 5-6 mm - accordingly already 53%, and at 9 mm and more - already as much as 78 %.

Further actions of physicians with increased TVP

If the fetus has an increased TVP, then the doctors prescribe the expectant mother another ultrasound scan in one or two weeks (which is why it is better to take the first measurement early - at a period of 12 weeks). In addition, a woman is recommended to undergo a blood test to identify the risk of chromosomal diseases: determination of the amount of PAPP-A and free beta-hCG, their content in fetuses with an incorrect chromosome set will differ from the norm. The doctor may also examine the umbilical cord fluid and amniotic fluid. A woman, along with this, must be sent for a consultation with a geneticist.

All these procedures are voluntary (as well as ultrasound). The gynecologist does not have the right to forcibly send a pregnant woman to them.

It is better to do analyzes immediately in order to quickly establish the fact of an anomaly. If the assumption is confirmed, the doctor (and often a medical council) suggests the woman to artificially terminate the pregnancy (again, it does not force). Of course, it is better to do this at an earlier date. The final choice rests with the parents. The duty of doctors is to explain in detail to a married couple all the consequences of the birth of a sick child.
If the subsequent examination confirms the diagnosis, the couple will have to make a difficult decision - to terminate the pregnancy or give birth to an unhealthy child.

Video: why TVP can be increased, and what to do in such a situation (explains obstetrician-gynecologist Elena Porozova)

Women's experiences with increased TBI

I was at the upper limit of the norm - 2.9. With my son, everything is fine, although the blood was bad, they offered a puncture, but I did not have time for it, so I didn’t do it.

Anna Zhilina

https://deti.mail.ru/forum/v_ozhidanii_chuda/beremennost/uvelichen_tvp/

First, I went to the screening, at the 12th week, where the doctor immediately told me that it was bad, and very much, since she measured 5 mm. Moreover, the child refused to turn as needed, she crumpled my whole belly while she was measuring and re-measuring. She refused to take blood, said that with such a result, the ultrasound does not see any reason to donate blood. Sent me for a puncture the next morning. There I was still looked at by ultrasound, and through the stomach, and vaginally. They said it was a cyst, since it is visible only from one side. But they also found a cyst on the head! And then, they found the amniotic strands, they could not see the face, as well as the nasal bone. They said that 99% on chromosomes, everything is fine, but the pregnancy should not be carried on further, since the child has rooted with his back to the amniotic strands, and what is there with the face is also impossible to say. A puncture was made anyway, just in case, the result was in 5 days ... everything on the chromosomes is good, but the amniotic cords, especially grown ... this is not a joke. Abortion for medical reasons at 12 weeks.

Elena SK

https://deti.mail.ru/forum/v_ozhidanii_chuda/beremennost/uvelichen_tvp/?page=2

We have increased the TVP. Unfortunately, it all ended sadly. I don’t want to scare, I’ll just tell my story. It happened quite recently. For a period of 11 weeks. and 2 days on 1 ultrasound revealed TVP 3.28 and hypoplasia of the nasal bones in question. To my question "Why?", The doctor said - either chromosomal abnormalities, or heart problems. They took blood, and since it was Friday, they said on Monday to go for a genetic consultation. Sobbed all weekend. On Monday we arrive at the GC. They do an ultrasound scan and a blood test. The blood is normal, but the ultrasound - TVP is already 4.1 and the child has edema all over the body. The risk is set at 1: 556. The doctor suggests a chorionic villus sampling. A week later we arrive for the procedure, and we have a frozen pregnancy. My state cannot be expressed in words. We still do the puncture in order to understand whether the chromosomal failure led to this or not. As a result, there were no abnormalities in chromosomes (46, XX). On the same day, they did a cleaning, but none of the doctors still can tell me what caused the ST. Here's a story.

Elena Ivanova

During my first pregnancy, my TVP was also higher than normal, I decided to recheck and signed up for a second ultrasound, but not in the LCD, but in a better clinic (the equipment is better + reviews) and a week later my husband and I went to the other end of the city, to the doctor at first she did not say that this was a second ultrasound, and only when he said TVP and I realized that everything was within the normal range, I calmed down and said that this was a second ultrasound and on the first one they measured almost 1 mm more.

Natalia Korneeva

https://vk.com/topic-39733006_31669348

At 13 weeks, there was an elevated TVP of 6.0 mm. It was terrifying to me. Sent to genetics. They immediately made a puncture. The analysis came bad, fetal trisomy. The pregnancy was terminated at 18 weeks. We passed the tests for the karyotype, my husband and I, everything is in order with the chromosomes. My advice is to go through all the procedures that are offered.

Natalia Ilikbaeva

https://vk.com/topic-39733006_31669348

Both my twins underwent ultrasound examination with extended TVP, then in MONIAH one child was given 4 mm, the second 3.2, i.e. 1:27 Down syndrome. In the end, at 36 weeks, I gave birth to two healthy girls.

Dimon Dimonov

https://vk.com/topic-39733006_31669348

My son had TVP of 10 mm, I was also immediately sent for an abortion, but I did not agree, the chromosomes were normal, the ultrasound scan at 16 and 22 weeks did not reveal anything serious, but the doctors still said throughout the pregnancy that the child would have something that's not the case. He was born healthy, now he is 2 years old!

Prenatal screening - This is a combined biochemical and ultrasound examination, consisting of a blood test to determine the level of the main hormones of pregnancy and a conventional ultrasound of the fetus with the measurement of several values.

First screening or "double test" (at 11-14 weeks)

Screening includes two stages: an ultrasound scan and taking blood for analysis.

During the ultrasound examination, the diagnostician determines the number of fetuses, gestational age and takes the size of the embryo: CTE, BPD, the size of the cervical fold, nasal bone, etc.

According to these data, we can say how well the baby develops in the womb.

Ultrasound screening and its norms

Estimation of the size of the embryo and its structure. Coccyx-parietal size (CTE)- This is one of the indicators of the development of the embryo, the value of which corresponds to the gestational age.

CTE is the size from the coccyx to the crown of the head, excluding the length of the legs.

There is a table of standard KTP values ​​according to the week of pregnancy (see table 1).

Table 1 - The rate of CTE according to the gestational age

The deviation of the size of the fetus from the norm upwards indicates the rapid development of the baby, which is a harbinger of bearing and giving birth to a large fetus.

Too small size of the fetal body indicates:

  • the initially incorrectly set period of pregnancy by the district gynecologist, even before the visit to the diagnostician;
  • developmental delay as a result of hormonal deficiency, infectious disease or other ailments in the mother of the child;
  • genetic pathologies of fetal development;
  • intrauterine fetal death (but only on condition that fetal heartbeats are not heard).

Biparietal size (BPD) of the fetal head Is a measure of the development of a baby's brain, measured from temple to temple. This value also increases in proportion to the gestational age.

Table 2 - The rate of BPD of the fetal head at a certain gestational age

An excess of the norm for BPD of the fetal head may indicate:

  • large fruit, if the other sizes are also higher than the norm by a week or two;
  • spasmodic growth of the embryo, if the other sizes are normal (after a week or two, all parameters should equalize);
  • the presence of a brain tumor or cerebral hernia (pathologies incompatible with life);
  • hydrocephalus (dropsy) of the brain due to an infectious disease in the expectant mother (antibiotics are prescribed and, with successful treatment, the pregnancy remains).

The biparietal size is less than normal in the case of underdevelopment of the brain or the absence of some of its parts.

The thickness of the collar space (TVP) or the size of the "neck fold"- this is the main indicator that, if abnormal, indicates a chromosomal disease (Down syndrome, Edwards syndrome, or another).

In a healthy child, TBP at the first screening should not be more than 3 mm (for ultrasound performed through the abdomen) and more than 2.5 mm (for vaginal ultrasound).

The value of TVP in itself does not mean anything, it is not a sentence, there is simply a risk. It is possible to speak of a high probability of the development of chromosomal pathology in the fetus only in the case of poor results of a blood test for hormones and when the size of the cervical fold is more than 3 mm. Then, to clarify the diagnosis, a chorionic biopsy is prescribed to confirm or deny the presence of chromosomal abnormalities of the fetus.

Table 3 - Norms of TVP by week of pregnancy

The length of the nose bone. In a fetus with a chromosomal abnormality, ossification occurs later than in a healthy fetus, therefore, with deviations in development, the nasal bone is either absent at the first screening (at 11 weeks), or its size is too small (from 12 weeks).

The length of the nasal bone is compared with the standard value from the 12th week of pregnancy, at 10-11 weeks the doctor can only indicate its presence or absence.

If the length of the nasal bone does not match the gestational age, but the rest of the indicators are normal, there is no cause for concern.
Most likely, this is an individual feature of the fetus, for example, the nose of such a baby will be small and snub-nosed, like that of a parent or one of close relatives, for example, a grandmother or great-grandfather.

Table 4 - The norm of the length of the nasal bone

Also, at the first ultrasound screening, the diagnostician notes whether the bones of the cranial vault, butterfly, spine, limb bones, anterior abdominal wall, stomach, bladder are visualized. At this time, the indicated organs and parts of the body are already clearly visible.

Assessment of the vital functions of the fetus. In the first trimester of pregnancy, the vital activity of the embryo is characterized by cardiac and motor activity.

Since fetal movements are usually periodic and barely distinguishable at this time, only the heart rate of the embryo has diagnostic value, and motor activity is simply noted as “determined”.

Heart rate (HR) fetus, regardless of gender, at 9-10 weeks should be in the range of 170-190 beats per minute, from 11 weeks to the end of pregnancy - 140-160 beats per minute.

Fetal heart rate below normal (85-100 beats / min) or above normal (more than 200 beats / min) is an alarming sign in which additional examination and, if necessary, treatment is prescribed.

Examination of extraembryonic structures: yolk sac, chorion and amnion. Also, the ultrasound diagnostician in the screening ultrasound examination protocol (in other words, in the ultrasound results form) notes data on the yolk sac and chorion, on the appendages and walls of the uterus.

Yolk sac- This is an organ of the embryo, which until the 6th week is responsible for the production of vital proteins, plays the role of the primary liver, circulatory system, primary germ cells.

In general, the yolk sac performs various important functions up to 12-13 weeks of pregnancy, then the need for it disappears, because the fetus is already forming separate organs: the liver, spleen, etc., which will take all the responsibilities of ensuring life. ...

By the end of the first trimester, the yolk sac shrinks in size and turns into a cystic formation (yolk stalk), which is located near the base of the umbilical cord. Therefore, at 6-10 weeks, the yolk sac should be no more than 6 mm in diameter, and after 11-13 weeks, it is normally not visualized at all.

But everything is purely individual, the main thing is that it does not finish its functions ahead of schedule, so for 8-10 weeks it should be at least 2 mm (but not more than 6.0-7.0 mm) in diameter.

If up to 10 weeks the yolk sac is less than 2 mm, then this may indicate an undeveloped pregnancy or a lack of progesterone (then Dufaston or Utrozhestan is prescribed), and if at any time in the first trimester the diameter of the yolk sac is more than 6-7 mm, then this indicates the risk of developing pathologies in the fetus.

Chorion- This is the outer shell of the embryo, covered with many villi that grow into the inner wall of the uterus. In the first trimester of pregnancy, the chorion provides:

  • nutrition of the fetus with the necessary substances and oxygen;
  • removal of carbon dioxide and other waste products;
  • protection against the penetration of viruses and infections (although this function is not durable, but with timely treatment, the fetus does not become infected).

Within normal limits, the localization of the chorion "at the bottom" of the uterine cavity (on the upper wall), on the front, back or one of the side walls (left or right), and the structure of the chorion should not be changed.

The location of the chorion in the area of ​​the internal pharynx (transition of the uterus to the cervix), on the lower wall (at a distance of 2-3 cm from the pharynx) is called chorionic presentation.

But such a diagnosis does not always indicate a placenta previa in the future, usually the chorion "moves" and is thoroughly fixed higher.

Chorionic presentation increases the risk of spontaneous miscarriage, therefore, with this diagnosis, observe bed rest, move less and do not overwork. There is only one treatment: to lie in bed for days (getting up only to use the toilet), sometimes raising your legs up and staying in this position for 10-15 minutes.

By the end of the first trimester, the chorion will become the placenta, which until the end of pregnancy will gradually “mature” or, as they say, “grow old”.

Up to 30 weeks gestation - maturity 0.

This is how the ability of the placenta to provide the baby with everything necessary at every stage of pregnancy is assessed. There is also the concept of "premature aging of the placenta", which indicates a complication of the course of pregnancy.

Amnion- This is the inner aqueous membrane of the embryo, in which the amniotic fluid (amniotic fluid) accumulates.

The amount of amniotic fluid at 10 weeks is about 30 ml, at 12 weeks - 60 ml, and then it increases by 20-25 ml per week, and at 13-14 weeks it already contains about 100 ml of water.

When examining the uterus with an uterus, an increased tone of the myometrium of the uterus (or hypertonicity of the uterus) can be detected. Normally, the uterus should be out of tone.

Often in the ultrasound results, you can see the record "local thickening of the myometrium along the posterior / anterior wall", which means both a short-term change in the muscular layer of the uterus due to a feeling of agitation in a pregnant woman during ultrasound, and an increased tone of the uterus, which is a threat of spontaneous miscarriage.

The cervix is ​​also examined, its pharynx must be closed. The length of the cervix for 10-14 weeks of pregnancy should be about 35-40 mm (but not less than 30 mm for primiparous and 25 mm for multiparous). If it is shorter, it indicates the risk of premature birth in the future. Approaching the day of the expected birth, the cervix will shorten (but should be at least 30 mm by the end of the pregnancy), and before the birth itself, its pharynx will open.

The deviation from the norm of some parameters at the first screening does not give rise to worries, just pregnancy in the future should be observed more closely, and only after the second screening can we talk about the risk of developing fetal malformations.

Standard first trimester ultrasound protocol

Biochemical screening ("double test") and its decoding

Biochemical screening of the first trimester involves the determination of two elements contained in a woman's blood: the level of free b-hCG and plasma protein-A - PAPP-A. These are two hormones of pregnancy and with the normal development of the baby, they should correspond to the norm.

Human chorionic gonadotropin (hCG) consists of two subunits - alpha and beta. Free beta-hCG is unique in its way, therefore its value is taken as the main biochemical marker used to assess the risk of chromosomal abnormalities in the fetus.

Table 5 - The norm of b-hCG during pregnancy by week


An increase in the value of free b-hCG indicates:

  • the risk of the fetus having Down syndrome (if the norm is doubled);
  • multiple pregnancies (hCG levels increase in proportion to the number of fetuses);
  • the presence of diabetes mellitus in a pregnant woman;
  • preeclampsia (i.e., with an increase in blood pressure + edema + detection of protein in the urine);
  • fetal malformations;
  • cystic drift, choriocarcinoma (a rare type of tumor)

A decrease in the beta-hCG value indicates:

  • the risk of the fetus having Edwards syndrome (trisomy 18) or Patau syndrome (trisomy 13);
  • the threat of termination of pregnancy;
  • fetal growth retardation;
  • chronic placental insufficiency.

PAPP-A- pregnancy-associated plasma protein-A.

Table 6 - The norm of PAPP-A during pregnancy by weeks

A low level of PAPP-A in a pregnant woman's blood gives a strong reason to assume that there is a risk:

  • the development of chromosomal pathology: Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), Patai syndrome (trisomy 13) or Cornelia de Lange syndrome;
  • spontaneous miscarriage or intrauterine fetal death;
  • placental insufficiency or fetal malnutrition (i.e., underweight due to malnutrition of the baby);
  • development of preeclampsia (assessed in conjunction with the level of placental growth factor (PLGF). A high risk of developing preeclampsia is indicated by a decrease in PAPP-A together with a decrease in placental growth factor.

An increase in PAPP-A can be observed if:

  • a woman is carrying twins / triplets;
  • the fetus is large and the mass of the placenta is increased;
  • the placenta is low.

For diagnostic purposes, both indicators are important, therefore they are usually considered in combination. So if PAPP-A is reduced and beta-hCG is increased, there is a risk of the fetus having Down syndrome, and with a decrease in both indicators, Edwards syndrome or Patau syndrome (trisomy 13).

After 14 weeks of pregnancy, the PAPP-A test is considered uninformative.

Second trimester screening (at 16-20 weeks)

II screening, as a rule, is prescribed in case of deviations in the I screening, less often with the threat of termination of pregnancy. In the absence of deviations, the second comprehensive screening can not be carried out, but only an ultrasound of the fetus can be performed.

Ultrasound screening: norms and deviations

Screening ultrasound at this time is aimed at determining the "skeletal" structure of the fetus and the development of its internal organs.
Fetometry. The diagnostician notes the presentation of the fetus (pelvic or cephalic) and removes other indicators of fetal development (see table 7 and 8).

Table 7 - Standard sizes of the fetus by ultrasound

As in the first screening, the length of the nasal bone is measured in the second. With normal other indicators, the deviation of the length of the nasal bone from the norm is not considered a sign of chromosomal abnormalities in the fetus.

Table 8 - The norm of the length of the nasal bone

According to the measurements taken, one can judge the true duration of pregnancy.

Fetal anatomy. The Uzist is examining the baby's internal organs.

Table 9 - Standard values ​​of the fetal cerebellum by week

The dimensions of both the lateral ventricles of the brain and the cisterna magna should not exceed 10-11 mm.

Usually, other indicators, such as: Nasolabial triangle, Eye sockets, Spine, 4-chamber cut of the heart, Cut through 3 vessels, Stomach, Intestine, Kidneys, Bladder, Lungs - in the absence of visible pathologies are marked as "normal".

The place of attachment of the umbilical cord to the anterior abdominal wall and to the center of the placenta is considered the norm.

The abnormal attachment of the umbilical cord includes the marginal, membranous and split, which leads to difficulties in the birth process, fetal hypoxia and even its death during childbirth, if a planned CS is not prescribed or during premature birth.

Therefore, in order to avoid fetal death and blood loss in a woman during childbirth, a planned cesarean section (CS) is prescribed.

There is also a risk of developmental delays, but with normal developmental indicators of the baby and careful observation of the woman in labor, everything will go well for both.

Placenta, umbilical cord, amniotic fluid. The placenta is located most often on the back wall of the uterus (more on the right or left can be specified in the form), which is considered the most successful attachment, since this part of the uterus is best supplied with blood.

The zone closer to the bottom also has a good blood supply.

But it happens that the placenta is localized on the front wall of the uterus, which is not considered something pathological, but this area is prone to stretching during the growth of the baby inside the mother's womb, plus the active movements of the baby - all this can lead to placental abruption. In addition, placenta previa is more common in women with an anterior placenta.

This is not critical, just this information is important for deciding on the method of delivery (whether a caesarean section is necessary and what difficulties may arise during childbirth).

Normally, the edge of the placenta should be 6-7 cm (or more) above the internal pharynx. Abnormal is considered to be its location in the lower part of the uterus in the area of ​​the internal pharynx, partially or completely overlapping it. This phenomenon is called "placenta previa" (or low placenta).

It is more informative to measure the thickness of the placenta after the 20th week of pregnancy. Until this time, only its structure is noted: homogeneous or heterogeneous.

From 16 to 27-30 weeks of pregnancy, the structure of the placenta should be unchanged, homogeneous.

A structure with an expansion of the intervillous space (MVP), echo-negative formations and other kinds of abnormalities negatively affects the nutrition of the fetus, causing hypoxia and developmental delay. Therefore, treatment is prescribed Curantil (normalizes blood circulation in the placenta), Actovegin (improves the supply of oxygen to the fetus). With timely treatment, babies are born healthy and on time.

After 30 weeks, there is a change in the placenta, its aging, and as a result, heterogeneity. At a later date, this is already a normal phenomenon that does not require additional examinations and treatment.

Normally, up to 30 weeks, the degree of maturity of the placenta is "zero".

Amniotic fluid. To determine their number, the diagnostician calculates the amniotic fluid index (AFI) according to measurements made during ultrasound.

Table 10 - Norms of the amniotic fluid index by week

Find your week of pregnancy in the first column. The second column indicates the range of the norm for this period. If the AFI, indicated by the uzist in the screening results, is included in this range, then the amount of amniotic fluid is normal, less than the norm means early oligohydramnios, and more - polyhydramnios.

There are two degrees of severity: moderate (insignificant) and severe (critical) oligohydramnios.

Severe oligohydramnios threatens with abnormal development of fetal limbs, deformity of the spine, and the baby's nervous system also suffers. As a rule, babies who have suffered from oligohydramnios in the womb lag behind in development and weight.

With severe lack of water, drug treatment must be prescribed.

Moderate oligohydramnios usually does not require treatment, it is only necessary to establish nutrition, minimize physical activity, take a vitamin complex (it must include vitamin E).

In the absence of infections, preeclampsia and diabetes mellitus in the mother of the child, and with the development of the baby within the normal range, there is no reason for worry, most likely, this is a feature of the course of this pregnancy.

Normally, the umbilical cord has 3 vessels: 2nd artery and 1st vein. The absence of one artery can lead to various pathologies in the development of the fetus (heart disease, esophageal atresia and fistula, fetal hypoxia, disruption of the genitourinary or central nervous system).

But about the normal course of pregnancy, when the work of the missing artery is compensated by the existing one, we can talk about:

  • normal blood test results for hCG, free estriol and AFP, i.e. in the absence of chromosomal pathologies;
  • good indicators of fetal development (according to ultrasound);
  • the absence of defects in the structure of the fetal heart (if an open functional oval window is found in the fetus, you should not worry, it usually closes for up to a year, but it is necessary to be observed by a cardiologist every 3-4 months);
  • not disturbed blood flow in the placenta.

Babies with such an anomaly as the "single artery of the umbilical cord" (abbreviated as EAP) are usually born with a small weight and can often get sick.

Up to a year, it is important to monitor the changes in the child's body, after a year of life, the crumbs are recommended to thoroughly take care of his health: organize a proper balanced diet, take vitamins and minerals, perform immunity-strengthening procedures - all this can bring the state of a small body in order.

The cervix and walls of the uterus. In the absence of abnormalities, the ultrasound protocol will indicate “Cervix and uterine walls without features” (or abbreviated as b / o).

The length of the cervix in this trimester should be 40-45 mm, 35-40 mm is acceptable, but not less than 30 mm. If its opening and / or shortening is observed in comparison with the previous measurement with ultrasound or softening of its tissues, which is collectively called "isthmic-cervical insufficiency" (ICI), then the installation of an obstetric unloading pessary or suture is prescribed to preserve the pregnancy and reach the prescribed term.

Visualization. Normally, it should be "satisfactory". Visualization is difficult when:

  • the position of the fetus is inconvenient for the study (the baby is just positioned so that not everything can be seen and measured, or he was constantly spinning during the ultrasound);
  • overweight (the reason is indicated in the visualization column - due to subcutaneous fatty tissue (SFA));
  • swelling in the expectant mother
  • hypertonicity of the uterus during ultrasound.

Standard second trimester ultrasound protocol

Biochemical screening or "triple test"

Biochemical screening of blood in the second trimester is aimed at determining three indicators - the level of free b-hCG, free estriol and AFP.

Free beta-hCG rate look at the table below, and you will find the decryption, it is the same at each stage of pregnancy.

Table 11 - The rate of free b-hCG in the second trimester

Free estriol Is one of the pregnancy hormones that reflects the functioning and development of the placenta. In the normal course of pregnancy, it progressively grows from the first days of the beginning of the formation of the placenta.

Table 12 - Rate of free estriol by week

An increase in the amount of free estriol in the blood of a pregnant woman is observed with multiple pregnancies or high fetal weight.

A decrease in the level of estriol is observed in fetoplacental insufficiency, the threat of termination of pregnancy, cystic drift, intrauterine infection, adrenal hypoplasia or anencephaly (neural tube defect) of the fetus, Down syndrome.

A decrease in free estriol by 40% or more from the standard value is considered critical.

Taking antibiotics during the test period can also affect a decrease in estriol in a woman's blood.

Alpha-fetoprotein (AFP) Is a protein produced in the liver and gastrointestinal tract of the baby, starting from the 5th week of pregnancy from conception.

This protein enters the mother's blood through the placenta and from the amniotic fluid, and begins to build up in it from the 10th week of pregnancy.

Table 13 - Norm of AFP by weeks of pregnancy

If during pregnancy a woman was sick with a viral infection, and the baby had liver necrosis, then an increase in AFP in the serum of the pregnant woman is also observed.

Third screening (at 30-34 weeks)

In total, two screenings are carried out during pregnancy: in the first and in the second trimesters. In the third trimester of pregnancy, a kind of final control over the state of the fetus's health is carried out, its position is monitored, the functionality of the placenta is assessed, and a decision is made on the method of delivery.

For this, somewhere at 30-36 weeks, an ultrasound scan of the fetus is prescribed, and from 30-32 weeks cardiotocography (abbreviated CTG - registration of changes in the fetal cardiac activity, depending on its motor activity or uterine contractions).

Doppler sonography can also be prescribed, which allows you to assess the strength of blood flow in the uterine, placental and great vessels of the fetus. With the help of this study, the doctor will find out if the baby has enough nutrients and oxygen, because it is better to prevent the appearance of fetal hypoxia than to solve the health problems of the baby after childbirth.

It is the thickness of the placenta, along with the degree of maturity, that shows its ability to supply the fetus with everything it needs.

Table 14 - Placenta thickness (norm)

With a decrease in thickness, the diagnosis of "placental hypoplasia" is made. Usually this phenomenon causes late toxicosis, hypertension, atherosclerosis or infectious diseases suffered by a woman during pregnancy. In any case, treatment or supportive therapy is prescribed.

Most often, placental hypoplasia is observed in fragile miniature women, because one of the factors in reducing the thickness of the placenta is the weight and physique of the pregnant woman. This is not scary, more dangerous is an increase in the thickness of the placenta and, as a consequence, its aging, which indicates a pathology that can lead to abortion.

The thickness of the placenta increases with iron deficiency anemia, gestosis, diabetes mellitus, Rh-conflict and with viral or infectious diseases (transferred or present) in a pregnant woman.

Normally, a gradual thickening of the placenta occurs in the third trimester, which is called aging or maturity.

Placenta maturity (normal):

  • 0 degree - up to 27-30 weeks;
  • 1st degree - 30-35 weeks;
  • 2nd degree - 35-39 weeks;
  • Grade 3 - after 39 weeks.

Early aging of the placenta is fraught with a deficiency of nutrients and oxygen, which threatens fetal hypoxia and developmental delay.

An important role in the third trimester is played by the amount of amniotic fluid. Below is a normative table for the amniotic fluid index - a parameter that characterizes the amount of water.

Below is a table of the standard sizes of the fetus by week of pregnancy. The kid may not correspond a little to the specified parameters, because all children are individual: someone will be large, someone will be small and fragile.

Table 16 - Standard size of the fetus by ultrasound for the entire period of pregnancy

Preparation for screening ultrasound

Transabdominal ultrasound - the sensor is guided along the abdominal wall of a woman, transvaginal ultrasound - the sensor is inserted into the vagina.

With transabdominal ultrasound, a woman with a period of up to 12 weeks of pregnancy should come for diagnosis with a full bladder, having drunk 1-1.5 liters of water half an hour or an hour before visiting an ultrasound doctor. This is necessary so that a full bladder "squeezes" the uterus out of the pelvic cavity, which will give a better view of it.

From the second trimester, the uterus increases in size and is well visualized without any preparation, so there is no need for a full bladder.

Take a handkerchief with you to wipe the rest of the special gel from your abdomen.

With transvaginal ultrasound, it is first necessary to carry out hygiene of the external genital organs (without douching).

The doctor can tell in advance to purchase a condom from the pharmacy, which is put on the sensor for hygiene purposes, and go to the toilet to urinate if the last urination was more than an hour ago. To maintain intimate hygiene, take with you special wet wipes, which you can also purchase in advance at the pharmacy or in the store at the appropriate department.

Transvaginal ultrasound is usually performed only in the first trimester of pregnancy. With the help of it, it is possible to detect a fertilized egg in the uterine cavity even before the 5th week of pregnancy, abdominal ultrasound is not always possible at such an early stage.

The advantage of vaginal ultrasound is that it can determine an ectopic pregnancy, the threat of miscarriage in case of pathology of the location of the placenta, diseases of the ovaries, fallopian tubes, uterus and its cervix. Also, vaginal examination makes it possible to more accurately assess how the fetus is developing, which can be difficult to do in overweight women (if there is a fold of fat on the abdomen).

For ultrasound, it is important that gases do not interfere with the examination, therefore, in case of flatulence (bloating), it is necessary to take 2 Espumisan tablets after each meal the day before the ultrasound scan, and in the morning on the day of the examination, drink 2 Espumisan tablets or a Smecta bag, spreading it to the floor a glass of water.

Preparing for biochemical screening

Blood is taken from a vein, preferably in the morning and always on an empty stomach. The last meal should be 8-12 hours before sampling. In the morning on the day of blood sampling, you can drink only mineral water without gas. Remember that tea, juice and similar liquid are also food.

Comprehensive screening cost

If a planned ultrasound examination in city antenatal clinics is most often carried out for a small fee or completely free of charge, then prenatal screening is an expensive set of procedures.

Biochemical screening alone costs from 800 to 1600 rubles. (from 200 to 400 UAH.), depending on the city and laboratory "plus", for a regular ultrasound of the fetus, you need to pay somewhere around 880-1060 rubles. (220-265 UAH). In total, a comprehensive screening will cost at least 1,600 - 2,660 rubles. (420-665 UAH).

It makes no sense to conduct prenatal screening at any stage of pregnancy if you are not ready to have an abortion if doctors confirm that the fetus has mental retardation (Down's syndrome, Edwards, etc.) or malformations of any organs.

Comprehensive screening is designed for early diagnosis of pathologies in the intrauterine development of the fetus, so that only healthy offspring can be produced.