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First screening at 14 weeks pregnant. Screening of the first trimester of pregnancy - what you need to know about the rates and results

Ultrasound screening is a complete set of examinations that allows mom and dad to find out about the health status of a baby in the womb. This method allows you to see the presence or absence of many congenital diseases. Usually it is done three times during pregnancy - in the first, second and third trimester. It consists of two procedures - ultrasound diagnostics and blood tests.

First trimester screening consists of ultrasound and blood test

The first screening is done between 11 and 14 weeks after conception. The main task of the method is to check the fetus for the presence of any pathologies in development.

This method of verification even reveals complications in pregnancy, which future mom could not suspect due to the absence of symptoms, good health, etc. This study is not always made pregnant, often other groups of people undergo it.

For example, screening a group of children of the same age - the technique allows you to identify characteristic diseases for this age. Since it is usually prescribed only three times, it scares women if a specialist sends for additional screening.

There is no reason to panic, because doctors are sent for an additional examination not because of the detection of a pathology, but because there is a risk of its development. For example, screening is often prescribed for women over 35 years old if family members have pathologies, if there was a miscarriage or miscarriage in the past, etc.

How is the study carried out and for how long?

To obtain reliable results, the first examination is prescribed between the eleventh and thirteenth weeks of pregnancy. Before or after this period, it is impossible to pass the test, otherwise there is a chance not to see the pathology.

It is possible to refuse planned examinations during pregnancy, but this will be considered negligent to your health. Such a decision carries a risk for the child. Refusing scheduled checks, a woman puts his life in danger.

The procedure consists of two stages:

Diagnostics by ultrasound;
Study of blood biochemistry.

There are rules for undergoing an ultrasound examination - an expectant mother an hour and a half before the examination is obliged to drink half a liter of ordinary, clean, non-carbonated water. The bladder during ultrasound should be full so that the specialist can better examine the position of the fetus and its condition. Instead of drinking water, you can not urinate three hours before the examination.

When a specialist uses a transvaginal fetal examination method, the sensor is inserted into the vagina, so the preparation described above is not required. However, it is advisable to go to the toilet before that.

After ultrasound, a blood biochemistry test is done. It is this order that is required, since blood counts can change very quickly, but if you undergo an ultrasound examination before that, then it will be possible to establish the condition of the baby without any problems.

A pregnant woman should go for blood donation with the results of an ultrasound, where the gestational age will be indicated. Unfortunately, sometimes ultrasound shows pregnancy regression or fading, then blood donation will no longer be needed. To prepare for blood sampling, you need to drink only clean water, exclude food and any drinks - blood sampling takes place on an empty stomach.

The specialist will conduct an ultrasound, the results of which will confirm or refute the presence of pathologies

What can be learned from screening?

Often, specialists cannot immediately consider all the data, so they ask the expectant mother to turn on the other side, walk around, cough, or even squat. Thus, the fetus changes position.

The specialist examines the following indicators:

Coccyx-parietal size, or CTE. It is carried out from the parietal point on the fetal head to the coccyx.
Biparietal size, or BDP - a study of the distance between the tubercles of the crown zone.
Measure the circumference of the head and the distance from the back of the head to the forehead.
They check the structure of the brain, whether the hemispheres are symmetrical, whether the cranium is closed.
Check the thickness of the collar zone, or TVP.
They study the frequency of contractions of the heart muscle, its size and the size of large vessels.
Check the length of the bones of the shoulders, thighs, lower leg and forearm.
The thickness of the placenta and its structure, as well as its location in the uterus.
The location of the umbilical cord and the number of vessels in it.
Quantity amniotic fluid.
Tone of the uterus.
Condition of the cervix.

If the study is carried out earlier than at the eleventh week, then not all organs and bones are still sufficiently formed so that the specialist can check them for abnormalities.

Starting biochemistry, it turns out to determine some important indicators, for example, chorionic gonadotropin β-hCG. This hormone is produced by the fetus. Interestingly, it is with its help that you can determine the presence of pregnancy.

3D ultrasound examination is now possible

If a girl is in position and does a test, then a special substance on the test strip reacts to the presence of a hormone. From the beginning of the first days of pregnancy (if it proceeds without complications), the amount of hormone produced gradually increases, reaching a peak by the twelfth week. Further, the level of the hormone begins to gradually fall. In the second half of the term, the indicators of β-hCG remain unchanged.

Below is the norm of β-hCG indicators by week:

tenth - from 25.80 to 181.60 ng / ml;
eleventh, from 17.4 to 130.3 ng/ml;
twelfth - from 13.4 to 128.5 ng / ml;
thirteenth - from 14.2 to 114.8 ng / ml.

If the indicators exceed the norm, then there are several options - Down syndrome in a child, the mother suffers from severe toxicosis, or she has diabetes.

If the indicators are below the norm, then this also indicates several problems: placental insufficiency, threats of miscarriage, ectopic pregnancy or Edwards syndrome in a child. Another important indicator in the blood is protein-A. Protein is responsible for the proper development and functioning of the placenta.

Below is the norm of protein-A (PAPP-A) indicators by week:

tenth - from 0.45 to 3.73 mU / ml;
eleventh - 0.78 to 4.77 mU / ml;
twelfth - from 1.03 to 6.02 mU / ml;
thirteenth - from 1.47 to 8.55 honey / ml.

When the indicators are below normal, this may signal the presence of such abnormalities as Down syndrome, Edwards or Cornelia de Lange. But there are also cases when an elevated protein level does not signal the presence of the pathologies listed above.

Rules for preparing for the study

Always have an ultrasound first. There are two types of ultrasound examination - transabdominal and transvaginal. The first is carried out, as usual, by moving the sensor along the belly of the pregnant woman. During the second, the probe is inserted into the vagina.

In the first case, it is necessary to go to the procedure with full bladder- drink about one and a half liters of pure water without gas in half an hour. The second method does not involve any special preparatory measures. When the results of the ultrasound are issued, the woman must donate blood for analysis. It is taken from a vein, so be sure to take it on an empty stomach and do not drink drinks other than water.

To get the most reliable results, a pregnant woman must exclude sweet, smoked, fried and fatty foods from her menu three days before the analysis, as well as foods that cause allergies - citrus fruits, chocolate, nuts and seafood.

During a transabdominal examination, you need to drink one and a half liters of water or not go to the toilet for several hours

Screening for the first trimester of pregnancy

As already written above, it is carried out no earlier than the eleventh, but no later than the thirteenth week. It is during this period that the so-called embryonic period of fetal development ends, and the fetal period begins.

This means that from an embryo turns into a fetus, organs are already beginning to develop, like in a full-fledged person. During this period, pathologies or deviations can be detected.

Of course, only a specialist will correctly decipher the screening results, but expectant mothers can at least in general terms know what to expect and what some indicators can mean.

Who is referred for 1st trimester screening?

You can opt out of screening, but doctors advise against it

All pregnant women are referred, but this procedure can be waived. Doctors do not recommend refusing, as this is a negligent attitude to the life of the baby. The following groups of women should also be screened:

over 35 years old;
there were unsuccessful attempts to give birth - a fetus, a miscarriage;
those who work in industries and may come into contact with harmful substances;
who gave birth to a child with disabilities in the past;
during the first weeks who had an infection;
taking drugs prohibited for the first trimester;
suffering from alcoholism or drug addiction;
when there is a threat;
if there are pathologies in the family.

How the study is done

There is a special medical worker, a sonologist, who performs the procedure. At this time, there are two options - abdominal and transvaginal examination. The second one is preferred because it is more reliable.

There are machines for home ultrasound

The woman is asked to undress to the waist and lie down on the couch with her legs bent. Then a thin probe in a condom is inserted into the vagina. They will be moved to fully examine the fetus, which may be uncomfortable but not painful. After the procedure, some discharge may appear on the linen, possibly a little bloody.

This is normal, no need to worry. Ultrasound of the abdomen does not give reliable results at this time, but if it is chosen, then the woman is asked to lift her clothes to open her stomach. Then you have to wait for the results - in public hospitals up to five days. After that, you need to donate blood for analysis.

1st trimester screening price

It is known that not even all state institutions are ready to provide such a service for free. The blood biochemistry alone exceeds one and a half thousand rubles, and you also have to pay for the ultrasound procedure itself. Each clinic sets the cost in its own way, but it is unlikely to be lower than two thousand rubles.

Deciphering the screening of the 1st trimester by ultrasound, norms and possible deviations

To accurately obtain reliable results, the following conditions are met:

the process occurs only from 12 to 13 weeks;
the fetus must be in the correct position - if something interferes, the doctor will ask you to move, then the baby will roll over;
coccygeal-parietal size (hereinafter in the KTR article) is at least 45 mm.

Various indicators, such as the length of the nasal bone, can indicate an illness in a child.

PAPP-A - what is it?

This indicator in biochemical analysis is a protein that is produced by the placenta. If its indicator is exceeded or it is not enough in the body of a pregnant woman, then this may be a signal for the development of a pathology of a genetic nature.

Human chorionic gonadotropin (hCG)

A hormone produced by the chorion. Immediately after conception, in the very first hours, its level begins to rise. Until 11-12 weeks, the initial figure grows thousands of times.
Then the production of the hormone slows down - somewhere at the beginning of the second trimester, and then remains unchanged.

An increase in the rate may indicate:

Down syndrome;
multiple pregnancy;
the development of diabetes in the mother;
for toxicosis.

The deficiency indicates:

Edwards syndrome in a baby;
risk of miscarriage;
placental insufficiency.

Remember, only a specialist can correctly determine the risk.

What is KTP during pregnancy on ultrasound

This is the coccyx-parietal size, which identifies the correct development of the baby inside the mother's womb. The size of the CTE is compared with the weight of the child and the gestational age. It is believed that the higher this indicator, the longer the gestational age.

KTR norms

When the KTR is above the norm, then the child at birth will weigh more than 3-3.5 kilograms.

But if the indicator is lower, then:

There is a risk that the pregnancy develops abnormally. Then you should check the baby's heartbeat to make sure that he did not die in the womb. If this happens, urgent hospitalization is necessary.
You may not be producing enough hormones, especially progesterone. In this case, the specialist sends for further examination and prescribes medication.
Mom can suffer from an infectious disease, even from a venereal disease.
There is a genetic disorder.

In some cases, a low CTE signals an incorrectly set gestational age.

Fetal BDP (biparietal size)

Thus, the size of the fetal head is measured. It is this indicator that is considered the main one when determining the correctness of child development.

This indicator also determines whether childbirth will be normal or will have to be done. C-section. If the head is too large, then the mother will not be able to give birth to him in the usual way, only through caesarean.

Collar space thickness (TVP)

This place is located between the neck and the upper skin membrane of the fetal body, there is an accumulation of fluid in it. This indicator begins to decrease from the 14th week, and by the 16th it is practically not visible. There are rules that indicate the presence or absence of deviations. To do this, measure the thickness of this space.

The timing of screening is determined by the timing of fetal development

Signs of Down syndrome, as well as Edwards and Patau

A sign of Down syndrome can be considered a decrease in the level of protein-A (PAPP-A), reduced or high hCG. These same signs can also signal Edwards syndrome, therefore, in the case of such results, the pregnant woman is sent for additional examinations.

Nasal bone at 12 weeks, table of norms

With a genetic deviation, it develops incorrectly, more precisely, it ossifies later than usual. If it is too small, or not at all, there may be an anomaly in development. There is a special table of norms.

Heart rate (HR)

In the first stages of life, it is normal when the baby's heart rate is equal to the mother's pulse rate - about 83 beats. But the higher the term, the higher the frequency of contractions. Every day, about three beats per minute will be added. Closer to the 9th week, the frequency is 175 beats per minute.

What can distort the result

False positive results occur in such cases:

Artificial insemination.
Excess weight increases the concentration of all hormones, lack - reduces.
At multiple pregnancy.
With diabetes.
Even stress and fear of the procedure can affect the result, so it is necessary to carry out the procedure in a calm state.

The doctor will explain to you all the indicators of the norm and tell you who to contact if something is wrong

What is risk and how is it calculated?

The risk of developing pathology is calculated for each woman individually, because many parameters influence this - age, bad habits, weight, etc. All data about the woman, as well as the results of screening, are entered into a computer program that calculates the risk.

What if I am at high risk?

If a child is at risk of developing Down syndrome, then there is no need to panic. You should consult a geneticist, he will consider the situation in more detail.

How to confirm or refute the results of screening?

You have the right to be screened again if you think previous results are incorrect. But you will have to undergo an examination in another clinic and only if the gestational age is not higher than 13 weeks.

The doctor says I need to have an abortion. What to do?

No one has the right to force you to terminate a pregnancy if you are at risk of developing Down syndrome. Tell your doctor that you want to see a geneticist. He will send you for one of the procedures - a chorionic villus biopsy (in case of pregnancy for a period of 10 to 13 weeks), or an amniocentesis (16-17 weeks).

Second screening during pregnancy, when to do and what is included in the study

As with the first screening, the second screening will also require an ultrasound and blood test. It occurs from 16 to 20 weeks of pregnancy.

Even with a poor screening result, you should not get upset ahead of time - you can go through the procedure again

Third screening during pregnancy

If the previous two screenings showed no deviations, then the pregnant woman will only have to undergo an ultrasound diagnosis, and she will not need to donate blood (but usually they insist on this).

In addition, you need to go through the following procedures:

dopplerography - evaluates the vessels of the placenta;
cardiotocography - determines the heart rate;
blood biochemistry.

Timing of the third screening during pregnancy

The decision is made by the doctor, more often he prescribes an examination at the 32nd week, but you can go through it already from the 28th up to the 34th.

Where to take the study

Both private clinics and public ones offer this service. However, it will be paid public institution, and in private.

The first perinatal screening is a comprehensive diagnosis of the future mother, which is carried out even before the birth of the baby from 10 to 13–14 weeks of intrauterine development. A classic study of this kind combines only 2 main types of medical manipulations - biochemical analysis maternal serum and fetal ultrasound.

Upon completion of the tests, the obtained data will be monitored, based on a comparison of the result with the indications of the screening norm for ultrasound of the 1st trimester. The main task of an individual examination is the early detection of genetic pathologies in the fetus.

Indications for carrying out

Despite the fact that the primary diagnosis is carried out for many pregnant women, there are special categories of patients who are primarily required to undergo an ultrasound scan and take a blood test in order to eliminate the danger to the life of the unborn child and their own health. This group of people includes expectant mothers who:

have previously given birth to children with any developmental disabilities;
already have a child with fixed genetic pathologies;
crossed the threshold of 35–40 years;
exposed during gestation infectious diseases;
have ever suffered from excessive use of alcohol or drugs;
have a history on hand with notes about the threat of spontaneous miscarriage;
are with the potential father of the baby in a closely related union;
accepted for any reason medications prohibited for use during gestation;
know about the presence of hereditary anomalies in the pedigree of the family;
have experienced a stillbirth in the past;
received a diagnosis indicating the cessation of the development of the child;
show an independent desire to analyze the risk of having an infant with special forms of the disease.

Smoking during pregnancy is the basis for mandatory screening in the first trimester

How are the results of a fetal screening ultrasound deciphered?

Ultrasound diagnostics are prescribed, as a rule, from 10–11 weeks to 13–14 weeks, since this period of the obstetric period provides the first real opportunity to study the basic structures of the emerging baby. 11-12 weeks is a special period characterized by the transformation of the embryo into a fetus.

There is a list of the most important indicators of fetal development, which formed the basis for decoding the conclusion of the ultrasound. These include: KTP, PAPP-A, heart rate, BDP, TVP, hCG, NK, etc. In order to establish an accurate prediction of the course of pregnancy, a specialist needs to compare the personal data of his patient obtained during the first screening with the approved standards that are prescribed in the respective tables.

Coccyx-parietal size

KTP is one of the most important indicators of 1 screening during pregnancy. This parameter indicates the length of the embryo / fetus, which is measured from the crown (top of the head) to the coccygeal bone. In the case of deviations of the CTE from its normal range, it can be assumed that the intrauterine development of the unborn child is endangered.

According to medical observations, the digital designation of the coccygeal-parietal size increases as the gestational age increases. Sometimes a decrease in the index in question indicates an incorrectly established age of the fetus. In this case, we can talk about one of the varieties of the norm. In order to make sure of the diagnosis, the patient should sign up for the 2nd ultrasound appointment.

KTP is one of the main indicators of the condition of the fetus

Heart rate

Regular medical monitoring is necessary for the state of heart rate, since if there are pathological processes in the baby's body, they will be detected in time. If the anomaly is detected at an extremely early stage of its development, the likelihood of a favorable outcome will increase.

Up to 3-4 weeks, the baby's SS rhythm matches the mother's heart rate. The average value is in the range from 76 to 84 beats per minute during the normal functioning of the woman's body.

Further, when the fetal heart structure passes to new stage natural improvement, the number of its contractions will begin to increase evenly. Every 24 hours, the value will exceed the previous "record" by approximately 2.5-3 units. So, by 8–9 weeks, the heart rate of a child developing according to the approved norm will reach 172–176 beats / min.

If before the 83–85th day of gestation, using ultrasound diagnostics, such dangerous phenomena as fetal deformity or the complete absence of a heartbeat were not recorded, then a missed pregnancy can be excluded from the list of possible pathologies. The subsequent phases of body formation are less difficult than a 12-week "Spartan marathon".

Provided that improved and high-quality models of medical devices are used for screening, potential parents will be able to get a more informative characterization of the child's current condition. It is not worth resorting to 3D / 4D ultrasound without special need. Such modern devices, although they can register the intrauterine activity and appearance of the baby, but their radiation dose during the abuse of ultrasound can adversely affect the health of the child.

nasal bone length

Changes in the structure of the oblong nasal bone also indicate the presence of abnormalities. Examining the state of fetuses diagnosed with congenital ailments, scientists came to the conclusion that a genetic failure is often expressed in the underdevelopment of the bone structures of the nose. The first screening during pregnancy to determine the length of the nasal bone (NC) is performed no earlier than 12-13 weeks. If the doctor scheduled an ultrasound session at 10-11 weeks of pregnancy, this means that he only needs to make sure that the nasal bone is present.

In medical practice, there are often significant deviations from the norm of ultrasound, which in fact turned out to be a manifestation of the individuality of the unborn child. In this case, the performance of other tests will comply with the standard.

Collar space thickness

The main task of the TVP study is to measure the thickness of the fold located on the back of the neck. When the main organ systems are formed in the fetus, the region of the collar space begins to fill with a special fluid, the amount of which is subjected to careful analysis.

If the indicator at the first screening exceeded a thickness of 3 millimeters, then it is possible to suspect damage to chromosome segments with a high degree of probability.

Study of the structure of the yolk sac

In simple terms, the yolk sac is a temporary organ that helps maintain the life of the embryo at the initial stage of its formation. From the moment of conception, this important neoplasm is several times larger than the size of the future baby.

It should be noted that the detection of deformation of the yolk vesicle or an overestimated / decreased indicator during screening, in most cases, indicates the development of a dangerous disease, for example, Down syndrome. Sometimes, under such circumstances, a missed pregnancy is diagnosed - the premature death of the embryo.

The 1st screening should not be neglected, since with its help the sonologist will be able to examine the unique structure more closely, making appropriate conclusions about its condition. If the yolk sac is at risk of destruction, immediate medical attention is needed. This is due to the fact that the bubble formed only for 3-3.5 months controls many processes in the child's body.

Its most notable features include:

isolation of extremely important protein structures involved in the construction of protective membranes for embryonic cells;
the formation of a capillary network and red blood cells, which will become the "foundation for laying" the circulatory system of the fetus;
temporary replacement of the liver;
determination of the sex of the child by delivering to him the gametes developed in the cavity of the yolk sac.

Also, this organ is responsible for protecting the small organism from the mother's antibodies. No matter how ambiguous it may sound, but the cells of the woman's immune system, like soldiers on guard of human health, attack the fetus, seeing it as a potential threat - a foreign element. In order to provide the embryo with a safe environment, the yolk sac actively secretes hormones that begin to participate in the process of lowering blood pressure, “pacifying” immune resistance and preparing the mammary glands for breastfeeding.

After 12-14 weeks, the bubble stops its activity, gradually transforming into a cyst-like inclusion, localized near the umbilical cord

Location of the placenta

The localization of the placenta affects the course of the upcoming pregnancy, therefore, with a comprehensive examination, it is given a lot of time. According to the medical standard, this organ should not be located in the lower region of the uterus, since its abnormal structure provokes the overlap of the birth canal. Such a frequent gynecological deviation is called presentation.

Detection of the disease at the first screening with early pregnancy is not always a cause for concern. At an early stage, there is still a chance to change the extremely precarious position - in the subsequent time of gestation, the uterus may rise, while taking its proper place. If a favorable outcome is not observed, doctors begin to develop a detailed action plan, which implies individual indicators for a particular patient.

Biparental fetal head size

BDP is an extremely important index, also registered in the results of the first screening. Without going into the details of medical terminology, we can say that this indicator involves measuring the head along the minor axis - the distance from one temporal bone to another. The biparental size of the fetus is of particular value, primarily because of the direct relationship to the brain located in the cranium.

Since this organ is the main element of the central nervous system, as well as the central processor of the body system, its condition is monitored with special attention by a specialist conducting ultrasonography.

If there are no suspicious signs in the final screening data, then the brain develops in the normal mode. A lower index indicates a lack of any parts of the brain or a delay in its development.

Blood chemistry

After the results of ultrasound diagnostics are obtained, on the basis of which the actual gestational age is determined, the pregnant woman will have to go through the final stage of the perinatal examination - blood biochemistry. Screening involves conducting 2 tests, each of which helps to identify elements of protein origin - PAPP-A and hCG.

2-3 days before the blood biochemistry of the expectant mother, it is recommended to reduce the amount of consumption of fast food, spices, nuts, fatty foods, chocolate and confectionery

PAPP-A is a special hormone (plasma protein A) responsible for the gradual and safe development of the child in the womb. Usually, indicators of its content are found out only from 12–13 weeks, however, as an exception, the blood sampling procedure is carried out a little earlier.

Chorionic gonadotropin is also a hormone that, unlike protein A, begins to be produced immediately after conception. It is noteworthy that its amount actively reaches its maximum value at 11-12 weeks, then the level of hCG content gradually drops, fixing at a stable rate.

As soon as the patient passes perinatal screening in full, doctors will begin to compare the identified indices with the norm, making a full-fledged final conclusion.

What pathologies can be detected at the 1st screening?

With the help of a comprehensive study in the first trimester, you can find a fairly impressive list of pathologies that cause complications of various severity, starting with the deformation of an organ and ending with the death of a baby. The most commonly diagnosed ailments include:

hydrocephalus;
glioma;
Down syndrome;
cerebral hernia;
astrocytoma;
Shershevsky-Turner syndrome;
omphalocele;
aneurysm;
Patau syndrome;
bradycardia;
meningocele;
intrauterine infection;
Edwards syndrome;
hypoxia;
tachycardia;
Smith-Opitz syndrome;
developmental delay;
anemia;
hemimelia (underdevelopment of the limbs);
Cornelia de Lange syndrome;
heart disease.

The above congenital diseases have the right to diagnose only a doctor, since the decoding of ultrasound performed by the patient on his own may be done incorrectly. The formation of a diagnosis based on the indicators of the first screening implies a comprehensive qualitative analysis of all the data obtained, taking into account each aspect and the "pitfall". That is why expectant mothers are advised to trust their health and the life of the baby only to a professional in their field. The constructive unity of the patient with the attending physician increases the likelihood of having a healthy child.

Almost every pregnant woman has heard something about screening for the first trimester of pregnancy (prenatal screening). But often even those who have already passed it do not know what exactly it is prescribed for.

And for expectant mothers who have yet to do this, this phrase in general sometimes seems frightening. And it frightens only because the woman does not know how it is done, how to interpret the results obtained later, why the doctor needs it. You will find answers to these and many other questions related to this topic in this article.

So, more than once I had to deal with the fact that a woman, having heard an incomprehensible and unfamiliar word screening, began to draw terrible pictures in her head that frightened her, making her want to refuse to carry out this procedure. Therefore, the first thing we will tell you is what the word “screening” means.

Screening (English screening - sorting) - these are various research methods that, due to their simplicity, safety and availability, can be used massively in large groups of people to identify a number of signs. Prenatal means prenatal. Thus, we can give the following definition of the concept of "prenatal screening".

Screening of the first trimester of pregnancy is a set of diagnostic studies used in pregnant women at a certain gestational age to detect gross fetal malformations, as well as the presence or absence of indirect signs of fetal pathologies or genetic abnormalities.

The allowable period for 1st trimester screening is 11 weeks - 13 weeks and 6 days (see). Screening is not carried out earlier or later, as in this case the results obtained will not be informative and reliable. Most optimal time 11-13 obstetric weeks of pregnancy are considered.

Who is referred for first trimester screening?

According to order No. 457 of the Ministry of Health Russian Federation 2000, prenatal screening is recommended for all women. A woman can refuse it, no one will forcibly lead her to these studies, but doing this is extremely reckless and speaks only of the woman's illiteracy and negligent attitude towards herself and, above all, towards her child.

Risk groups for whom prenatal screening should be mandatory:

Women who are 35 years of age or older.
The presence of a threat of termination of pregnancy on early dates.
Spontaneous (e) miscarriage(s) in history.
Frozen (s) or regressing (and e) pregnancy (s) in history.
The presence of occupational hazards.
Previously diagnosed chromosomal abnormalities and (or) fetal malformations based on screening results in past pregnancies, or the presence of children born with such anomalies.
Women who have had an infectious disease in early pregnancy.
Women who took drugs that are prohibited for pregnant women in the early stages of pregnancy.
The presence of alcoholism, drug addiction.
Hereditary diseases in the family of a woman or in the family of the child's father.
I am closely related to the relationship between the mother and father of the child.

Prenatal screening at 11-13 weeks of gestation consists of two research methods - ultrasound screening of the 1st trimester and biochemical screening.

Screening Ultrasound

Preparation for the study: If the ultrasound is performed transvaginally (the probe is inserted into the vagina), then no special preparation is required. If ultrasound is performed transabdominally (the sensor is in contact with the anterior abdominal wall), then the study is performed with a full bladder. To do this, it is recommended not to urinate 3-4 hours before it, or one and a half hours before the study, drink 500-600 ml of water without gas.

Necessary conditions for obtaining reliable ultrasound data. According to the norms, screening of the first trimester in the form of ultrasound is carried out:

Not earlier than 11 obstetric weeks and not later than 13 weeks and 6 days.
KTR (coccyx-parietal size) of the fetus is not less than 45 mm.
The position of the child should allow the doctor to adequately take all measurements, otherwise, it is necessary to cough, move, walk for a while so that the fetus changes its position.

As a result of ultrasound the following indicators are studied:

KTR (coccygeal-parietal size) - measured from the parietal bone to the coccyx
Head circumference
BDP (biparietal size) - the distance between the parietal tubercles
Distance from frontal bone to occipital bone
Symmetry of the cerebral hemispheres and its structure
TVP (collar space thickness)
HR (heart rate) of the fetus
The length of the humerus, femur, as well as the bones of the forearm and lower leg
Location of the heart and stomach in the fetus
Dimensions of the heart and great vessels
The location of the placenta and its thickness
Number of waters
The number of vessels in the umbilical cord
Condition of the internal cervical os
Presence or absence of uterine hypertonicity

Decryption of the received data:

What pathologies can be detected as a result of ultrasound?

According to the results of ultrasound screening of the 1st trimester, we can talk about the absence or presence of the following anomalies:

Trisomy 21 is the most common genetic disorder. The prevalence of detection is 1:700 cases. Thanks to prenatal screening, the birth rate of children with Down syndrome has decreased to 1:1100 cases.
Neural tube pathologies(meningocele, meningomyelocele, encephalocele and others).
Omphalocele is a pathology in which part of internal organs is located under the skin of the anterior abdominal wall in the hernial sac.
Patau's syndrome is a trisomy of chromosome 13. The frequency of occurrence is on average 1:10,000 cases. 95% of children born with this syndrome die within a few months due to severe damage to the internal organs. On ultrasound - rapid fetal heart rate, impaired brain development, omphalocele, slowing down the development of tubular bones.
Trisomy 18 chromosome. The frequency of occurrence is 1:7000 cases. It is more common in children whose mothers are older than 35. On ultrasound, there is a decrease in the fetal heartbeat, an omphalocele, nasal bones are not visible, one umbilical artery instead of two.
Triploidy is a genetic anomaly in which there is a triple set of chromosomes instead of a double set. Accompanied by multiple malformations in the fetus.
Cornelia de Lange syndrome- a genetic anomaly in which the fetus has various malformations, and in the future mental retardation. The incidence rate is 1:10,000 cases.
Smith-Opitz syndrome- an autosomal recessive genetic disease, manifested by a metabolic disorder. As a result, the child has multiple pathologies, mental retardation, autism and other symptoms. The frequency of occurrence is on average 1:30,000 cases.

More about diagnosing Down syndrome

Mostly, an ultrasound scan at 11-13 weeks of gestation is performed to detect Down syndrome. The main indicator for diagnosis is:

The thickness of the collar space (TVP). TVP is the distance between soft tissues neck and skin. An increase in the thickness of the collar space may indicate not only an increased risk of having a child with Down syndrome, but also that other genetic pathologies in the fetus are possible.
In children with Down syndrome, most often for a period of 11-14 weeks, the nasal bone is not visualized. The contours of the face are smoothed.

Before 11 weeks of gestation, the thickness of the collar space is so small that it cannot be adequately and reliably assessed. After 14 weeks, the lymphatic system is formed in the fetus and this space can normally be filled with lymph, so the measurement is also not reliable. The frequency of occurrence of chromosomal abnormalities in the fetus, depending on the thickness of the collar space.

When deciphering the screening data of the 1st trimester, it should be remembered that the thickness of the collar space alone is not a guide to action and does not indicate a 100% probability of a child having a disease.

Therefore, the next stage of screening of the 1st trimester is carried out - taking blood to determine the level of β-hCG and PAPP-A. Based on the obtained indicators, the risk of chromosomal pathology is calculated. If the risk according to the results of these studies is high, then an amniocentesis is suggested. This is the taking of amniotic fluid for a more accurate diagnosis.

In particularly difficult cases, cordocentesis may be required - taking cord blood for analysis. A chorionic villus biopsy may also be used. All of these methods are invasive and carry risks for the mother and fetus. Therefore, the decision to conduct them is decided by the woman and her doctor jointly, taking into account all the risks of conducting and refusing the procedure.

Biochemical screening of the first trimester of pregnancy

This stage of the study is carried out necessarily after ultrasound. This is an important condition, because all biochemical parameters depend on the gestational age up to the day. Every day the standards change. And ultrasound allows you to determine the gestational age with the accuracy that is necessary for a proper study. At the time of blood donation, you should already have the results of an ultrasound scan with the indicated gestational age based on the KTP. Also, an ultrasound scan may reveal a frozen pregnancy, a regressing pregnancy, in which case further examination does not make sense.

Study preparation

Blood is taken on an empty stomach! It is undesirable even to drink water in the morning of this day. If the study is carried out too late, it is allowed to drink some water. It is better to take food with you and have a snack immediately after blood sampling, rather than violate this condition.

2 days before the appointed day of the study, all foods that are strong allergens should be excluded from the diet, even if you have never had an allergy to them - these are chocolate, nuts, seafood, as well as very fatty foods and smoked meats.

Otherwise, the risk of obtaining false results is significantly increased.

Consider what deviations from the normal values of β-hCG and PAPP-A may indicate.

β-hCG - human chorionic gonadotropin

This hormone is produced by the chorion (“shell” of the fetus), thanks to this hormone, it is possible to determine the presence of pregnancy in the early stages. The level of β-hCG gradually increases in the first months of pregnancy, its maximum level is observed at 11-12 weeks of pregnancy. Then the level of β-hCG gradually decreases, remaining unchanged throughout the second half of pregnancy.

Normal levels of chorionic gonadotropin, depending on the duration of pregnancy:		An increase in the level of β-hCG is observed in the following cases:	A decrease in the level of β-hCG is observed in the following cases:
weeks	β-hCG, ng/ml	Down syndrome Multiple pregnancy severe toxicosis maternal diabetes mellitus	Edwards syndrome Ectopic pregnancy (but this is usually established before the biochemical study) High risk of miscarriage
10	25,80-181,60
11	17,4-130,3
12	13,4-128,5
13	14,2-114,8

PAPP-A, pregnancy-associated protein-A

This is a protein produced by the placenta in the body of a pregnant woman, is responsible for the immune response during pregnancy, and is also responsible for the normal development and functioning of the placenta.

MoM coefficient

After receiving the results, the doctor evaluates them by calculating the MoM coefficient. This coefficient shows the deviation of the level of indicators in this woman from the average normal value. Normally, the MoM-coefficient is 0.5-2.5 (with multiple pregnancy up to 3.5).

The data of the coefficient and indicators may differ in different laboratories, the level of the hormone and protein can be calculated in other units of measurement. You should not use the data in the article as norms specifically for your study. It is necessary to interpret the results together with your doctor!

Further using computer program PRISCA, taking into account all the indicators obtained, the age of the woman, her bad habits(smoking), the presence of diabetes and other diseases, the weight of a woman, the number of fetuses or the presence of IVF - the risk of having a child with genetic abnormalities is calculated. A high risk is a risk of less than 1:380.

Example: If the conclusion indicates a high risk of 1:280, this means that out of 280 pregnant women with the same indicators, one will have a child with a genetic pathology.

Special situations where the indicators may be different.

IVF - β-hCG values will be higher, and PAPP-A - below average.
When a woman is obese, her hormone levels may increase.
In multiple pregnancies, β-hCG is higher and the norms for such cases have not yet been precisely established.
Maternal diabetes can cause hormone levels to rise.

At week 14, mom enters the second trimester of her pregnancy. This is the most pleasant and carefree time for the entire period of bearing a baby. It is not yet difficult for a woman to carry a child, but it is already possible to enjoy all the delights of her “interesting” position. Sometimes this week, the expectant mother goes to a planned ultrasound. What can be seen at such a time and how to understand the results of this study, we will describe in this article.

Survey objectives

The 14th week of pregnancy is 12 weeks from the moment of conception and approximately 10 weeks from the onset of the delay. In her pregnancy, a woman no longer doubts. It is this week that she can go for an ultrasound scan, which is part of the first prenatal screening. This screening, which is recommended for all pregnant women, usually passes from 11 to 13 weeks inclusive. Thus, at week 14, there are six days during which a woman needs to have time to undergo this important and informative examination, if she did not do this a week or two ago.

As part of the screening examination, not only the child is examined by ultrasound, but also a laboratory biochemical blood test is performed to determine the concentration of a hormone important for the course of pregnancy. hCG and plasma protein RAPP-A. All information is evaluated in a complex and allows us to judge whether a woman has an increased risk of giving birth to a child with severe genetic abnormalities.

If the screening has already been completed, then at week 14 there may be other indications for an ultrasound scan:

the threat of abortion, pain, the appearance of spotting;

poor screening results requiring a follow-up examination;

clarification of the gestational age, if the obstetrician-gynecologist has doubts, if the size of the uterus does not correspond to the specified obstetric period;

exclusion of fetal growth retardation, non-developing pregnancy.

Some pregnant women this week may go for an ultrasound without a referral from their doctor to find out the sex of the child, since it is not always possible to see the gender of the fetus during the first screening at 11-12 weeks.

Features of diagnostics and preparation

At this time, expectant mothers in the vast majority of cases are diagnosed abdominally - the scanner sensor is located on the stomach. The size of the uterus and the amount of amniotic fluid allow a good view of the baby. However, in exceptional cases, an intravaginal examination method can also be used. With it, the sensor is inserted into the vagina and the uterine cavity is examined through the thinnest wall of the uterus.

A doctor is more likely to use a vaginal probe if a woman has magnificent forms if she has fat deposits that make it difficult to see, and also if she is likely to spontaneous miscarriage, because such a condition requires a careful study of the cervix, cervical canal, and the review through the vagina will be the most reliable.

There is no need for any specific preparation for ultrasound at this time. Before a vaginal (internal) ultrasound, the doctor may ask the woman to empty her bladder. In advance, you should take care that the intestines are not filled with feces and intestinal gases - before visiting the diagnostic room, you should go to the toilet and take a dose of drugs that prevent increased flatulence - "Smektu" or "Simethicone".

You should take a diaper with you to the ultrasound room to lay it on the couch, as well as disposable medical wipes to remove the remnants of the gel from the skin, which is used during ultrasound scanning through the abdominal wall to facilitate the passage of ultrasound waves.

What can be seen?

The baby has grown up - the weight of the fetus at week 14 is already from 30 to 50 grams, the size of the fetus is 12-14 centimeters. During this period, the formation and development of the spine is in full swing, the muscular and skeletal systems are being improved. The child actively moves, waves his arms and legs, tumbles, makes swimming movements, but the woman cannot yet feel them, because there is enough space in the uterus, and the baby is not yet pushing the walls of the uterus. But somersaults and swings are clearly visible during the passage of an ultrasound examination.

This week, the baby clearly distinguishes between periods of wakefulness and sleep. However, he continues to move even in a dream, because neural connections are formed between the muscles and the brain, and therefore the movements in a dream are reflex in nature. During this period, the baby comprehends another important "science" - he learns to smile and use facial muscles.

Therefore, on an ultrasound scan performed by a scanner with high resolution- 3D, you can, if you're lucky, see the first grimaces that the baby depicts on his face.

The face itself this week also begins to undergo changes - the eyes, widely spaced on the sides, begin to draw closer, the auricles “slide” into their proper place. The kid is well oriented in sounds. He hears the sound accompaniment of his mother's body - the beating of the heart, breathing, bowel movements, and also quite emotionally responds to sounds from the outside. On ultrasound, the baby respond to unfamiliar voices of medical staff and light pressure on the mother's belly sensor. The reaction can be of two types: either the baby will perk up and begin to actively move, or “get scared” and hide. Sometimes a shy baby may begin to "run" from the sensor, trying to intuitively hide.

Many mothers are alarmed when they see on the monitor not a chubby baby, as they imagined him to be, but a thin “goal” with short legs, thin and thin arms and a still big head. This is an absolute norm, this is exactly what a child should be at this time. He will begin to accumulate subcutaneous fat closer to childbirth.

Formed external genitalia. At good review You can already see the gender of the baby. The child actively swallows the amniotic fluid in which he swims and urinates into it. The composition of the waters is updated every three hours. In general, the baby already looks completely “human”, it no longer looks like an embryo.

Deciphering the results

First of all, the number of fetuses and their position in the uterus is determined. If at this time the doctor indicates that the child is in the pelvic or transverse presentation, there is nothing wrong with this, since the baby is actively tossing and turning, and will change its position in space more than a dozen times until it grows up enough to take a single presentation.

The development of the baby at this time is indicated by the main dimensions, which are described in the conclusion under the heading - “Fetometry”. The norms for this period (13-14 weeks) are as follows:

(The table shows the minimum and maximum values of the indicator for this period).

Among the anatomical indicators, the doctor examines and evaluates the structures of the brain, a large cistern, indicates the size of the cerebellum. For 14 weeks, the normal size of the cerebellum is considered to be from 1 to 1.5 cm. The spine, heart, stomach, intestines of the baby, and his lungs are examined.

The dimensions considered important at this time are the length of the bones of the nose and the thickness of the collar space. Both of these indicators can indirectly indicate the existing pathologies of genetic origin. TVP at week 14 is normally 1.7 mm (deviations in the range of 0.8-2.7 are permissible). The bones of the nose should be determined, their size at this time is 2.0-2.9 mm.

Such a size as TVP, after 14 weeks, loses its diagnostic value, and if you go for an ultrasound a week later, at 14-15 weeks, then TVP will no longer be measured.

In addition, the doctor evaluates condition of the amniotic fluid, their number, the place of attachment of a young, newly formed placenta, counts the number of vessels in the umbilical cord. Normally there should be 3.

Possible problems

Among the most common problems that can be detected on ultrasound at this time is the discrepancy between the size of the fetus and the gestational age. If the lagging behind or ahead of the existing norms is insignificant, nothing terrible happens - the child may already show individual features of appearance (someone has a larger head, someone has a longer nose, etc.).