What does a baby look like at 12 weeks? The algorithm of action in case of poisoning is simple

Prenatal screening examination of the first trimester consists of two procedures: ultrasound diagnostics and blood testing for the possibility of genetic pathologies of the fetus. There is nothing wrong with these events. The data obtained through an ultrasound procedure and a blood test are compared with the norm for this period, which makes it possible to confirm the good or identify the poor condition of the fetus and determine the quality of the gestation process.

For the expectant mother, the main task is to maintain good psycho-emotional and physical condition. It is also important to follow the instructions of the obstetrician-gynecologist leading the pregnancy.

Standards for ultrasound diagnostics I screening

During the first prenatal screening in 1st trimester The ultrasound diagnostic doctor pays special attention to the anatomical structures of the fetus, clarifies the gestational age (gestation) based on fetometric indicators, comparing with the norm. The most carefully assessed criterion is the thickness of the collar space (TVP), because This is one of the main diagnostically significant parameters, which makes it possible to identify genetic diseases of the fetus during the first ultrasound procedure. With chromosomal abnormalities, the nuchal space is usually expanded. Weekly TVP norms are given in the table:

When performing ultrasound screening in the first trimester, the doctor pays special attention to the structure of the facial structures of the fetal skull, the presence and parameters of the nasal bone. At 10 weeks it is already quite clearly defined. At 12 weeks, its size in 98% of healthy fetuses ranges from 2 to 3 mm. The size of the baby’s maxillary bone is assessed and compared with the norm, because a noticeable decrease in jaw parameters in relation to the norm indicates trisomy.

During the 1st screening ultrasound, the fetal heart rate (heart rate) is recorded and also compared with the norm. The indicator depends on the stage of pregnancy. Weekly heart rate norms are shown in the table:

The main fetometric indicators at this stage during the ultrasound procedure are the coccygeal-parietal (CP) and biparietal (BPR) dimensions. Their norms are given in the table:

The first screening involves an ultrasound assessment of blood flow in the ductus venosus (Arantius), since in 80% of cases of its violation the child is diagnosed with Down syndrome. And only in 5% of genetically normal fetuses such changes are detected.

Starting from the 11th week, it becomes possible to visually recognize the bladder during ultrasound. At the 12th week, during the first ultrasound screening, its volume is assessed, since an increase in the size of the bladder is another evidence of the threat of developing trisomy (Down) syndrome.

It is best to donate blood for biochemistry on the same day as the ultrasound screening. Although this is not a mandatory requirement. Blood is drawn on an empty stomach. Analysis of biochemical parameters, which is carried out in the first trimester, is aimed at identifying the degree of threat of genetic diseases in the fetus. For this purpose, the following hormones and proteins are determined:

• pregnancy-associated plasma protein-A (PAPP-A);
• free hCG (beta component).

These indicators depend on the week of pregnancy. The range of possible values ​​is quite wide and correlates with the ethnic content of the region. In relation to the average normal value for a given region, the level of indicators fluctuates within the following limits: 0.5-2.2 MoM. When calculating the threat and deciphering the data for analysis, not just the average value is taken, all possible corrections for the anamnestic data of the expectant mother are taken into account. Such an adjusted MoM makes it possible to more fully determine the threat of developing genetic pathology in the fetus.

HCG: risk assessment

In terms of information content, free hCG (beta component) is superior to total hCG as a marker of the risk of fetal genetic abnormalities. The beta-hCG norms for a favorable course of gestation are shown in the table:

This biochemical indicator is one of the most informative. This applies to both identifying genetic pathology and marking the course of the gestation process and changes occurring in the body of a pregnant woman.

Standards for pregnancy-associated plasma protein-A

This is a specific protein that the placenta produces throughout the gestational period. Its growth corresponds to the period of pregnancy development and has its own standards for each period. If there is a decrease in the level of PAPP-A in relation to the norm, this is reason to suspect the threat of developing a chromosomal abnormality in the fetus (Down and Edwards disease). The norms for PAPP-A indicators during normal gestation are shown in the table:

However, the level of protein associated with pregnancy loses its informative value after the 14th week (as a marker of the development of Down's disease), since after this period its level in the blood of a pregnant woman carrying a fetus with a chromosomal abnormality corresponds to the normal level - as in the blood of a woman with healthy pregnancy.

Description of the first trimester screening results

To evaluate the results of screening I, each laboratory uses a specialized computer product - certified programs that are configured for each laboratory separately. They make a basic and individual calculation of the threat indicators for the birth of a baby with a chromosomal abnormality. Based on this information, it becomes clear that it is better to carry out all tests in one laboratory.

The most reliable prognostic data are obtained by undergoing the first prenatal screening in the first trimester in full (biochemistry and ultrasound). When deciphering data, both indicators of biochemical analysis are considered in combination:

low values ​​of protein-A (PAPP-A) and elevated beta-hCG – a risk of developing Down syndrome in a child;
low performance Protein A and low beta-hCG are a threat to Edwards disease in a baby.
There is a fairly accurate procedure to confirm a genetic abnormality. However, this is an invasive test that can be dangerous for both mother and baby. To clarify the need to use this technique, ultrasound diagnostic data are analyzed. If there are echo signs of a genetic abnormality on an ultrasound scan, the woman is recommended to undergo invasive diagnostics. In the absence of ultrasound data indicating the presence of a chromosomal pathology, the expectant mother is recommended to repeat the biochemistry (if the period has not reached 14 weeks), or wait for the indications of the 2nd screening study in the next trimester.

Risk assessment

The information received is processed by a program specially created to solve this problem, which calculates the risks and gives a fairly accurate forecast regarding the threat of developing chromosomal abnormalities of the fetus (low, threshold, high). It is important to remember that the resulting transcript of the results is only a forecast, not a final verdict.

Quantitative expressions of levels vary in each country. For us, a value of less than 1:100 is considered a high level. This ratio means that for every 100 births (with similar test results), 1 child is born with a genetic pathology. This degree of threat is considered an absolute indication for invasive diagnostics. In our country, the threshold level is considered to be the risk of having a baby with developmental defects in the range from 1:350 to 1:100.

The threshold level of threat means that the child may be born sick with a risk of 1:350 to 1:100. At a threshold level of threat, the woman is sent to see a geneticist, who gives a comprehensive assessment of the data obtained. The doctor, having studied the parameters and medical history of the pregnant woman, identifies her in the risk group (with a high or low degree). Most often, the doctor recommends waiting until the second trimester screening test is performed, and then, having received a new threat calculation, come back for an appointment to clarify the need for invasive procedures.

The information described above should not frighten expectant mothers, and there is also no need to refuse to undergo first trimester screening. Since most pregnant women have no high risk carry a sick baby, they do not require additional invasive diagnostics. Even if the examination showed poor condition fetus, it is better to find out about it in a timely manner and take appropriate measures.

If unfavorable results are obtained, what to do?

If it so happens that the analysis of the screening examination indicators of the first trimester revealed high degree threats of the birth of a child with a genetic anomaly, first of all, you need to pull yourself together, since emotions negatively affect the gestation of the fetus. Then start planning your next steps.

First of all, it is unlikely to be worth the time and money to undergo re-screening at another laboratory. If the risk analysis shows a ratio of 1:100, you cannot hesitate. You should immediately contact a geneticist for advice. The less time is lost, the better. With such indicators, a traumatic method of confirming the data will most likely be prescribed. At 13 weeks, this will be an analysis of chorionic villus biopsy. After 13 weeks, it may be recommended to perform a cordo- or amniocentesis. Analysis of chorionic villus biopsy provides the most accurate results. The waiting period for results is about 3 weeks.

If the development of chromosomal abnormalities of the fetus is confirmed, the woman will be recommended to have an artificial termination of pregnancy. The decision is, of course, up to her. But if the decision is made to terminate the pregnancy, then the procedure is best performed at 14-16 weeks.

Some time ago, pregnant women did not even know about such a procedure as prenatal or perinatal . Now all expectant mothers undergo such examination.

What is screening during pregnancy, why is it performed and why are its results so important? Answers to these and other questions that concern many pregnant women about perinatal screening We tried to give in this material.

In order to eliminate any further misunderstanding of the information presented, before moving directly to the consideration of the above topics, it is worth defining some medical terms.

Prenatal screening is a special variation of what is actually a standard procedure, such as screening. Given a comprehensive examination consists of Ultrasound diagnostics and laboratory research, in this particular case biochemistry of maternal serum. Identification on early stage some genetic abnormalities - That's what it is the main task analysis during pregnancy such as screening.

Prenatal or perinatal means prenatal, and by the term screening in medicine, we mean a series of studies of a large segment of the population, which are carried out in order to form a so-called “risk group” susceptible to certain diseases.

Can be universal or selective screening .

It means that screening studies done not only to pregnant women, but also to other categories of people, for example, children of the same age to establish characteristic of this period life of diseases.

With help genetic screening Doctors can find out not only about problems in the baby’s development, but also react in time to complications during pregnancy, which a woman may not even suspect.

Often, expectant mothers, having heard that they will have to undergo this procedure several times, begin to panic and worry in advance. However, there is nothing to be afraid of, you just need to ask your gynecologist in advance why you need screening for pregnant women, when and, most importantly, how this procedure is done.

So, let's start with what is standard screening carried out three times during the entire pregnancy, i.e. in every trimester . Let us remind you that trimester is a period of three months.

What it is 1st trimester screening ? First, let's answer a common question about how many weeks it is. first trimester of pregnancy . In gynecology, there are only two ways to reliably determine the due date during pregnancy - calendar and obstetric.

The first is based on the day of conception, and the second depends on menstrual cycle , preceding fertilization . That's why I trimester - this is the period that, according to the calendar method, begins with the first week from conception and ends with the fourteenth week.

According to the second method, I trimester – this is 12 obstetric weeks. Moreover, in this case, the period is counted from the beginning of the last menstruation. Recently screening not prescribed to pregnant women.

However, now many expectant mothers themselves are interested in undergoing such an examination.

In addition, the Ministry of Health strongly recommends that studies be prescribed to all expectant mothers without exception.

True, this is done voluntarily, because no one can force a woman to undergo any kind of analysis.

It is worth noting that there are categories of women who are simply obliged, for one reason or another, to undergo screening, For example:

• pregnant women from thirty-five years of age and beyond;
• expectant mothers whose medical history contains information about the presence of a threat spontaneous ;
• women who in the first trimester had infectious diseases ;
• pregnant women who are forced for health reasons to take medications prohibited for their situation in the early stages;
• women who have had various genetic abnormalities or abnormalities in fetal development ;
• women who have previously given birth to children with any deviations or developmental defects ;
• women who have been diagnosed frozen or regressing pregnancy (cessation of fetal development);
• suffering from narcotic or women;
• pregnant women in whose family or in the family of the father of the unborn child there have been cases of hereditary genetic disorders .

How long does it take to do it? prenatal screening 1st trimester ? For the first screening during pregnancy, the period is set in the interval from 11 weeks to 13 obstetric weeks of pregnancy and 6 days. There is no point in conducting this examination earlier than the specified period, since its results will be uninformative and absolutely useless.

It is no coincidence that a woman’s first ultrasound is performed at 12 weeks of pregnancy. Since this is when it ends embryonic and it begins fetal or fetal period of development of the future person.

This means that the embryo turns into a fetus, i.e. obvious changes occur that indicate the development of a full-fledged living human organism. As we said earlier, screening studies is a set of measures that consists of ultrasound diagnostics and biochemistry of a woman’s blood.

It is important to understand that conducting screening ultrasound in the 1st trimester during pregnancy plays the same important role as laboratory blood tests. Indeed, in order for geneticists to draw the correct conclusions based on the results of the examination, they need to study both the ultrasound results and the biochemistry of the patient’s blood.

How many weeks is the first screening carried out? We talked, now let’s move on to deciphering the results comprehensive research. It is really important to take a closer look at the standards established by doctors for the results of the first screening during pregnancy. Of course, only a specialist in this field with the necessary knowledge and, most importantly, experience can give a qualified assessment of the results of the analysis.

We believe that it is advisable for any pregnant woman to know at least general information about the main indicators prenatal screening and their normative values. After all, it is typical for most expectant mothers to be overly suspicious about everything that concerns the health of their future child. Therefore, they will be much more comfortable if they know in advance what to expect from the study.

Interpretation of 1st trimester ultrasound screening, norms and possible deviations

All women know that during pregnancy they will have to undergo more than one ultrasound examination (hereinafter referred to as ultrasound), which helps the doctor monitor the intrauterine development of the unborn child. In order to screening ultrasound gave reliable results, you need to prepare in advance for this procedure.

We are sure that the vast majority of pregnant women know how to do this procedure. However, it is worth repeating that there are two types of research - transvaginal and transabdominal . In the first case, the device sensor is inserted directly into the vagina, and in the second it is in contact with the surface of the anterior abdominal wall.

There are no special preparation rules for transvaginal ultrasound.

If you are undergoing a transabdominal examination, then before the procedure (about 4 hours before the ultrasound) you should not go to the toilet “small”, and it is recommended to drink up to 600 ml of plain water half an hour before.

The thing is that the examination must be carried out on fluid-filled bladder .

In order for the doctor to obtain a reliable result Ultrasound screening, The following conditions must be met:

• the examination period is from 11 to 13 obstetric weeks;
• the position of the fetus should allow the specialist to carry out the necessary manipulations, otherwise the mother will have to “influence” the baby so that he turns over;
• coccyx-parietal size (hereinafter KTR) should not be less than 45 mm.

What is CTE during pregnancy on ultrasound

When performing an ultrasound, a specialist must examine various parameters or fetal size. This information allows you to determine how well the baby is formed and whether he is developing correctly. The norms for these indicators depend on the stage of pregnancy.

If the value of one or another parameter obtained as a result of ultrasound deviates from the norm upward or downward, then this is considered a signal of the presence of some pathologies. Coccyx-parietal size - This is one of the most important initial indicators of proper intrauterine development of the fetus.

The CTE value is compared with the weight of the fetus and the gestational age. This indicator is determined by measuring the distance from the child’s crown bone to his tailbone. As a general rule, the higher the CTE index, the longer the gestational age.

When this indicator is slightly higher or, conversely, slightly lower than the norm, then there is no reason to panic. This only speaks about the developmental characteristics of this particular child.

If the CTE value deviates upward from the standards, then this signals the development of a large-sized fetus, i.e. Presumably, the baby’s weight at birth will exceed the average norm of 3-3.5 kg. In cases where the CTE is significantly less than the standard values, this may be a sign that:

• pregnancy does not develop as expected, in such cases the doctor should carefully check the fetal heartbeat. If he died in the womb, then the woman needs urgent medical attention ( scraping uterine cavity ) to prevent possible health hazards ( development of infertility ) and life ( infection, bleeding );
• The pregnant woman's body produces an insufficient amount, as a rule, which can lead to spontaneous miscarriage. In such cases, the doctor prescribes an additional examination for the patient and prescribes medications containing hormones ( , Dufston );
• mother is sick infectious diseases , including sexually transmitted diseases;
• the fetus has genetic abnormalities. In such situations, doctors prescribe additional tests along with, which is part of the first screening test.

It is also worth emphasizing that there are often cases when a low CTE indicates an incorrectly determined gestational age. This refers to the normal variant. All a woman needs in such a situation is to undergo a second ultrasound examination after some time (usually after 7-10 days).

Fetal BDP (biparietal size)

What is BPD on ultrasound during pregnancy? When conducting an ultrasound examination of the fetus in the first trimester, doctors are interested in all possible characteristics of the unborn child. Since their study gives specialists maximum information about how the intrauterine development of a little man occurs and whether everything is in order with his health.

What is it Fetal BD ? First, let's decipher the medical abbreviation. BPR - This biparietal fetal head size , i.e. distance between walls parietal bones of the skull , simply the size of the head. This indicator is considered one of the main ones for determining the normal development of a child.

It is important to note that the BDP shows not only how well and correctly the baby is developing, but also helps doctors prepare for the upcoming birth. Because if the size of the unborn child’s head deviates from the norm upward, then it simply will not be able to pass through the mother’s birth canal. In such cases, a planned caesarean section is prescribed.

When the BPR deviates from established standards, this may indicate:

• about the presence of pathologies incompatible with life in the fetus, such as cerebral hernia or tumor ;
• about the fairly large size of the unborn child, if other basic parameters of the fetus are several weeks ahead of the established development standards;
• about spasmodic development, which will return to normal after some time, provided that other basic parameters of the fetus fit into the norm;
• about fetal development brain resulting from the presence of infectious diseases in the mother.

A downward deviation of this indicator indicates that the baby’s brain is not developing properly.

Neck thickness (TCT)

Fetal TVP - what it is? Collar space in the fetus or size neck fold - this is a place (more precisely, an oblong formation) located between the neck and the upper skin membrane of the baby’s body, in which there is an accumulation of fluid. A study of this value is carried out during screening in the first trimester of pregnancy, since it is during this period that it is possible to measure TVP for the first time and then analyze it.

Starting from the 14th week of pregnancy, this formation gradually decreases in size and by the 16th week it practically disappears from visibility. Certain standards have also been established for TVP, which are directly dependent on the duration of pregnancy.

For example, the norm collar space thickness at 12 weeks should not go beyond the range of 0.8 to 2.2 mm. Collar thickness at 13 weeks it should be between 0.7 and 2.5 mm.

It is important to note that for this indicator, experts establish average minimum values, deviation from which indicates a thinning of the collar space, which, like the expansion of the TVP, is considered an anomaly.

If this indicator does not correspond to the TVP norms indicated in the table above at 12 weeks and at other stages of pregnancy, then this result most likely indicates the presence of the following chromosomal abnormalities:

• trisomy 13 , a disease known as Patau syndrome, characterized by the presence in human cells of an additional 13th chromosome;
• trisomy 21 chromosome, known to everyone as Down syndrome , a human genetic disease in which karyotype (i.e. a complete set of chromosomes) is represented by 47 chromosomes instead of 46;
• monosomy on the X chromosome , a genomic disease named after the scientists who discovered it Shereshevsky-Turner syndrome, it is characterized by such anomalies of physical development as short stature, as well as sexual infantilism (immaturity);
• trisomy 18 is a chromosomal disease. For Edwards syndrome (the second name of this disease) is characterized by a multiplicity of developmental defects incompatible with life.

Trisomy - this is an option aneuploidy , i.e. changes karyotype , in which there is an additional third in the human cell chromosome instead of normal diploid set.

Monosomy - this is an option aneuploidy (chromosomal abnormality) , in which there are no chromosomes in the chromosome set.

What are the standards for trisomy 13, 18, 21 installed during pregnancy? It happens that during the process of cell division there is a failure. This phenomenon is called in science aneuploidy. Trisomy - This is one of the types of aneuploidy, in which instead of a pair of chromosomes, an extra third chromosome is present in the cell.

In other words, the child inherits from his parents an additional 13, 18 or 21 chromosome, which in turn entails genetic abnormalities that prevent normal physical and mental development. Down syndrome According to statistics, this is the most common disease caused by the presence of chromosome 21.

Children born with Edwards syndromes, the same as in the case with Patau syndrome , usually do not live to see a year, unlike those unlucky enough to be born with Down syndrome . Such people can live to a ripe old age. However, such a life can rather be called existence, especially in the countries of the post-Soviet space, where these people are considered outcasts and they try to avoid and not notice them.

In order to exclude such anomalies, pregnant women, especially those at risk, must undergo a screening examination. Researchers claim that the development of genetic abnormalities is directly dependent on the age of the expectant mother. How younger woman, the less likely it is that her baby will have any abnormalities.

To establish trisomy in the first trimester of pregnancy, a study is carried out fetal nuchal space using ultrasound. In the future, pregnant women periodically take blood tests, in which the most important indicators for geneticists are the level alpha-fetoprotein (AFP), inhibin-A, human chorionic gonadotropin (hCG) and estriol .

As mentioned earlier, the risk of a child having genetic disorders depends primarily on the age of the mother. However, there are cases when trisomy is also detected in young women. Therefore, during screening, doctors study all possible signs of abnormalities. It is believed that an experienced ultrasound specialist can identify problems during the first screening examination.

Signs of Down syndrome, as well as Edwards and Patau syndromes

Trisomy 13 is characterized by a sharp decrease in the level PAPP-A , associated with pregnancy protein (protein) A-plasma ). Also a marker of this genetic deviation is. The same parameters play an important role in determining whether the fetus has Edwards syndrome .

When there is no risk of trisomy 18, normal indicators PAPP-A and b-hCG (free hCG beta subunit) are recorded in a biochemical blood test. If these values ​​deviate from the standards established for each specific stage of pregnancy, then, most likely, the child will have genetic malformations.

It is important to note that in the case when, during the first screening, a specialist records signs indicating a risk trisomy , the woman is referred for further examination and consultation with geneticists. To make a final diagnosis, the expectant mother will have to undergo procedures such as:

• chorionic villus biopsy , i.e. obtaining a sample of chorionic tissue to diagnose anomalies;
• amniocentesis- This amniotic puncture to receive a sample amniotic fluid for the purpose of their further study in the laboratory;
• placentocentesis (biopsy of the placenta) , given invasive diagnostic method specialists select a sample placental tissue using a special puncture needle, which pierces anterior abdominal wall ;
• cordocentesis , a method for diagnosing genetic abnormalities during pregnancy, in which the umbilical cord blood of the fetus is analyzed.

Unfortunately, if a pregnant woman has undergone any of the above studies and is diagnosed with bioscreening and ultrasound the diagnosis of the presence of genetic abnormalities in the fetus has been confirmed, doctors will suggest terminating the pregnancy. In addition, in contrast to standard screening studies, the data invasive examination methods can provoke a number of serious complications, including spontaneous miscarriage, so doctors resort to them in a fairly rare number of cases.

Nasal bone - This is a slightly elongated, quadrangular, convex front paired bone of the human face. During the first ultrasound screening, the specialist determines the length of the baby’s nasal bone. It is believed that in the presence of genetic abnormalities, this bone develops incorrectly, i.e. its ossification occurs later.

Therefore, if the nasal bone is missing or its size is too small during the first screening, this indicates the possible presence of various anomalies. It is important to emphasize that the length of the nasal bone is measured at 13 weeks or 12 weeks. When screening at 11 weeks, the specialist only checks for its presence.

It is worth emphasizing that if the size of the nasal bone does not correspond to the established standards, but other basic indicators comply, there is really no reason for concern. This state of affairs may be due to the individual developmental characteristics of this particular child.

Heart rate (HR)

A parameter like Heart rate plays an important role not only in the early stages, but throughout pregnancy. Constantly measure and monitor fetal heart rate It is necessary only in order to notice deviations in time and, if necessary, save the baby’s life.

The interesting thing is that although myocardium (heart muscle) begins to contract already in the third week after conception, you can hear the heartbeat only starting from the sixth obstetric week. It is believed that at the initial stage of fetal development, the rhythm of its heartbeat should correspond to the mother’s pulse (on average, 83 beats per minute).

However, already in the first month of intrauterine life, the baby’s heart rate will gradually increase (by about 3 beats per minute every day) and by the ninth week of pregnancy will reach 175 beats per minute. The fetal heart rate is determined using ultrasound.

When performing the first ultrasound, specialists pay attention not only to the heart rate, but also look at how the baby’s heart develops. For this they use the so-called four-chamber slice , i.e. method of instrumental diagnosis of cardiac malformations.

It is important to emphasize that a deviation from the standards of such an indicator as heart rate indicates the presence of defects in the development of the heart . Therefore, doctors carefully study the structure of the section atria And fetal heart ventricles . If any abnormalities are detected, specialists refer the pregnant woman for additional studies, for example, echocardiography (ECG) with Dopplerography.

Starting from the twentieth week, the gynecologist at the antenatal clinic will listen to the baby’s heart using a special tube at each scheduled visit to the pregnant woman. A procedure like auscultation of the heart is not used at earlier stages due to its ineffectiveness, because The doctor simply cannot hear the heartbeat.

However, as the baby develops, his heart will be heard more and more clearly each time. Auscultation helps the gynecologist determine the position of the fetus in the womb. For example, if the heart is better heard at the level of the mother’s navel, then the child is in a transverse position; if to the left of the navel or below, then the fetus is in cephalic presentation , and if above the navel, then in pelvic .

From 32 weeks of pregnancy, it is used to control the heartbeat. cardiotocography (abbreviated KTR ). When conducting the above types of examinations, a specialist can record in the fetus:

• bradycardia , i.e. abnormally low heart rate , which is usually temporary. This deviation may be a symptom of the mother having autoimmune diseases, anemia, , as well as clamping the umbilical cord when the unborn child does not receive enough oxygen. Bradycardia can also be caused by congenital heart defects In order to exclude or confirm this diagnosis, the woman must be sent for additional examinations;
• , i.e. high heart rate. Experts rarely record such a deviation. However, if the heart rate is much higher than prescribed by the standards, then this indicates that the mother or hypoxia , development intrauterine infections, anemia and genetic abnormalities in the fetus. In addition, the medications a woman takes can affect heart rate.

In addition to the characteristics discussed above, when conducting the first screening ultrasound examination, specialists also analyze the data:

• about symmetry cerebral hemispheres fetus;
• about the size of his head circumference;
• about the distance from the occipital to the frontal bone;
• about the length of the bones of the shoulders, hips and forearms;
• about the structure of the heart;
• about the location and thickness of the chorion (placenta or “baby place”);
• about the amount of water (amniotic fluid);
• about the condition of the pharynx cervix mothers;
• about the number of vessels in the umbilical cord;
• about the absence or presence hypertonicity of the uterus .

As a result of ultrasound, in addition to the genetic abnormalities already discussed above ( monosomy or Shereshevsky-Turner syndrome, trisomy of 13, 18 and 21 chromosomes , namely Down, Patau and Edwards syndromes ) the following developmental pathologies can be identified:

• neural tube , For example, spinal malformation (meningomyelocele and meningocele) or cranial hernia (encephalocele) ;
• Corne de Lange syndrome , an anomaly in which multiple developmental defects are recorded, entailing both physical abnormalities and mental retardation;
• triploidy , a genetic malformation in which a malfunction occurs in the chromosome set; as a rule, the fetus in the presence of such a pathology does not survive;
• omphalocele , embryonic or umbilical hernia, pathology of the anterior abdominal wall, in which some organs (liver, intestines and others) develop in the hernial sac outside the abdominal cavity;
• Smith-Opitz syndrome , a genetic disorder that affects processes that subsequently lead to the development of many severe pathologies, for example, or mental retardation.

Biochemical screening 1st trimester

Let's talk in more detail about the second stage of a comprehensive screening examination of pregnant women. What it is biochemical screening 1st trimester, and what standards are established for its main indicators? In fact, biochemical screening - this is nothing more than biochemical analysis blood of the expectant mother.

This study is carried out only after an ultrasound. This is due to the fact that, thanks to an ultrasound examination, the doctor determines the exact duration of pregnancy, on which the normative values ​​of the main indicators of blood biochemistry directly depend. So, remember that you need to go for biochemical screening only with the results of the ultrasound.

How to prepare for your first pregnancy screening

We talked above about how they do, and most importantly, when they do, a screening ultrasound; now it’s worth paying attention to preparing for the biochemical analysis. As with any other blood test, you need to prepare for this study in advance.

If you want to get a reliable result of biochemical screening, you will have to strictly follow the following recommendations:

• blood for biochemical screening is donated strictly on an empty stomach; doctors do not even recommend drinking plain water, not to mention any food;
• a few days before screening, you should change your usual diet and start following a gentle diet, in which you should not eat too fatty and spicy foods (so as not to increase the level), as well as seafood, nuts, chocolate, citrus fruits and other allergenic foods, even if you have not previously had an allergic reaction to anything.

Strict adherence to these recommendations will allow you to obtain reliable results of biochemical screening. Believe me, it is better to be patient for a while and give up your favorite treats, so as not to worry about the results of the analysis later. After all, doctors will interpret any deviation from established norms as a pathology in the baby’s development.

Quite often, on various forums dedicated to pregnancy and childbirth, women talk about how the results of the first screening, expected with such excitement, turned out to be bad, and they were forced to do all the procedures again. Fortunately, in the end, pregnant women received good news about the health of their babies, since the adjusted results indicated the absence of any developmental abnormalities.

The whole point was that the expectant mothers were not properly prepared for the screening, which ultimately led to the receipt of unreliable data.

Imagine how many nerves were spent and bitter tears shed while the women waited for new examination results.

Such colossal stress does not leave its mark on the health of any person, especially for a pregnant woman.

Biochemical screening 1st trimester, interpretation of results

When conducting the first biochemical screening analysis main role In diagnosing any abnormalities in fetal development, indicators such as free β-subunit of human chorionic gonadotropin (Further hCG ), and PAPP-A (pregnancy-associated plasma protein A) . Let's look at each of them in detail.

PAPP-A - what is it?

As mentioned above, PAPP-A is an indicator of a biochemical analysis of a pregnant woman’s blood, which helps specialists establish at an early stage the presence of genetic pathologies of fetal development. The full name of this quantity sounds like pregnancy associated plasma protein A , which literally translated into Russian means – pregnancy-associated plasma protein A .

It is protein A, produced by the placenta during pregnancy, that is responsible for harmonious development future child. Therefore, an indicator such as the level of PAPP-A, calculated at 12 or 13 weeks of pregnancy, is considered a characteristic marker for determining genetic abnormalities.

It is mandatory to undergo a test to check your PAPP-A level:

• pregnant women over 35 years of age;
• women who have previously given birth to children with genetic developmental disorders;
• future mothers whose family has relatives with genetic developmental disorders;
• women who have suffered diseases such as , or shortly before pregnancy;
• pregnant women who have had complications or spontaneous miscarriages before.

Standard values ​​of such an indicator as PAPP-A depend on the stage of pregnancy. For example, the PAPP-A norm at 12 weeks is from 0.79 to 4.76 mU/ml, and at 13 weeks – from 1.03 to 6.01 mU/ml. In cases where, as a result of the test, this indicator deviates from the norm, the doctor prescribes additional studies.

If the analysis reveals low level PAPP-A, then this may indicate the presence chromosomal abnormalities in child development, for example, Down syndrome, Also this signals the risk of spontaneous miscarriage and regressing pregnancy . When this indicator is elevated, this is most likely the result of the fact that the doctor was unable to correctly calculate the gestational age.

That is why blood biochemistry is donated only after an ultrasound. However, high PAPP-A may also indicate the likelihood of developing genetic abnormalities in fetal development. Therefore, if there is any deviation from the norm, the doctor will refer the woman for additional examination.

It is no coincidence that scientists gave this name to this hormone, since it is thanks to it that one can reliably find out about pregnancy already 6-8 days after fertilization has occurred eggs. It is noteworthy that hCG begins to develop chorion already in the first hours of pregnancy.

Moreover, its level is growing rapidly and by the 11-12th week of pregnancy exceeds the initial values ​​by thousands of times. Then gradually loses ground, and its indicators remain unchanged (starting from the second trimester) until childbirth. All test strips that help determine pregnancy contain hCG.

If the level human chorionic gonadotropin elevated, this may indicate:

• about the presence of the fetus Down syndrome ;
• O multiple pregnancy ;
• about the development of the mother;

When the hCG level is below the prescribed standards, it says:

• about the possible Edwards syndrome in the fetus;
• about risk miscarriage ;
• O placental insufficiency .

After a pregnant woman has undergone an ultrasound and blood biochemistry, the specialist must decipher the results of the examination, as well as calculate the possible risks of developing genetic abnormalities or other pathologies using a special computer program PRISCA (Prisca).

The screening summary form will contain the following information:

• about age-related risk developmental anomalies (depending on the age of the pregnant woman, possible deviations vary);
• about the values ​​of biochemical indicators of a woman’s blood test;
• about the risk of possible diseases;
• MoM coefficient .

In order to calculate as reliably as possible the possible risks of developing certain abnormalities in the fetus, experts calculate the so-called MoM (multiple of median) coefficient. To do this, all obtained screening data are entered into a program that builds a graph of the deviation of each indicator of the analysis of a particular woman from the average norm established for the majority of pregnant women.

A MoM that does not exceed the range of values ​​from 0.5 to 2.5 is considered normal. At the second stage, this coefficient is adjusted taking into account age, race, presence of diseases (for example, diabetes ), bad habits(for example, smoking), number of previous pregnancies, ECO and other important factors.

At the final stage, the specialist makes a final conclusion. Remember, only a doctor can correctly interpret the screening results. In the video below, the doctor explains everything key points associated with the first screening.

Cost of 1st trimester screening

The question of how much this study costs and where it is best to undergo it worries many women. The thing is that not every state clinic can do such a specific examination for free. Based on the reviews left on the forums, many expectant mothers do not trust free medicine at all.

Therefore, you can often come across the question of where to do screening in Moscow or other cities. If we talk about private institutions, then in the fairly well-known and well-established INVITRO laboratory, biochemical screening can be done for 1,600 rubles.

However, this price does not include an ultrasound scan, which the specialist will definitely ask you to present before conducting a biochemical analysis. Therefore, you will have to undergo a separate ultrasound examination in another place, and then go to the laboratory to donate blood. Moreover, this must be done on the same day.

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

Based on recommendations World Organization Health Authority (hereinafter referred to as WHO), every woman is required to undergo three screenings throughout the entire pregnancy. Although nowadays gynecologists refer all pregnant women for this examination, there are those who, for some reason, skip screening.

However, for some categories of women such research should be mandatory. This applies primarily to those who have previously given birth to children with genetic abnormalities or developmental defects. In addition, it is mandatory to undergo screening:

• women over the age of 35, since the risk of developing various pathologies in the fetus depends on the age of the mother;
• women who took medications or other prohibited drugs for pregnant women in the first trimester;
• women who have previously suffered two or more miscarriages;
• women who suffer from one of the following diseases that are inherited by the child – diabetes mellitus, diseases of the musculoskeletal system and cardiovascular system, and oncopathology;
• women who are at risk of spontaneous miscarriage.

In addition, expectant mothers should definitely undergo screening if they or their spouses were exposed to radiation before conception, or immediately before or during pregnancy bacterial and infectious diseases . As with the first screening, the second time the expectant mother must also do an ultrasound and take a biochemical blood test, which is often called a triple test.

Timing of the second screening during pregnancy

So, let’s answer the question about how many weeks the second one is done screening during pregnancy. As we have already determined, the first study is carried out in the early stages of pregnancy, namely in the period from 11 to 13 weeks of the first trimester. The next screening study is carried out during the so-called “golden” period of pregnancy, i.e. in the second trimester, which begins at 14 weeks and ends at 27 weeks.

The second trimester is called the golden one, because it is during this period of time that all the initial ailments associated with pregnancy ( nausea, weakness, and others) recede, and the woman can fully enjoy her new state, as she feels a powerful surge of strength.

A woman should visit her gynecologist every two weeks so that she can monitor the progress of her pregnancy.

The doctor gives the expectant mother recommendations regarding her interesting situation, and also informs the woman about what examinations and when she should undergo them. Typically, a pregnant woman undergoes a urine test and a general blood test before each visit to the gynecologist, and the second screening takes place from the 16th to the 20th week of pregnancy.

Ultrasound screening 2nd trimester - what is it?

When conducting the second screening First they undergo an ultrasound to determine exact date pregnancy, so that later specialists can correctly interpret the results of a biochemical blood test. On Ultrasound the doctor studies the development and size of the internal organs of the fetus: length of bones, volume chest, head and abdomen, development of the cerebellum, lungs, brain, spine, heart, bladder, intestines, stomach, eyes, nose, as well as symmetry of the facial structure.

In general, everything that is visualized using ultrasound examination is analyzed. In addition to studying the basic characteristics of the baby’s development, experts check:

• how the placenta is located;
• thickness of the placenta and its degree of maturity;
• number of vessels in the umbilical cord;
• condition of the walls, appendages and cervix;
• quantity and quality of amniotic fluid.

Standards for ultrasound screening in the 2nd trimester of pregnancy:

Decoding the triple test (biochemical blood test)

In the second trimester, experts pay special attention to three markers of genetic abnormalities such as:

• human chorionic gonadotropin – this is produced by the fetal chorion;
• alpha-fetoprotein ( Further AFP ) - This plasma protein (protein), originally produced yellow body and then produced liver and gastrointestinal tract of the fetus ;
• free estriol ( next hormone E3 ) is a hormone produced in placenta , and fetal liver.

In some cases, the level is also studied inhibin (hormone, produced follicles) . For each week of pregnancy, certain standards are established. It is considered optimal to conduct a triple test at 17 weeks of pregnancy.

When the hCG level is too high during the second screening, this may indicate:

• about multiple births pregnancy ;
• O diabetes mellitus at the mother's;
• about the risk of developing Down syndrome , if two other indicators are below normal.

If hCG, on the contrary, is lowered, then this says:

• about risk Edwards syndrome ;
• O frozen pregnancy;
• O placental insufficiency .

When AFP levels are high, there is a risk of:

• presence of developmental anomalies kidney ;
• defects neural tube ;
• developmental disabilities abdominal wall ;
• damage brain ;
• oligohydramnios ;
• fetal death;
• spontaneous miscarriage;
• emergence Rhesus conflict .

Reduced AFP may be a signal:

• Edwards syndrome ;
• diabetes mellitus mothers;
• low position placenta .

At a low level there is a high risk:

• development anemia in the fetus;
• adrenal and placental insufficiency;
• spontaneous miscarriage ;
• availability Down syndrome ;
• development intrauterine infection ;
• delayed physical development of the fetus.

It is worth noting that at the level hormone E3 Some medications (for example,), as well as improper and unbalanced nutrition of the mother, have an effect. When E3 is elevated, doctors diagnose diseases kidney or multiple pregnancies, and also predict premature birth when estriol levels rise sharply.

After the expectant mother undergoes two stages of screening, doctors analyze the information received using a special computer program and calculate the same MoM coefficient , as in the first study. The conclusion will indicate the risks for this or that type of deviation.

Values ​​are reported as a fraction, for example 1:1500 (i.e. one in 1500 pregnancies). It is considered normal if the risk is less than 1:380. Then the conclusion will indicate that the risk is below the cutoff threshold. If the risk is higher than 1:380, then the woman will be referred for additional consultation with geneticists or offered to undergo invasive diagnostics.

It is worth noting that in cases where, during the first screening, the biochemical analysis met the standards (indicators were calculated HCG and PAPP-A ), then the second and third time the woman only needs to do an ultrasound.

The expectant mother undergoes her last screening examination at third trimester . Many people wonder what they look at at the third screening and when they should undergo this study.

As a rule, if a pregnant woman was not diagnosed with any abnormalities in the development of the fetus or during pregnancy at the first or second examination, then she can only undergo an ultrasound examination, which will allow the specialist to draw final conclusions about the condition and development of the fetus, as well as its position in the womb.

Determination of fetal position ( cephalic or breech presentation ) is considered an important preparatory stage before childbirth.

For delivery to be successful and for a woman to give birth on her own without surgery, the baby must be in a cephalic position.

Otherwise, doctors plan a cesarean section.

The third screening includes procedures such as:

• Ultrasound which all pregnant women without exception undergo;
• dopplerography is a technique that focuses mainly on the condition of blood vessels placenta ;
• cardiotocography – a study that allows you to more accurately determine the heart rate of a child in the womb;
• blood biochemistry , during which attention is focused on such markers of genetic and other abnormalities as the level hCG, ɑ-fetoprotein and PAPP-A .

Timing of the third screening during pregnancy

It is worth noting that only the doctor decides at what week 3 screening a woman should undergo screening, based on the individual characteristics of this particular pregnancy. However, it is considered optimal when the expectant mother undergoes a routine ultrasound at 32 weeks, and then immediately takes a biochemical blood test (if indicated), and also undergoes other necessary procedures.

However, for medical reasons, carry out dopplerography or CTG the fetus is possible starting from the 28th week of pregnancy. Third trimester begins at 28 weeks and ends with childbirth at 40-43 weeks. The last screening ultrasound is usually scheduled at 32-34 weeks.

Interpretation of ultrasound

We have found out at what time a pregnant woman undergoes the third screening ultrasound; now we will talk in more detail about deciphering the study. When performing an ultrasound in the third trimester, the doctor pays special attention to:

• for development and construction of cardio-vascular system child to exclude possible developmental pathologies, for example;
• on proper development brain , abdominal organs, spine and genitourinary system;
• located in the cranial cavity vein of galen , which plays an important role in the proper functioning of the brain, to exclude aneurysm ;
• on the structure and development of the child’s face.

In addition, ultrasound allows a specialist to assess the condition amniotic fluid, appendages and uterus mother, and also check and thickness of the placenta . In order to exclude hypoxia and pathologies in the development of the nervous and cardiovascular systems , as well as to identify the characteristics of blood flow in vessels of the uterus and the child, as well as in the umbilical cord, are carried out dopplerography .

As a rule, this procedure is performed only when indicated simultaneously with ultrasound. In order to exclude fetal hypoxia and determine heart rate, carry out CTG . This type of research focuses solely on the baby's heart function, so cardiotocography prescribed in cases where the doctor has concerns about the condition cardiovascular child's system.

Ultrasound in the third trimester of pregnancy allows you to determine not only the presentation of the baby, but also the maturity of his lungs, on which readiness for birth depends. In some cases, hospitalization for early delivery may be necessary to save the life of the child and mother.

Based on the results of a biochemical blood test MoM coefficient should not deviate from the range from 0.5 to 2.5. The risk value for all possible deviations must correspond to 1:380.

Education: Graduated from Vitebsk State Medical University with a degree in Surgery. At the university he headed the Council of the Student Scientific Society. Advanced training in 2010 - in the specialty "Oncology" and in 2011 - in the specialty "Mammology, visual forms of oncology".

Experience: Work in a general medical network for 3 years as a surgeon (Vitebsk Emergency Hospital medical care, Liozny Central District Hospital) and part-time as a district oncologist and traumatologist. Worked as a pharmaceutical representative for a year at the Rubicon company.

Presented 3 rationalization proposals on the topic “Optimization of antibiotic therapy depending on the species composition of microflora”, 2 works took prizes in the republican competition-review of student scientific works (categories 1 and 3).

Content

A referral for a screening examination causes panic among expectant mothers. A lot of questions arise - what is this, is it dangerous for the baby, why are they sending me? In order not to worry unnecessarily during such a crucial period, it is better to deal with this issue in advance.

What is screening

The Ministry of Health recommends that women expecting a child undergo examinations in the first trimester in order to identify abnormalities in fetal growth in the early stages. Perinatal testing does not seem to pose a threat to the mother and child. The price of the study is affordable, so there is no need to risk the life of the unborn baby. Screening during pregnancy helps to identify:

• genetic pathologies;
• indirect signs of violations;
• fetal malformations.

Everyone who is at risk should be screened during pregnancy in the 1st trimester. These are women who have:

• the father of a child who received radiation;
• age category over 35 years;
• threat of miscarriage;
• hereditary diseases;
• occupational hazard;
• children born with pathologies;
• previous frozen pregnancy, miscarriages;
• family connection with the child's father;
• drug and alcohol addiction.

First screening during pregnancy

It is important to conduct a screening test for the first time if the price at stake is the life of the unborn baby. What can be revealed during the examination? First trimester screening can detect:

• defects of the central nervous system;
• genetic diseases - Edwards, Down syndromes;
• the presence of an umbilical hernia;
• slow growth of skeletal bones;
• disorders of brain formation;
• increased or slow heartbeat;
• one umbilical artery (there should be two).

What do they look for at the first screening?

An important component of the mother’s calm state and confidence in the correct development of the baby are screenings during pregnancy. Important parameters of the fetus are measured during the first ultrasound examination:

• the size between the parietal tubercles;
• TVP – thickness dimension of the collar space;
• KTR size – from the coccyx to the bone on the crown;
• length of bones - forearm, thigh, lower leg, shoulder;
• heart size;
• Head circumference;
• vessel sizes;
• the distance between the frontal and occipital bones;
• heart rate.

First screening during pregnancy - timing

What determines the time of the first screening test? An important indicator in the fetus is the thickness of the collar space. The period when the first screening is done is the beginning of the 11th week; earlier the TVP value is too small. The end of the period is associated with the formation of the fetal lymphatic system. After 14 weeks, the space fills with fluid and can increase, as in pathology - and the results will not be objective. The end of the period is considered to be 13 weeks plus an additional 6 days.

Preparing for 1st trimester screening

An ultrasound examination does not require preparation if the examination is performed through the vagina. When testing through the abdominal wall, you need to fill the bladder with three glasses of water 1.5 hours before starting. How to prepare for the 1st trimester screening, its second component – ​​a blood test? To obtain an objective result you need:

• two days before, do not eat seafood, nuts, chocolate, smoked and fried foods;
• in the morning on the day of the event, do not drink anything;
• donate blood on an empty stomach.

How to do the first screening during pregnancy

Wanting to exclude defects and determine inconsistencies in fetal development, women in the first trimester are sent for examination. After deciphering the results and comparing them with the standards, a decision is made. If indicators are poor, termination of pregnancy is possible. How is 1st trimester screening performed? The study includes two stages:

• ultrasound examination, during which measurements of the fetus are taken, the characteristics of its vital functions and the condition of the uterus are established;
• biochemical analysis of maternal blood, revealing the absence of chromosomal defects.

First screening during pregnancy - norms

After the study, specialists compare the resulting indicators with the standards. An important point is the dependence of these values ​​on the correct stage of pregnancy: in what exact week the test was carried out. The 1st trimester screening standards for ultrasound results are:

• coccyx-parietal size – 34-75 mm;
• the nasal bone is present, not measured at 11, 12 weeks, then the value exceeds 3 millimeters;
• heart rate – 147-178 beats per minute;
• size between the parietal bones – 13-28 mm;
• The thickness of the collar space is in the zone of 0.8 - 2.7 mm.

Biochemical hemoanalyses have their own standards. They are influenced by the week of the study. After receiving the results, the MoM coefficient is calculated using a computer, showing deviations in fetal development. The parameters are proportional to the period:

• beta-hCG – 14.2-130.9 ng/ml;
• calculated MoM coefficient – ​​0.51-2.5;
• PAPP-A – 046- 8.53 mIU/ml.

Ultrasound screening 1st trimester

The main examination of this period is ultrasound. Based on its results (if there are concerns about chromosomal defects), blood tests are prescribed. Screening ultrasound of the 1st trimester checks the fetus, in addition to measuring parameters:

• structure and symmetry of the brain;
• ductus venosus blood flow;
• the presence of an umbilical hernia;
• position of the stomach, heart;
• number of umbilical cord vessels.

During a screening study, measurements and monitoring of the pregnant woman’s condition are carried out. The indicators will tell you about the threats to fetal development. Increased uterine tone can provoke spontaneous abortion. During an ultrasound examination, a woman is diagnosed with:

• location, thickness of the placenta;
• uterine tone;
• amount of amniotic fluid;
• picture of the cervical pharynx.

Biochemical screening

If abnormalities are detected by ultrasound, blood tests are prescribed to clarify the threat of chromosomal pathologies. The results are interrelated with the timing accurately determined by ultrasound examination. Maternal venous blood serum is taken for analysis. Based on the results, the risk of anomalies is calculated. The hemotest determines 2 parameters that are compared with the standard:

• free hCG beta subunit;
• plasma protein A – PAPP-A.

1st trimester screening - interpretation of results

After the research, specialists use computer processing to transcribe the research. The screening results of the 1st trimester depend on the week in which they are carried out and have different indicators. When performing an ultrasound:

• determine the presence and size of the nasal bone - more than 3 millimeters;
• measure the thickness of the collar space - an increased indicator indicates the likelihood of pathology.

Decoding the results of blood biochemistry is also related to the week in which it is carried out:

• beta-hCG levels are below the standard - the likelihood of an ectopic, frozen pregnancy, miscarriage;
• the results are high - toxicosis, the presence of several fetuses, tumors, Down syndrome are possible;
• PAPP-A values ​​are higher than normal – threat of miscarriage, frozen pregnancy;
Video guide 11 week First trimester screening 001