Screening examination during pregnancy. How many screenings and ultrasound examinations are performed during pregnancy, and in what week are these procedures performed? If you get unfavorable results, what to do

30.10.2019

The new word "screening" appears in a woman's vocabulary already in the first trimester of pregnancy. These are tests that show any abnormalities in hormones while carrying a baby.

Screening is done to check for groups at risk of development, such as Down syndrome, neural tube malformations, and Edwards syndrome. The result can be found out after a blood test taken from a vein and an ultrasound scan. The individual characteristics of the pregnant woman and the development of the unborn child are also taken into account. Everything is taken into account - height, weight, bad habits, the use of hormonal drugs.

First trimester screening is a comprehensive examination between 11 and 13 weeks of pregnancy. He must determine the risk of having a baby with congenital malformations. Screening includes two tests - examination and examination of blood from a vein.

The first ultrasound scan determines the physique of the baby, the correct location of the legs and arms. The doctor examines the circulatory system of the fetus, heart function, body length relative to normal. In addition, special measurements are made, such as measuring the thickness of the cervical fold.

It should be borne in mind that the screening of the first trimester is called complex, so it is not worth drawing any conclusions based on only one indicator. If there are suspicions of genetic malformations, the woman is referred for additional research. First trimester screening is optional for all pregnant women. Moreover, in the antenatal clinic, most of these are not done and you have to donate blood in private clinics. However, those women who have an increased risk of pathologies are still referred for screening. These are those who give birth after 35 years of age, who have patients with genetic pathologies in their families, expectant mothers who had miscarriages or children with genetic abnormalities before.

In the first trimester of pregnancy, a blood test determines the content of b-hCG and PAPP-A, a plasma protein associated with pregnancy.

For (16-18 weeks) blood is donated for three hormones - b-hCG, AFP and free estriol, sometimes, as an option, a fourth indicator is added - inhibin A.

Let's figure out a little what these hormones are, and how they can affect the outcome of pregnancy.

HCG is found in maternal serum. It is one of the main hormones in pregnancy. Screening determines. If it is lowered, then this indicates a pathology of the placenta. The increased content of the hormone most often occurs due to chromosomal abnormalities in the fetus or indicates that you are carrying two or more babies.

The PAPP-A test is a determination of the produced protein A in the blood. Screening also determines the level of this protein. If it is significantly underestimated, then this indicates some chromosomal abnormalities, which in turn can lead to the fact that the baby may develop Down syndrome or Edwards syndrome.

Maternal blood levels of estriol, a female sex steroid, are measured by screening during the second trimester of pregnancy. Estriol is produced by the placenta during pregnancy. And if it is not produced enough, then this indicates possible violations in the development of the fetus.

Alpha-fetoprotein (AFP) is found in maternal serum. This is also a specific protein that is produced only during pregnancy. If the normal condition of the fetus is disturbed, then this also affects the results - the blood level decreases or increases. An increase indicates the development of congenital defects and diseases, a decrease - of Down's syndrome. A sharp increase in the amount of AFP can lead to fetal death.

Having the screening results on hand, do not panic if one of the results is not normal. It is important to understand that doctors draw conclusions based on general conclusions, a comprehensive assessment. In addition, even if there is a high risk of fetal malformations, then you need to go to the consultation with a geneticist.

It should be noted that screening only indicates the possibility that there is a problem, in addition, deviations from the norm can be associated with various reasons - taking hormonal drugs during pregnancy or untimely testing.

Specially for- Maryana Surma

From the guest

Girls, I am writing a review in the hope that someone will need my experience. First pregnancy, 33 years old. Pregnancy is very long awaited. Seeing 2 stripes there was no limit to happiness. All the joyful moments after 1 screening are over. The ultrasound is excellent, the collar space is normal. I hand over a blood test - the result is 1:84. The doctor suggests not to worry and pass the 2nd trimester screening (a huge mistake! I wasted time and did not receive the final result). The result of the second screening: excellent ultrasound and blood risk 1:40. Then I do a DNA analysis, the result from Hong Kong is not comforting. Down syndrome probability 1:20, 99%. But the darker the result of the DNA test is not a diagnosis and does not serve as a basis for termination of pregnancy, and the period is already 19 weeks. Further, the geneticist insists on amniocentesis, convincing that the result may be different. I am waiting for the result of the amnio for 3 weeks. During this time I go for an ultrasound scan again. The results are perfect! Nose, limbs, brain, bones, etc. - Everything is okay! I pray 24 hours a day for health, cry, wait, hope. Then I follow the result of amniocentesis and get a verdict - a child with Down syndrome! Naturally, I make the decision to interrupt, since I myself worked in a rehabilitation center with such children and I know that the severity of the treatment is not predictable! From a mild form to an immovable log with a bunch of additional complications on the heart and other organs. Now I am in the hospital and waiting for tomorrow's artificial birth. Girls, summing up, I want to say that if you do not plan to give birth with any diagnosis, do not waste time on unnecessary diagnostics. Ultrasound will not show everything, even with the latest equipment and an experienced doctor. The second screening definitely took me 3 weeks in vain. Now I am lying and crying, and the term is already 23 weeks!

EVERYTHING'S UNDER CONTROL

There are a number of studies, thanks to which the risk of giving birth to a child with pathologies such as Down syndrome, Edwards syndrome and gross malformations is detected at the earliest stages of pregnancy. It is about prenatal screening.

What is it?

Of all the expectant mothers who have passed the examination, a group of women is identified, whose results differ significantly from the norm. This suggests that their fetus is more likely to have some pathologies or defects than others. Prenatal screening is a complex of studies aimed at identifying developmental abnormalities or gross malformations of the fetus.

The complex includes:

Biochemical screening is a blood test that allows you to determine the presence in the blood of specific substances ("markers") that change in certain pathologies, such as Down syndrome, Edwards syndrome and neural tube malformations. By itself, biochemical screening is only a confirmation of the likelihood, but not a diagnosis. Therefore, additional research is being done with it;

Ultrasound screening (ultrasound) - is performed in each trimester of pregnancy and allows you to identify most of the anatomical defects and developmental anomalies of the child. Prenatal screening consists of several stages, each of which is important, as it provides information about the development of the child and possible problems.

Risk factors for the development of pathology in an unborn child:

- the woman is over 35 years old;

- the presence of at least two spontaneous abortions in early pregnancy;

- the use of a number of pharmacological drugs before conception or in early pregnancy;

- bacterial, viral infections transferred by the expectant mother;

- the presence in the family of a child with genetically confirmed Down syndrome, other chromosomal diseases, congenital malformations;

- family carriage of chromosomal abnormalities;

- hereditary diseases in close relatives;

- radiation exposure or other harmful effects on one of the spouses before conception.

First trimester examinations

"Double test"

Carried out from the 10th to the 14th week of pregnancy (the optimal time is from the 11th to the 13th week)

Combined screening

- Ultrasound procedure, during which the main parameters are measured: coccyx-parietal size (CTE) and the thickness of the collar space (TVP). TVP greater than 3 mm may indicate possible fetal developmental abnormalities. Additional research is required to confirm (or refute). Screening is informative only when the CTE of the fetus is equal to or greater than 45.85 mm.

– Biochemical screening:

- blood test for hCG

- RAPP-A (PAPP-A).

It is necessary to start the examination with ultrasound screening, since the obtained indicators can reveal factors that make the results of biochemistry uninformative, for example, more accurate periods of pregnancy (not corresponding to the period of 11-13 weeks), multiple pregnancies, problems with the development of pregnancy (for example, stopping) ... The data obtained during the ultrasound scan will be used to calculate the risks, both in the first and in the second trimester of pregnancy.

If the results of an ultrasound scan correspond to the required timing of its conduct, then biochemical screening (donating blood) can be done. The optimal terms for this are the same as for an ultrasound scan - 11-13 weeks. It is important to meet this time. The gap between ultrasound screening and biochemistry should be a maximum of 3 days.

What does biochemical screening investigate?

- Free subunit of human chorionic hormone (hCG)

- PAPP-A - pregnancy-related protein A.

The hCG hormone is produced by the cells of the membrane of the embryo (chorion). It is thanks to the analysis for hCG that pregnancy can be determined already on the 6-10th day after fertilization. The level of this hormone rises in the first trimester and reaches its maximum by the 10-12th week. Then it gradually decreases and remains constant during the second half of pregnancy.

The hCG hormone consists of two units (alpha and beta). Of these, a unique beta is used in diagnostics.

If the level of beta-hCG is elevated, this may indicate:

- multiple pregnancies (the hCG rate increases in proportion to the number of fruits);

- Down syndrome and some other pathologies;

- toxicosis;

- diabetes mellitus in the expectant mother;

- incorrectly set period of pregnancy.

If the level of beta-hCG is lowered, this may indicate:

- the presence of an ectopic pregnancy;

- undeveloped pregnancy or the threat of spontaneous abortion;

- delayed development of the unborn baby;

- placental insufficiency;

- fetal death (in the second or third trimester of pregnancy).

RATES OF HCG IN BLOOD SERUM

HCG level during pregnancy HCG norm, mU / ml

1st - 2nd week 25 - 300

2nd - 3rd week 1500 - 5000

3-4th week 10,000-30,000

4th - 5th week 20,000 - 100,000

5-6th week 50,000-200,000

6-7th week 50,000-200,000

7 - 8th week 20,000 - 200,000

8-9th week 20,000-100,000

9-10th week 20,000 - 95,000

11-12th week 20,000- 90,000

13-14th week 15000-60,000

15-25th week 10000-35000

26-37th week 10000-60000

RARR-A (PAPP-A)- a protein that modulates the immune response of the maternal body and is one of the factors that ensure the work of the placenta. The analysis is carried out in the first trimester of pregnancy.

A decrease in the level of PAPP-A indicates the likelihood:

- chromosomal abnormalities of the fetus;

- Down syndrome, Edwards, Cornelie de Lange;

- threats of miscarriage or termination of pregnancy.

RAPP-A NORMS IN BLOOD SERUM

Week of pregnancy Norm PAPP-A, honey / ml

8-9th week 0.17-1.54

9-10th week 0.32- 2.42

10-11th week 0.46-3.73

11-12th week 0.7- 4.76

12-13th week 1.03-6.01

13-14th week 1.47-8.54

MoM - to calculate risk indicators, not specific data obtained are used, but the so-called MoM. This is a coefficient showing the degree of deviation of the value of one or another indicator of prenatal screening from the average value (median) for the gestational age.

It is calculated using the following formula:

MoM = serum value divided by the median value for a given gestational age

The norm is the value of the indicator close to one.

There are a number of factors that can affect the value of the obtained indicators:

- weight of a pregnant woman

- taking medications;

- a history of diabetes mellitus in the expectant mother;

- the onset of pregnancy as a result of IVF.

Therefore, when calculating risks, doctors use the MoM value adjusted taking into account all the features and factors.

The MoM level rate ranges from 0.5 to 2.5. And in the case of multiple pregnancies, up to 3.5 MoM.

Depending on the results obtained, it will be clear whether the expectant mother is at risk for chromosomal pathologies or not. If so, your doctor will advise you to do further research.

Do not worry in advance if you have been assigned a second trimester screening - it is recommended for all pregnant women, regardless of the results of the first stage of the examination. God saves man, who save himself!

Second trimester examinations

"Triple test"

Carried out from the 16th to the 20th week of pregnancy (the optimal time is from the 16th to the 18th week)

Combined screening

– Ultrasound procedure(using data from the first trimester).

– Biochemical screening:

- blood test for AFP;

- free estriol;

- chorionic gonadotropin (hCG)

The second screening is also aimed at identifying the degree of risk of having a baby with Down syndrome, Edwards syndrome, neural tube defect and other abnormalities. During the second screening, studies of the placenta hormone and fetal liver hormone are carried out, which also carry the necessary information about the development of the child.

Alpha-fetoprotein(AFP) is a protein present in the blood of a child in the early stages of embryonic development. It is produced in the liver and gastrointestinal tract of the fetus. Alpha-fetoprotein works to protect the fetus from the maternal immune system.

An increase in the AFP level indicates the likelihood of existence:

- malformation of the neural tube of the fetus (anencephaly, spina bifida);

- Meckel's syndrome (sign - occipital cranial hernia);

- atresia of the esophagus (pathology of intrauterine development, when the fetus's esophagus blindly ends without reaching the stomach (the child cannot take food through the mouth);

- umbilical hernia;

- non-union of the anterior abdominal wall of the fetus;

- necrosis of the fetal liver due to a viral infection.

A decrease in the AFP level suggests:

- Down syndrome - trisomy 21 (after 10 weeks of pregnancy);

- Edwards syndrome - trisomy 18;

- incorrectly defined gestational age (more than needed for the study);

- fetal death.

AFP RATES IN BLOOD SERUM

Week of pregnancy AFP level, U / ml

13-15th 15-60

15-19th 15-95

20-24th 27- 125

25- 27th 52- 140

28-30th 67-150

31- 32nd 100-250

Free estriol this hormone is produced first by the placenta, and subsequently by the liver of the fetus. During the normal course of pregnancy, the level of this hormone is constantly increasing.

An increase in estriol levels can indicate:

- multiple pregnancy;

- large fruit;

- diseases of the liver, kidneys in the expectant mother.

A decrease in estriol levels may indicate:

- fetoplacental insufficiency;

- Down syndrome;

- fetal anencephaly;

- the threat of premature birth;

- hypoplasia of the fetal adrenal glands;

- intrauterine infection.

NORMS OF ESTRIOL IN BLOOD SERUM

Pregnancy week Free estriol rate

6-7th week 0.6-2.5

8-9th week 0.8- 3.5

10-12th week 2.3-8.5

13-14th week 5.7-15.0

15-16th week 5.4-21.0

17-18 weeks 6.6-25.0

19-20th week 7.5-28.0

21-22 weeks 12.0-41.0

23-24th week 18.2- 51.0

25-26th week 20.0-60.0

27-28th week 21.0- 63.5

29-30th week 20.0-68.0

31- 32nd week 19.5- 70.0

33-34th week 23.0-81.0

35-36th week 25.0- 101.0

37- 38th week 30.0- 112.0

39-40th week 35.0- 111.0

Third trimester ultrasound screening

Carried out from the 30th to the 34th week of pregnancy (the optimal time is from the 32nd to 33rd weeks)

During ultrasound, the state and location of the placenta is studied, the amount of amniotic fluid and the location of the fetus in the uterus are determined.

According to the indications, the doctor may prescribe additional studies - dopplerometry and cardiotocography.

Doppler this study is done starting at the 24th week of pregnancy, but most often doctors prescribe it after the 30th week.

Indications for carrying out:

– placental insufficiency;

- insufficient increase in the height of the uterine fundus;

- entanglement of the umbilical cord;

- gestosis, etc.

Doppler This is an ultrasound method that provides information about the blood supply to the fetus. The speed of blood flow in the vessels of the uterus, umbilical cord, middle cerebral artery and fetal aorta is investigated and compared with normal indicators for a given period. Based on the results, conclusions are drawn about whether the blood supply to the fetus is normal, whether there is a lack of oxygen and nutrients. If necessary, drugs are prescribed to improve the blood supply to the placenta.

Cardiotocography (CTG) - a method of recording the fetal heartbeat and its changes in response to uterine contraction. Recommended from the 32nd week of pregnancy. This method has no contraindications.

CTG is performed using an ultrasound sensor, which is fixed on the pregnant woman's abdomen (usually external, so-called indirect CTG is used). The duration of CTG (from 40 to 60 minutes) depends on the phases of activity and rest of the fetus. CTG can be used to monitor the baby's condition both during pregnancy and during childbirth itself.

Indications for CTG:

- diabetes mellitus in the expectant mother;

- pregnancy with a negative Rh factor;

- detection of antiphospholipid antibodies during pregnancy;

- fetal growth retardation.

Only your decision

The doctor directs for screening and (if necessary) recommends further examination, but he should not influence the woman's decision in any way. Many expectant mothers initially refuse screening studies, citing the fact that they will give birth anyway, regardless of the results of the study. If you are one of them and do not want to do a screening, then it is your right, and no one can force you.

The doctor's role is to explain why such screenings are carried out, what diagnoses can be made as a result of the studies, and in the case of using invasive diagnostic methods (chorionic biopsy, amniocentesis, cordocentesis), to tell about the possible risks. After all, the risk of termination of pregnancy after such examinations is about 2%. The doctor should also warn you about this.

Unfortunately, doctors do not always have enough time to explain the screening results in detail.

During pregnancy, a woman is regularly scheduled to undergo a number of specific medical examinations. Their purpose is to determine the state of health of the child and the compliance of the degree of his development with the established norms. The complex of these diagnostic procedures is called screening.

Translated from English, the word "screening" literally means "sorting", "selection" or "sifting", which fully reflects the essence of the research. With their help, doctors calculate how likely it is that a child in the womb will be born with some kind of genetic disorder.

Based on the results obtained, specialists determine a group of healthy patients. All the rest are assigned to undergo additional medical tests and analyzes, with the help of which they reveal the presence of a specific disease in the baby.

A screening study is carried out at certain stages of pregnancy in every antenatal clinic. This procedure is absolutely free for all expectant mothers who are registered..

In recent years, due to the increase in the age of women giving birth, this survey has played a special role. It has been proven that in women over 35 years of age, the likelihood of having a baby with congenital anomalies is much higher.

Even based on the results of screening, it is impossible to say with absolute certainty that a sick child is developing in the womb, and no one can say this. All of the above studies only indicate how high the probability of giving birth to a particular woman (taking into account her age and information from the medical record) of a baby with certain genetic pathologies.

Indications

According to the WHO recommendations, as well as the corresponding order of the Ministry of Health of the Russian Federation, a standard perinatal screening study is recommended for all women carrying a child. In other words, the state of pregnancy in itself is an indication for the passage of this examination.

But no one has the right to oblige the expectant mother to do an ultrasound scan or donate blood. These simple, safe procedures are voluntary. However, there are situations when the results of standard analyzes are not enough.

future mothers over 35 years old or, if the child's father is over 40 (it does not matter at all how many pregnancies, births a woman had before);
patients who have children with some kind of disabilities;
women who had at least 2 previous pregnancies that were unsuccessful (premature birth or spontaneous miscarriages);
expectant mothers with experience of a frozen pregnancy;
women who suffered during the first trimester of some kind of infectious disease or took medications and medications prohibited for pregnant women (for example, antibiotics, psychostimulants or hormonal drugs) between the 1st and 13th obstetric weeks;
pregnant women who are consanguineous with the father of the unborn baby;
patients who were exposed to radiation before pregnancy (or, if the father of the unborn baby was exposed to it);
women in whose family there are cases of the birth of children with some kind of genetic disorder (or, if the future father has such relatives);
pregnant women, workers in hazardous work;
expectant mothers carrying a child with unknown paternity (for example, if conception occurred as a result of in vitro fertilization using sperm from an unknown donor);
women who have some kind of bad habits.

In all these cases, the risk of developing some congenital abnormalities and chromosomal abnormalities in the embryo increases.

If, according to the results of the standard screening, this probability is confirmed, the expectant mother is prescribed a referral to undergo invasive methods of prenatal diagnosis.

A complete perinatal examination is considered optional and optional. It is carried out only at the request of the patient herself. But in some cases, the doctor may insist on a full examination in order to find out about the hidden risks and dangers as early as possible and to correct the further management of pregnancy in time.

During the gestation period, a woman is referred for antenatal screening three times:

In the 1st trimester (between the 10th and 14th obstetric weeks).
In the 2nd trimester (between the 15th and 20th obstetric weeks).
In the 3rd trimester (between the 30th and 34th obstetric weeks).

HCG norms

Human chorionic gonadotropin(abbreviated as hCG, hCG, HCG in English, hCG in Ukrainian) is a hormone that, in the normal state of the body, is produced exclusively during pregnancy.

The hCG hormone is produced after conception - it is synthesized by the fertilized egg, and after the trophoblast is formed (this is the precursor of the placenta), this hormone is produced by its tissues. That is why the level of hCG is determined only after conception.

HCG table during pregnancy Norm by week

Contraindications

Screening during pregnancy is not limited to any contraindications. All methods that are used during standard diagnostics do not pose any danger either for the expectant mother or for the child. In certain situations, the doctor may cancel or postpone the examination so as not to distort its indicators.

Conditions of a pregnant woman that may affect the results of antenatal diagnostics include:

colds (ARI);
infectious diseases (including tonsillitis, ARVI).

Before going for an antenatal check-up, a woman should visit her obstetrician-gynecologist. If the doctor discovers signs of a disease in the expectant mother, he will refer her to a narrow specialist (therapist, infectious disease specialist or ENT) for consultation.

The use of invasive research methods, on the contrary, can increase the risk of premature termination of pregnancy, since they imply surgical intervention in the woman's body. But they are prescribed and carried out only if there are indications for that.

Features of the procedure

With the help of a perinatal study, specialists determine how likely it is that the child will be born with one of the known genetic pathologies:

Down syndrome;
Edwards syndrome;
anencephaly (violation of the formation of the neural tube of the fetus);
Shereshevsky-Turner syndrome (Turner syndrome);
Smith-Lemli-Opitz syndrome;
Cornelia de Lange syndrome (Amsterdam dwarfism);
Patau syndrome;
non-molar triplodia.

All of the above deviations, if confirmed after additional diagnostics, can become a sufficiently compelling medical indication for terminating pregnancy at any time.

But the final decision is always made by the woman herself, and no one has the right to force her.

Screening during pregnancy consists of a number of different examination methods, among which are:

Ultrasound examination (ultrasound) of the fetus... With its help, a specialist studies the structural features of the embryo. Based on the results obtained, doctors identify markers of possible chromosomal pathologies. Also, this type of examination includes cardiotocography (the study of a child's heartbeat) and ultrasound Doppler (a method for examining blood flow in the umbilical cord).

Blood chemistry... This is a method for detecting in the serum of the plasma of the expectant mother the amount of certain proteins that can indicate the possibility of some abnormalities in the child.
Invasive methods... These are additional examinations. They are not prescribed to everyone, but only to those patients, according to the results of the above analyzes, which revealed a high risk of detecting chromosomal pathologies in a child.

These include the following medical research:

Preparation for research

Screening during pregnancy is an important and serious study that requires some preparation. Before the examination, a woman necessarily receives advice and recommendations from medical personnel regarding what preparatory measures are required for the test ahead of her.

The mom-to-be shouldn't worry. You need to set yourself up for a positive outcome of events. Excessive stress and emotional stress affect the work of the whole organism, in particular, it affects the functioning of most organs and the production of hormones. As a result, test results may be false.
To undergo a transvaginal ultrasound, you must bring a condom. It is also better to visit the toilet before the examination to feel more comfortable.
On the contrary, a pregnant woman should come to a transabdominal ultrasound scan with a full bladder. It is best to drink 1 or 2 glasses of plain water about half an hour before the study.
If the expectant mother suffers from flatulence, it is recommended that she drink drugs that help reduce gas formation the day before the ultrasound scan, and also not eat foods that can aggravate this situation.
Blood sampling for biochemical analysis is performed on an empty stomach, so you cannot eat anything 4-6 hours before. Material for research is taken from a vein.
Before the examination for 3 days, it is necessary to give up intimacy, eating fried, spicy and fatty foods.
Before going to the clinic, you need to weigh yourself and ask the father of the unborn child about whether he has had any cases of chronic diseases transmitted by inheritance in his family. The doctor will need this information to complete the form.

First screening

The first antenatal examination is prescribed for the period from the 10th to the 14th obstetric week of pregnancy.

First of all, a woman comes to an appointment with an obstetrician-gynecologist, who performs a general examination, which includes:

blood pressure measurement;
weighing;
measuring growth;
identifying the presence of any chronic diseases in the patient.

If necessary, the expectant mother is prescribed a referral for an appointment with narrow specialists for consultation. At the same time, the woman must pass a general urine test. Also, blood is taken from her to detect the presence of diseases such as hepatitis, HIV, syphilis and to determine the group with the Rh factor.

Be sure to do an ultrasound, on the basis of which the specialist:

visually evaluates the course of pregnancy;
determines the location of the ovum (uterine or ectopic);
calculates the number of embryos;
if there are several children, determines what kind of twins will be (identical or fraternal);
assesses the tone of the uterus, analyzes the state of the ovaries of the expectant mother;
studies the chorion;
looks at how developed the brain and spine are in the fetus, checks for the presence of limbs in the embryo.

Screening is a routine set of diagnostic procedures that are performed during pregnancy and help monitor the intrauterine development of the child and identify possible genetic abnormalities.

The first stage of genetic research involves assessing the possibility of detecting any of the most common genetic defects in a child.

Among them there are syndromes:

Down;
Turner;
Edwards;
Patau.

The first stage of perinatal diagnostics is completed by a woman's blood test for biochemistry. This test verifies the data on the values of free beta-hCG and PPAP-A in plasma. Therefore, the analysis is often referred to as "Double Test".

Second screening

The next antenatal check-up is performed from the 15th to the 20th obstetric week of pregnancy.

In the second stage, the main goal of doctors is to refute or confirm the risks that were suspected after the examination carried out at the beginning of pregnancy. If there are indeed abnormalities, the probability of their diagnosis in the second trimester is about 90%.

Chromosomal abnormalities are not treated, but disorders in the formation of the fetal neural tube can be tried to be corrected or at least minimized even before delivery.

The second stage of perinatal diagnosis consists of an abdominal ultrasound scan and a blood biochemistry test. The latter now consists of a study of 3 factors and is called the "Triple Test".

On an ultrasound examination, the doctor determines the likelihood of developing dysplasia of the child's skeleton, assesses the presentation of the fetus and the specifics of its anatomical structure:

the length of the bones of all limbs;
Head circumference;
chest circumference;
circumference of the abdominal region.

The structure of the following organs of the child is also being studied:

ventricles of the brain;
cerebellum;
of cardio-vascular system;

In addition, bone structure is examined:

spine;
skull;
chest.

A woman's blood biochemistry test involves checking the concentration of substances such as hCG, AFP and free estriol.

Third screening

The last antenatal check-up takes place between the 30th and 34th obstetric weeks of pregnancy.

At this stage, specialists assess the risks of possible complications and premature termination of pregnancy, determine the method of delivery and identify indications for a caesarean section. In addition, some defects form late in pregnancy. They can only be detected at the last screening.

The last 3rd stage of prenatal diagnosis includes abdominal ultrasound, ultrasound and CTG.

During the study, using an ultrasound machine, the specialist re-evaluates all the same indicators as the previous time. It also checks if there are any complications of pregnancy and abnormalities in the baby.

The doctor examines in detail:

umbilical cord;
placenta;
amniotic fluid (amniotic);
the cervix of the expectant mother;
appendages of a pregnant woman.

Dopplerometry examines blood flow in:

vessels of the fetus;
the umbilical cord;
woman's uterus;
placenta of a pregnant woman.

In addition, doctors assess the degree of maturity of the placenta, check how it functions, reveal the presence of complications such as cord entanglement and a defect in the baby's heart muscle.

During cardiotocography, a specialist checks whether the fetus is suffering from oxygen starvation, examines the baby's heart rate, the degree of his motor activity, and assesses the tone of the expectant mother's uterus.

Screening ultrasound

An ultrasound scan is one of the very first tests that a pregnant woman undergoes.

According to the results of the procedure, the specialist evaluates:

the state of the embryo as a whole;
compliance of the child's developmental level with the established gestational age;
the fact of obvious violations of the development of the embryo;
any additional external defects.

Even if the latter were not found during the examination, this cannot guarantee that everything is in perfect order with the baby. For the most accurate research, a biochemical blood test is performed.

Blood chemistry

The biochemistry test is the most reliable known method for diagnosing genetic diseases in a child. Blood is drawn from a vein. This usually happens on the same day as the ultrasound procedure.

To get the most reliable answer, it is better to take the test in the early morning and on an empty stomach. Also, an important role is played by the observance of all necessary measures during the delivery of the obtained material to the laboratory and its storage before the start of the study.

Blood is examined according to the following indicators:

concentration of specific investigated components in it;
the presence of a unique substance secreted by the placenta;
the amount of specific proteins in the plasma.

In addition, at the doctor's appointment, you will need to fill out a standard questionnaire with questions regarding the following points:

the presence of people with chromosomal defects among the relatives of the father and mother of the unborn child;
the state of health of children already born in the family (if any);
whether the pregnant woman suffers from diabetes mellitus;
does the expectant mother have bad habits (in particular, smoking);
age, height and weight of the woman.

Indicator standards

First screening
Research data	Indicator standards
CTE	43-65 mm
BPR	17-24 mm
TVP	1.6-1.7 mm
Nasal bone size	2-4.2 mm
Heart rate (heart rate)	140-160 (+/- 40) beats / min.
Amniotic water volume	50-100 ml
Woman's cervix	35-40 mm
Yolk sac	"Not visualized"
beta-hCG	50,000-55,000 mIU / ml
RAPP-A	0.79-6.01 mU / l
Second screening
Investigated parameters	Indicator standards
BPR	26-56 mm
DBK (thigh bone size)	13-38 mm
Duodenum (shoulder bone size)	13-36 mm
OG	112-186 mm
IAZh	73-230 mm
Woman's cervix	40-45
Visualization	"Satisfactory"
beta-hCG	4.67-5.27 ng / ml
Free estriol	1.17-3.8 ng / ml
AFP	15-27 U / ml
Third screening
Investigated parameters	Indicator standards
BPR	67-91 mm
DBK	47-71 mm
KDP	44-63 mm
OG	238-336 mm
IAZh	82-278 mm
Placenta thickness	23.9-43.8mm
Placenta maturity	1st degree

What affects the result

Sometimes an antenatal screening result is false.

The reasons for data distortion can be the following factors:

excess weight of the expectant mother;
IVF application;
carrying multiple pregnancies;
stress and depression of a woman;
diagnosis of diabetes mellitus in the expectant mother;
blood sampling a week after the amniocentesis procedure.

Decoding the results

Specialists are involved in decoding the results of prenatal diagnostics.

During the 1st perinatal study, doctors evaluate the following main indicators:

In the second prenatal examination, the doctor assesses additional parameters:

Amniotic fluid index (AFI)... In fact, this is the calculation of the amount of water in the fetal bladder. If they are not enough, there is a danger for the formation of the skeleton and the central nervous system of a small person.
Placenta attachment site... Placing an organ on the anterior surface of the uterus often becomes the main cause of premature placental abruption.
Umbilical cord... If she has only 1 artery instead of 2, then there is a risk of oxygen starvation of a nascent person or the development of a heart muscle defect in him. In addition, a lack of oxygen can provoke an excessively small weight of the fetus, as well as abnormalities in the work of the cardiovascular system of the embryo.
Visualization. The formation of severe edema or hypertonicity of the uterus can impair the clarity of the ultrasound image.
Free estriol. According to the indicators of this special hormone, the doctor judges the state of the placenta. Increased data can be observed when carrying several children or one, but large. Too small numbers are often a symptom of the development of placental insufficiency, carrying a child with anencephaly or Down's syndrome, and the existence of a risk of pregnancy loss.
AFP... A unique protein produced by the small human gastrointestinal tract. A reduced level of its content in the mother's plasma is often directly related to the threat of miscarriage, intrauterine fetal death, and the presence of Down syndrome or Edwards syndrome in the child. High rates are often observed with the development of anencephaly, Meckel's syndrome or underdevelopment of the esophagus (atresia) in a baby.

When examining the umbilical cord, doctors look at the place of attachment of the umbilical cord: a sheath, split or marginal location often causes hypoxia in the child and causes certain difficulties in childbirth. In the presence of any of these diagnoses, the doctor may prescribe a cesarean section for the patient.

In the third stage of antenatal screening, 2 important additional indicators are studied:

Placenta thickness... Too thick placenta is most often observed with Rh-conflict, diabetes or anemia.
Placenta maturity... Due to the rapid aging and an increase in the thickness of the temporary organ, some dangerous conditions can occur: premature birth, delayed child development, hypoxia in the baby.

What to do if the results are unfavorable

If, according to the results of the tests carried out, a woman is placed in a risk group, this does not mean that the child will necessarily be born sick.

A pregnant woman in this situation should:

Heed the advice of your doctor... Such a medical report may well serve as a reason for passing additional tests, after which specialists will already be able to provide an accurate answer.
You need to weigh the pros and cons... Additional examinations are carried out on such terms that allow you to think carefully about everything and make an informed decision: to keep the pregnancy or to terminate it.

Screening is essential during pregnancy. Many deviations, if diagnosed in a timely manner, are treatable. If you do not neglect such an important examination, you can save the life and health of an unborn baby.

Pregnancy Screening Videos

Prenatal screenings in the 1st and 3rd trimester of pregnancy:

To eat or not to eat? And if so, what? Do I need an ultrasound on the day of blood donation? Can I donate blood in the morning? And a week after the ultrasound? What should you do before your first trimester screening? Do I need to take a second screening during pregnancy? And in what time frame?

In our clinics, dozens of women undergo screenings for the 1st and 2nd trimester every day: they do an ultrasound scan and donate blood. And when you visit a doctor or a treatment room, the most incredible questions and opinions about these studies are voiced.
The rules for taking blood tests for screening are overgrown with myths and legends. It's time to get rid of them.

So, the myths about preparing to donate blood for biochemical screening during pregnancy(double test, quadruple test, risk assessment of gestosis)

1. You need to take the first screening at 12 weeks, plus or minus 5 days, and the second - no later than 18 weeks.
This is not true. The deadlines for passing the screening are from 11 to 13 weeks 6 days, and the second - from 14 to 20 weeks (optimally from 16 to 18, but possibly later).

2. You can donate blood for screening only in the morning.
Fluctuations in the biochemical parameters of screening during the day are not observed, therefore, it is not necessary to take it specially in the morning. The main thing is not earlier than 3-4 hours after the last meal (do not eat fatty foods).

3. Before each screening, you need to undergo an ultrasound scan.
Ultrasound screening of the 1st trimester is done before donating blood for a double test, and the next ultrasound is done from 19 to 21 weeks, when the second trimester screening (quadruple test) has already been passed. A first-trimester ultrasound scan with TBP and nasal bones is involved in calculating the risk in both screenings.
Recommendations on one of the sites are incorrect:
"Blood should not be donated immediately after an ultrasound scan." In the case of screening, most women donate blood immediately after the first ultrasound scan, so as not to go to the clinic twice.

4. Before donating blood, you must follow a diet for several days with the exception of highly allergenic foods, including citrus, chocolate and red fruits and vegetables. Other recommendations prohibit drinking sweet soda and drinking refreshing lozenges on the day of the test.
We see no reason to deny ourselves these products in preparation for screening.

6. Cancel all medications 3 days before the test.
Cancellation of medications during pregnancy can only be done by a doctor. You do not need to do this before donating blood for screening! But it is very important to indicate the medications taken for a correct assessment of the results.

7. Do not donate blood for screening if you are nervous or have a cold.
Also a myth. But we still wish you a calm, easy and healthy pregnancy!

8. You can donate blood only on the day of ultrasound.
No, that's not true either. It is important to have an ultrasound scan and donate blood within the specified screening range. We recommend donating blood after performing an ultrasound scan, since an ultrasound scan establishes the duration and adequacy of the development of pregnancy, and also determines the indicators that are important for the calculation.

10. If the first screening is good, the second screening is not needed.
This is not true. The second screening complements the first, including the identification of other conditions that are not determined in the first screening.

11. If the ultrasound scan is good, you do not need to donate blood.
Ultrasound of the first trimester does not reveal 100% of chromosomal abnormalities, some conditions may not yet be visible. A blood test can determine a pathology that is not yet visible on ultrasound.

So,
treat the recommendations with common sense. For example, among other recommendations before screening on one site, we even found the following: "Before taking blood, it is advisable to exclude the use of ... oral contraceptives." It is clear that these are just general rules that are copied to all analyzes. There were also recommendations about fasting for at least 12 hours.
Before passing the screening, continue to lead your normal life, eat as usual, do not come up with a low-allergenic non-red diet, continue to exercise for pregnant women.
You can also eat and drink on the day of screening. You should not eat for 3-4 hours immediately before taking the test, and also eat fatty foods. No, this will not affect the test result, but in some cases it may require a retake.
The most important thing from preparation is meet the deadlines for passing the screening.

Health and easy pregnancy!

Screening of the 1st trimester is a diagnostic study that is carried out for pregnant women at risk from 10 to 14 weeks. It, being the first of two screening observations, allows you to determine with great accuracy how high the risk of having a sick fetus is. Such an examination consists of two parts - blood donation from a vein and an ultrasound scan. Based on them, taking into account many of your individual factors, the geneticist makes his verdict.

Screening (from the English. "Screening") is a concept that includes a number of measures for the detection and prevention of diseases. For example, screening during pregnancy provides the doctor with complete information about the various risks of pathologies and complications in the development of the child. This makes it possible to take in advance the full range of measures to prevent diseases, including the most severe ones.

Who needs to be screened for the 1st trimester

It is very important that the following women undergo the study:

closely related to the child's father
who have had 2 or more miscarriages (preterm birth)
had a frozen pregnancy or stillbirth
the woman has suffered a viral or bacterial disease during pregnancy
there are relatives suffering from genetic pathologies
this couple already has a child with Patau syndrome, Down syndrome or others
there was an episode of treatment with drugs that cannot be used during pregnancy, even if they were prescribed for vital signs
pregnant over 35 years old
both parents-to-be want to check the likelihood of having a sick fetus.

What they look for at the first ultrasound screening during pregnancy

What do they look at at the first screening? The length of the embryo is assessed (this is called the coccygeal-parietal size - CTE), the size of the head (its circumference, biparietal diameter, the distance from the forehead to the occiput).

The first screening shows the symmetry of the cerebral hemispheres, the presence of some of its structures, which are mandatory in this period. Look at 1 screening also:

long tubular bones, the length of the humerus, femur, forearm and lower leg is measured
whether the stomach and heart are in certain places
the size of the heart and the vessels outgoing from them
the size of the abdomen.

What pathology does this examination reveal?

The first pregnancy screening is informative in terms of detecting:

pathology of the rudiment of the central nervous system - neural tube
Patau syndrome
omphalocele - an umbilical hernia, when a different number of internal organs are located outside the abdominal cavity, and in the hernial sac above the skin
Down syndrome
triploidy (triple set of chromosomes instead of double)
Edwards syndrome
Smith-Opitz syndrome
de Lange syndrome.

The timing of the study

When should the first screening be done? The timing of the diagnosis of the 1st trimester is very limited: from the first day of the 10th week to the 6th day of the 13th week. It is better to do the first screening in the middle of this range, at 11-12 weeks, since the error in the calculations significantly reduces the accuracy of the calculation.

Your doctor should once again scrupulously and thoroughly, depending on the date of the last menstrual period, calculate how long you should undergo the first examination of this kind.

How to prepare for the study

First trimester screening is done in two stages:

First, an ultrasound screening is done. If this is done transvaginally, then no preparation is required. If by the abdominal method, then it is necessary that the bladder is full. To do this, you need to drink half a liter of water half an hour before the study. By the way, the second screening during pregnancy is carried out transabdominally, but does not require preparation.
Biochemical screening. This word refers to the collection of blood from a vein.

Given the two-stage study, preparation for the first study includes:

filling the bladder - before 1 ultrasound screening
fasting for at least 4 hours before taking blood from a vein.

In addition, a diet is needed before the diagnosis of the 1st trimester in order for the blood test to give an accurate result. It consists in excluding the intake of chocolate, seafood, meat and fatty foods the day before you plan to attend a screening ultrasound scan during pregnancy.

If you plan (and this is the best option for carrying out perinatal diagnostics of the 1st trimester) to undergo ultrasound diagnostics and donate blood from a vein in one day, you need:

all the previous day, deny yourself allergenic products: citrus fruits, chocolate, seafood
exclude completely fatty and fried foods (1-3 days before the study)
before the study (usually blood is donated for screening for 12 weeks before 11:00) go to the toilet in the morning, then either not urinate for 2-3 hours, or an hour before the procedure, drink half a liter of water without gas. This is necessary if the study will be performed through the abdomen.
if ultrasound diagnostics is done with a vaginal probe, then preparation for the 1st trimester screening will not include filling the bladder.

How the research is done

How is the study for malformations done in the 1st trimester?

It, like the examination of 12 weeks, consists of two stages:

Ultrasound screening during pregnancy. It can be performed both vaginally and through the abdomen. It doesn't feel any different from an ultrasound scan at 12 weeks. The difference is that it is performed by sonologists who specialize specifically in prenatal diagnostics using high-end equipment.
Blood sampling from a vein in an amount of 10 ml, which should be carried out on an empty stomach and in a specialized laboratory.

How is the 1st trimester screening diagnostics carried out? First, you have your first pregnancy ultrasound. It is usually performed transvaginally.

Decoding the results

1 Normal ultrasound data

Deciphering the first screening begins with the interpretation of the ultrasound diagnostic data. Ultrasound standards:

Coccygeal-parietal size (CTE) of the fetus

When screened at 10 weeks, this size is in the following range: from 33-41 mm on the first day of 10 weeks to 41-49 mm - on 6 days of 10 weeks.

Screening for 11 weeks - CTE norm: 42-50 mm on the first day of 11 weeks, 49-58 - on its 6th day.

During pregnancy of 12 weeks, this size is: 51-59 mm at 12 weeks exactly, 62-73 mm - on the last day of this period.

2. Thickness of the collar area

Ultrasound rates of the 1st trimester in relation to this most important marker of chromosomal pathologies:

at 10 weeks - 1.5-2.2 mm
screening for 11 weeks is represented by a norm of 1.6-2.4
at week 12, this figure is 1.6-2.5 mm
at 13 weeks - 1.7-2.7 mm.

3. Nasal bone

Deciphering an ultrasound scan of the 1st trimester necessarily includes an assessment of the nasal bone. This is a marker, thanks to which it is possible to assume the development of Down syndrome (for this, screening of the 1st trimester is done):

at 10-11 weeks, this bone should already be detected, but its size has not yet been estimated
screening at 12 weeks or one week later shows that this bone is at least 3 mm normal.

4. Heart rate

at 10 weeks - 161-179 beats per minute
at 11 weeks - 153-177
at 12 weeks - 150-174 beats per minute
at 13 weeks - 147-171 beats per minute.

5. Biparietal size

The first screening study during pregnancy assesses this parameter depending on the period:

at 10 weeks - 14 mm
11 - 17 mm
screening for 12 weeks should show a result of at least 20 mm
at 13 weeks BPD is 26 mm on average.

According to the results of ultrasound of the 1st trimester, it is assessed whether there are markers of fetal anomalies. It is also analyzed to what period the baby's development corresponds. At the end, a conclusion is made whether it is necessary to conduct the next screening ultrasound in the second trimester.

You can ask to have a 1-trimester ultrasound video recorded. You also have every right to get a photo, that is, a printout of the image that is either the most successful (if everything is normal), or most clearly demonstrates the pathology found.

What are the norms of hormones determined by 1 screening

First trimester screening not only evaluates the results of ultrasound diagnostics. The second, no less important stage, by which it is judged whether the fetus has serious defects, is a hormonal (or biochemical) assessment (or a blood test in the 1st trimester). Both of these steps constitute genetic screening.

1. Chorionic gonadotropin

This is the hormone that stains the second strip on your home pregnancy test. If the first trimester screening reveals a decrease in its level, this indicates a pathology of the placenta or an increased risk of Edwards syndrome.

Elevated hCG at the first screening may indicate an increased risk of developing Down syndrome in the fetus. Although with twins, this hormone is also significantly increased.

The first screening during pregnancy: the rate of this hormone in the blood (ng / ml):

10 week: 25.80-181.60
11 week: 17.4-130.3
decoding of the perinatal study of the 1st trimester at 12 weeks relative to hCG shows the figure 13.4-128.5 is normal
at 13 weeks: 14.2-114.8.

2. Pregnancy Associated Protein A (PAPP-A)

This protein is normally produced by the placenta. Its concentration in the blood increases with the duration of pregnancy.

How to understand the data

The program, into which the data of ultrasound diagnostics of the first trimester, as well as the level of the above two hormones, are entered, calculates the analysis indicators. These are called "risks." In this case, the decoding of the results of screening for the 1st trimester is written in the form not in the level of hormones, but in such an indicator as "MoM". This is a coefficient that shows the deviation of the value for a given pregnant woman from a certain calculated median.

To calculate MoM, the indicator of a hormone is divided by the median value calculated for a given area for a given gestational age. MoM norms at the first screening are from 0.5 to 2.5 (with twins, triplets - up to 3.5). The ideal MoM value is close to "1".

Are there risks in research

Normally, the results of the 1st trimester diagnosis end with an assessment of the degree of risk, which is expressed as a fraction (for example, 1: 360 for Down's syndrome) for each syndrome. It is this fraction that reads like this: in 360 pregnancies with the same screening results, only 1 baby is born with Down's pathology.

Deciphering the norms of screening for the 1st trimester. If the child is healthy, the risk should be low and the screening test result should be described as “negative”. All numbers after the fraction must be large (more than 1: 380).

Poor first screening is characterized by a "high risk" entry in the conclusion, a level of 1: 250-1: 380, and the results of hormones are less than 0.5 or more than 2.5 median values.

If the 1st trimester screening is poor, you are asked to visit a geneticist who decides what to do:

schedule you to re-test in the second, then - screening for the 3rd trimester
offer (or even insist) on an invasive diagnosis (chorionic villus sampling, cordocentesis, amniocentesis), on the basis of which the question of whether this pregnancy should be prolonged will be decided.

What affects the results

As with any study, there are false positive results from the first perinatal study. So, for:

IVF: the results of hCG will be higher, PAPP - 10-15% lower, the indicators of the first screening ultrasound will increase the LHR
obesity of the expectant mother: in this case, the levels of all hormones increase, while with low body weight, on the contrary, they decrease
screening for 1 trimester for twins: the rate of results for such a pregnancy is not yet known. Therefore, risk assessment is difficult; only ultrasound diagnostics is possible
diabetes mellitus: the 1st screening will show a decrease in the level of hormones, which is not reliable for the interpretation of the result. In this case, pregnancy screening may be canceled.
amniocentesis: the rate of perinatal diagnosis is not known if the manipulation was carried out within the next week before donating blood. It is necessary to wait longer after the amniocentesis before undergoing the first perinatal screening of pregnant women.
the psychological state of the pregnant woman. Many people write: "I'm afraid of the first screening." It can also affect the result, and unpredictably.

Some features in pathology

The first screening of pregnancy for fetal pathology has some features that doctors of ultrasound diagnostics see. Consider perinatal screening of trisomies as the most common pathologies detected by this examination.

1. Down syndrome

in most fetuses, the nasal bone is not visible at 10-14 weeks
from 15 to 20 weeks, this bone is already visualized, but it is shorter than normal
smoothed out the contours of the face
with dopplerometry (in this case, it can be performed even in this period), reverse or other pathological blood flow in the venous duct is noted.

2. Edwards syndrome

tendency to decrease the heart rate
have an umbilical hernia (omphalocele)
no visible bones of the nose
instead of 2 arteries of the umbilical cord - one

3. Patau syndrome

almost everyone has heart palpitations
impaired development of the brain
the development of the fetus is slowed down (inconsistency of the lengths of the bones with the term)
violation of the development of some parts of the brain
umbilical hernia.

Where to study

Where is the 1st trimester screening done? Many perinatal centers, medical genetic consultations and private clinics are conducting this study. To choose where to get screened, see if there is a laboratory in or near the clinic. It is recommended to take it in such clinics and centers.

For example, in Moscow, the CIR has proven itself well: it conducts and screening of the 1st trimester can be done in this Center.

Ultrasound screening of the 1st trimester: the average price is 2,000 rubles. The cost of the first perinatal study (with the determination of hormones) is about 4000-4100 rubles.

How much does the first trimester screening cost by type of test: ultrasound - 2000 rubles, HCG determination - 780 rubles, analysis for PAPP-A - 950 rubles.