What week is screening done during the 1st trimester to get the most information about the baby?

Expectant mothers in vain rush to go for an examination as soon as they find out about their interesting situation. The 1st screening, consisting of a blood test and an ultrasound, is pointless to take place early.

But it cannot be postponed either, because this mandatory procedure evaluates the processes of intrauterine development.

In the first three months of pregnancy, it is necessary to undergo screening in order to detect serious pathologies without delay.

These include an anomaly of the germ of the future nervous system, Patau syndrome, hernia of the umbilical cord (intestine and liver are located outside the abdominal cavity - in the hernial sac), trisomy on the 21st (Down syndrome) or 18th chromosome (Edwards syndrome).

On ultrasound during the 1st trimester, the growth of the embryo is measured, determining its coccyx-parietal size, circumference and biparietal size of the head.

At the first screening, you can see if the right and left hemispheres are symmetrical relative to each other. At this time, the doctor will be able to see what structures have appeared in the brain.

The first screening involves measuring the length of the four main bones: thigh, lower leg, upper arm, and forearm.

The doctor checks where the internal organs (heart and stomach) are located, determines the size of the heart muscle and the veins and arteries coming from it.

Also on ultrasound in the first three months of pregnancy, the abdominal circumference of the embryo is measured.

Biochemical screening is aimed at determining plasma protein A and human chorionic gonadotropin.

Thanks to this study, the doctor learns about the presence of chromosomal abnormalities, about the possible risks and complications of pregnancy.

In the first trimester, the study should in no case be skipped by women who are married to a close relative, and those who have had several miscarriages.

The first screening is very important procedure for women who have been ill in the position of a viral or bacterial infection.

Women who have:

• previously had a frozen pregnancy;
• have relatives with genetic abnormalities;
• a child with Down syndrome or Edwards syndrome has already been born;
• age has reached the age of 35;
• was therapeutic therapy with drugs prohibited during pregnancy.

In any case, it is impossible to forget about visiting an uzist doctor, because every parent needs to make sure that the child is healthy.

Timeframes and features

The expectant mother can go for an ultrasound of the fetus and donate blood for analysis at the 10th week of pregnancy. But doctors urge to do this a little later - between 11 and 13 weeks.

It is at this time that it is possible to perform accurate measurements of the level of hormones and the collar zone of the fetus.

Deadline for inspection internal organs and extremities of the child at the 1st screening - 14 weeks of pregnancy.

It is better to come for an ultrasound at least at this time than even later, because doctors need to determine the time of birth and the degree of development of the child in time by its coccyx-parietal size.

The first examination for the expectant mother will begin with an ultrasound. There is no need to prepare for a transvaginal examination, but for a transabdominal ultrasound you will have to drink a large number of water (1 liter).

Filling the bladder before examination at 10 - 14 weeks - required condition otherwise the ultrasound will not pass through the abdominal wall.

Transabdominal ultrasound is done through the abdominal wall. A woman needs to lie down for some time, exposing her stomach and inguinal region.

The doctor will guide the skin with a special sensor treated with a gel to improve gliding.

To conduct a transvaginal study at 10 - 14 weeks of pregnancy, a woman must completely free herself from clothes below the waist, lie down and bend her legs.

The doctor will insert a thin probe into the vagina, on which a special condom will be put on, and evaluate the development of the fetus in the uterus.

This will not cause pain, but, perhaps, after the procedure, spotting spotting will be observed.

The next time, for the second screening, no preparation is required, because the ultrasound will help to penetrate the accumulated amniotic fluid.

You will always have to prepare for blood sampling to determine the ratio of hormones. A few days before the analysis at 10-14 weeks, the pregnant woman must give up sweets, meat and fish.

Usually, blood is taken from a vein in the morning. You can't eat breakfast right before. You can eat last time 4 hours before the procedure.

Ultrasound indicators in the 1st trimester

After an ultrasound of the first trimester, a woman wants to understand the information written in the examination protocol.

After all, the mothers themselves do not know how much the coccyx-parietal and biparietal dimensions, the thickness of the collar space and the heart rate should be.

The thickness of the collar space (TVP) at the 10th week of pregnancy is normally 1.5 - 2.2 mm. At 11 and 12 weeks, this figure increases to at least 1.6 mm.

At the 13th week of the 1st trimester, it is already 1.7 - 2.7 mm. If the value of TVP is higher than the established norm, then the child may have genetic abnormalities.

To determine the BDP indicator, you need to know exactly how many days have passed since the day the child was conceived.

It is important to assess the thickness of the collar space during the first trimester, since then the measurement of this indicator will not be available.

For a period of 10-11 weeks, the nasal bone should be clearly visualized on the screen of the ultrasound equipment. A little later, the doctor already has the opportunity to measure it. normal size nasal bone - from 3 mm. This indicator is noted in almost 100% of embryos.

When the first screening is done, it is determined how many times per minute the baby's heart beats. At week 10, the organ of the embryo should make more than 161 beats per minute.

The limit is 179 hits. A week later, the baby's heart should beat less frequently, between 153 and 177 beats per minute.

The normal rate for the 12th week is 150 - 174 bpm, and for the 13th - 147 - 171 bpm.

Too frequent heartbeat of the child may indicate the presence of an anomaly of the 21st pair of chromosomes, that is, Down syndrome.

During the first screening, the doctor necessarily determines the size of the maxillary bone in the embryo. If this indicator is less than normal, the child should be suspected of a genetic disease - trisomy.

Later than the 11th week of pregnancy, it becomes possible to examine the bladder of the fetus. An enlarged organ is a clear sign of a child with Down syndrome.

1st trimester blood test results

Biochemical screening in the first three months of pregnancy reveals how much hCG and PAPP-A are contained in the blood serum. But the most informative than hCG is the indicator of β-hCG.

The fact is that the level of hCG can change not only because of the woman's pregnancy. Sometimes hormonal imbalances and the use of certain medications can affect its value.

The level of β-hCG depends solely on the duration of the woman's pregnancy. At week 10, its value should fluctuate between 25.8 and 181.6 ng / ml, at week 11 - between 17.4 and 130.4 ng / ml.

Within 12 weeks, this indicator is normally 13.4 - 128.5 ng / ml. When the 13th week of pregnancy ends, the level of β-hCG can reach 14.2 - 114.7 ng / ml.

The value of β-hCG may indicate not only the presence of deviations in the genome in the fetus, but also the incorrect course of pregnancy and the deterioration of the woman's condition.

If biochemical screening showed that a woman has an elevated hormone level, then this may indicate:

• multiple pregnancy;
• acute toxicosis;
• down syndrome;
• diabetes mellitus;
• blistering.

Also, the reason may be in taking certain drugs and the presence of cancer in a pregnant woman.

Low levels of β-hCG signal other problems:

• Edwards syndrome in the fetus;
• pregnancy in the fallopian tube;
• frozen pregnancy;
• risk of spontaneous abortion.

During the 1st trimester in a woman, it is very important to determine the level of PAPP protein. It is produced by the placenta and gradually increases throughout pregnancy.

When is celebrated low level PAPP-A, the doctor suspects a chromosomal abnormality in the fetus. The most common are Down syndrome and Edwards syndrome.

But, if the screening showed a very high level of PAPP-A, then the pregnancy is frozen or it may terminate unexpectedly.

It is better to determine the level of PAPP-A before the 14th week. It is not advisable to do this later, since then it will not be possible to identify Down syndrome by the content of this protein.

In order to find out important data about the process of intrauterine development of a child in time, take into account all the risks and identify anomalies, it is necessary to do an ultrasound scan and a blood test on time.

According to the rules, a woman must undergo all examinations of the first trimester in the period from 10 to 14 weeks.

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

First trimester screening consists of ultrasound and blood test

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

This method of verification even reveals complications in pregnancy, which the expectant mother might not have been aware of due to the absence of symptoms, good health, etc. This study is not always made pregnant, often other groups of people undergo it.

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

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

How is the study carried out and for how long?

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

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

The procedure consists of two stages:

1. Diagnostics by ultrasound;
2. Study of blood biochemistry.

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

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

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

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

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

What can be learned from screening?

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

The specialist examines the following indicators:

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

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

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

3D ultrasound examination is now possible

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

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

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

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

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

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

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

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

Rules for preparing for the study

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

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

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

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

Screening for the first trimester of pregnancy

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

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

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

Who is referred for 1st trimester screening?

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

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

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

How the study is done

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

There are machines for home ultrasound

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

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

1st trimester screening price

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

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

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

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

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

PAPP-A - what is it?

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

Human chorionic gonadotropin (hCG)

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

An increase in the rate may indicate:

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

The deficiency indicates:

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

Remember, only a specialist can correctly determine the risk.

What is KTP during pregnancy on ultrasound

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

KTR norms

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

But if the indicator is lower, then:

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

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

Fetal BDP (biparietal size)

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

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

Collar space thickness (TVP)

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

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

Signs of Down syndrome, as well as Edwards and Patau

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

Nasal bone at 12 weeks, table of norms

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

Heart rate (HR)

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

What can distort the result

False positive results occur in such cases:

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

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

What is risk and how is it calculated?

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

What if I am at high risk?

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

How to confirm or refute the results of screening?

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

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

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

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

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

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

Third screening during pregnancy

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

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

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

Timing of the third screening during pregnancy

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

Where to take the study

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

The first trimester of pregnancy is considered thirteen weeks after the last menstrual period. As a rule, the first visit to the doctor, at which they begin to discuss prenatal care, the expectant mother makes between the 8th and 10th week of pregnancy. During the first trimester screening, various tests and checks are done to help assess the development and health of the fetus and mother. Perinatal screening during pregnancy allows you to identify various pathologies, including:

• Down Syndrome,


• Edwards Syndrome,


• heart disease,


• neural tube defects and so on.

Screening of the first trimester of pregnancy begins with a general examination. Having studied the detailed medical history pregnant woman, the doctor conducts a complete physical examination, during which he receives information about weight and blood pressure. Also, at the screening of the first trimester, a urinalysis, a general blood test, a blood type are tested, and an analysis is done for HIV, hepatitis and syphilis.

Screening for the first trimester of pregnancy also includes genetic testing, which allows you to understand if the expectant mother or her partner has any. Tests are being done for cystic fibrosis, sickle cell anemia, thalassemia, and Tay-Sachs disease. At this stage, the doctor will usually tell the pregnant woman about the benefits and risks of genetic testing and screening in general, and what each of the tests means for the fetus.

Between 10 and 13 weeks of gestation, a chorionic biopsy is usually performed. The purpose of this procedure is to search for genetic disorders and chromosomal abnormalities. It looks like this: a needle or catheter is inserted through the anterior abdominal wall of a pregnant woman under ultrasound guidance to take a tissue sample from the placenta. This operation is associated with certain risks: about 1 in 100.

In addition, when screening the first trimester of pregnancy, ultrasound is also done. This is necessary in order to assess the size of the fetus, to clarify its age, and also to see the location in the uterus. By the way, if a pregnant woman suffers from vaginal bleeding, ultrasound can be used to determine their cause.

Second trimester screening

Screening of the second trimester of pregnancy is carried out between the 15th and 20th weeks of the term. During this period, obstetricians and gynecologists usually recommend that a pregnant woman do four blood tests, which are all made from one sample. These tests are designed to identify possible chromosomal abnormalities, to detect any damage in the body of the fetus, either in the spine or in the abdomen. In addition, second-trimester screening can predict 80% of the chance of having a baby with Down syndrome.

Many women, especially those under the age of 35, choose to have both their second trimester screening and first trimester screening. They explain their decision by saying that they want to quickly move on to amniocentesis (an invasive procedure in which amniotic fluid is taken for analysis).

Although Down syndrome and some other chromosomal abnormalities can no longer be cured, screening during the second trimester of pregnancy can detect possible treatable neural tube defects, such as spina bifida. The chance of detecting such defects in second trimester screening is quite high, about 80 percent. When this conclusion is confirmed by an ultrasound test, a decision can be made to perform a caesarean section, which will avoid spinal injuries. And the splitting of the vertebral arches closes shortly after childbirth.

What is biochemical screening?

Biochemical screening is primarily blood tests. Initial blood tests, which are done almost at the very beginning of pregnancy, allow, for example, to detect signs of rubella or hepatitis B, and determine how high the risk of fetal infection with these diseases is. Tests for some STDs, including HIV and syphilis, are also part of biochemical screening, as all of these diseases pose a serious risk to the unborn child. In biochemical screening, the doctor also determines the blood type of a pregnant woman, whether she is Rh-positive or negative. If the expectant mother is Rh negative and the baby is Rh positive, treatment may be needed to prevent the mother's body from producing antibodies to the baby's blood. Biochemical screening also allows you to determine the level of pregnancy hormones. Later in pregnancy, a blood test allows the doctor to check the likelihood of gestational diabetes.

Another important part of biochemical screening during pregnancy is a urinalysis, which shows protein and sugar levels. Both can indicate potential problems. Protein levels can indicate that the mother-to-be has a urinary tract infection, kidney disease, or preeclampsia. And elevated sugar levels sometimes indicate diabetes. Either way, treatment is required.

Screening: Risks

Like any medical procedure, pregnancy screening requires some intervention in the body. What are the risks of screening?

The biggest fear associated with screening occurs in the expectant mother about possible risk fetal loss. This risk is small, but some prenatal testing procedures, such as amniocentesis or chorionic biopsy, can increase it. In a chorionic biopsy, the doctor removes a small amount of tissue from the placenta to check the chromosomes. With this screening procedure, the risk of pregnancy loss is less than 1 percent. And during an amniocentesis, the doctor inserts a thin needle into the abdomen and withdraws a small amount amniotic fluid for analysis. With this type of screening, the risk of miscarriage is about one in 200.

Screening of the 1st trimester is included in the general set of examinations during the gestation period to assess the health of the child and possible threats to gestation. Screenings are a common research method that applies not only to pregnant women: a referral for screening studies is also prescribed for newborns, as well as any population groups included in the risk group for developing any diseases, abnormalities, dysfunctions.

Screening studies allow you to determine the likely possibility of the presence of pathology. In the first trimester of pregnancy, screening combines an ultrasound examination and analysis of blood parameters, while the results are deciphered exclusively in a comprehensive analysis of both types of research.

First screening during pregnancy: period and timing of the study

During pregnancy, women are offered to undergo three screenings to identify and correct in time possible deviations during pregnancy or fetal development.

1 screening is carried out in the first trimester. Terms of pregnancy in classic version are established on the basis of obstetric calculation, where the first day of the gestational period is the date of the beginning of the last menstruation before the onset of pregnancy. With the calendar method for determining the gestational age, experts start from the day of conception. However, since it is difficult to determine this date during physiological conception (the day of ovulation and the day of the fusion of the egg and sperm may differ by 3-5 days), it is recommended to adhere to an obstetric technique focused on the date of the last menstruation.

With a long menstrual cycle, the specialist can make changes to the screening dates, however, on average, the first screening study is carried out between 11 and 14 weeks of gestational age, limiting the upper limit of the period to 13 weeks and 6 days from the date of the start of the last menstrual bleeding.

Why was this period chosen for the first screening? At 12 obstetric weeks, the border between the embryonic and fetal or fetal developmental period passes: the unborn baby moves from the stage of the embryo to the fetus. The presence of formed structures and changes in the body allow you to appropriate the future baby new status at the perinatal stage of development.

Also, this period is the minimum at which it is possible to identify the most common, although quite rare, deviations, as well as the reactions of the mother's body to the development of a new life.

Screening - voluntary research or obligation?

Since the early diagnosis of probable deviations allows you to quickly and effectively help expectant mother to correct possible negative consequences, screening studies during the gestation period are strongly recommended for all pregnant women, regardless of age, health status and the presence of healthy children. Deviations recorded during the study may occur spontaneously without correlation with the health of parents, relatives and lifestyle.

Despite the fact that the screening study is carried out in the direction of a gynecologist, screening can be waived. This procedure is voluntary, although it is recommended by the Ministry of Health as part of the medical support for pregnancy in any woman.

If screening is refused for one reason or another, it must be remembered that this study is useful for everyone, and in particular for certain categories of expectant mothers. The high-risk group includes:

• future mothers over the age of 35, regardless of previous experience of pregnancy and childbirth. This recommendation is associated with an increase in the number of probable chromosomal disorders in the beginning of the aging process;
• women who have been diagnosed with a condition that threatens spontaneous miscarriage or miscarriage, missed, non-developing pregnancy;
• a history of infectious diseases (including influenza, SARS during the first trimester);
• parents with genetic disorders, women who had a high risk of genetic abnormalities during previous pregnancies, the presence of pathologies or have children born with chromosomal abnormalities;
• pregnant women who are forced to take medications that are limited or prohibited during the gestation period or immediately before it, some types of vaccination and medical procedures that preceded pregnancy in the short term;
• women whose pregnancy occurred as a result of a closely related relationship;
• women with addictions: alcohol, drug addiction, etc.

A screening study does not pose a risk to the fetus or mother, so the refusal of a diagnosis that can reveal easily correctable this period deviations are at least unreasonable.

The study is carried out in public clinics free of charge. You can choose to undergo screening at any other clinic, if necessary, it is possible to re-conduct both a complete study and one of its stages, if the gestational age allows.

What is included in the first perinatal screening?

Screening in the first trimester of pregnancy is limited to an ultrasound examination of the condition of the fetus and uterus of a woman, as well as a biochemical study of the blood of a pregnant woman, in which the level of the corresponding hormones and the presence of certain markers are determined.

The size of the fetus, the characteristics of the development of its body parts, bones, the presence of certain parts of the circulatory system, in combination with the results of a blood test, make it possible to confirm the correct development of the child and the reaction of the mother's body, or to suspect the possibility of some deviations.

How to prepare for the first screening?

Ultrasound examination of the fetus and uterus can be carried out by two methods: using an apparatus with a transvaginal sensor or a transabdominal method of external examination through the surface of the peritoneum.

In the first case, preparation for the study consists in emptying the bladder immediately before the ultrasound, in the second, before the study, it is necessary to fill the bladder, which will create the necessary darkening and contrast. Filling the bladder should be done approximately 30 minutes before the start of the study, the required volume of fluid is from 0.5 to 0.7 liters. It is preferable to drink non-carbonated water and not go to the toilet, starting from 4 hours before the time of visiting a specialist until the end of the ultrasound.

During the procedure itself, the position of the fetus is an important factor. If the child lies in such a way that it is difficult to calculate the exact dimensions of some parts of the body, then the expectant mother may be asked to walk, bend over, strain and relax her stomach, imitate coughing, etc. At the same time, it is sometimes possible to determine the sex of the unborn child, however, for for a more accurate result, it is better to wait for the second ultrasound for a period above 20 weeks.

Blood biochemistry during screening of the first trimester should be carried out strictly after ultrasound. The blood formula in the mother's body during the gestation period changes daily, and without a correlation with the date of the ultrasound, the specialist will not be able to correctly interpret the analysis data.

For the most reliable results of a biochemical blood test, it is necessary to exclude all factors that may affect the functioning of various organs. Thus, preparation for the second stage of screening includes:

• exclusion from the diet of food-potential allergens for all women (cocoa products, nuts, shellfish, citrus fruits, out-of-season vegetables and fruits) and identified allergens for pregnant women with a history of allergic reactions. It is necessary to notify the specialist about the presence of an allergy at the time of screening or shortly before it, this will allow a more accurate assessment of the results of the analysis. It is not worth talking about the need not to take alcohol during pregnancy, but this rule is especially important before screening and applies even to small doses of alcohol on holidays;
• the last meal should be 12 hours before blood sampling for research, in the evening of the previous day. After the rise and before the analysis, you can not drink;
• just before blood sampling, you need to sit for 15-20 minutes, avoid stress, physical activity (jogging after the bus, climbing a long staircase, etc.).

Failure to comply with the above rules may lead to distortions in the test results, which may be incorrectly interpreted as a deviation in the development of the fetus or the course of pregnancy. Such unnecessary risks must be avoided.

Fetal parameters assessed by ultrasound at first trimester screening

In the process of ultrasound examination, the specialist evaluates the size of the fetus according to various indicators, as well as some important parameters of the child’s body at this period of development, the developmental features and condition of the placenta and uterus of the mother.

In the results of ultrasound during the first screening, you can see the following designations:

• KTP, or the length of the fetus from the crown of the head to the coccyx: this is how the process of intrauterine development denotes the “growth” of the child, since the most characteristic position of the fetus is with legs bent and drawn to the chest, especially on later dates, does not allow to determine the length of the whole body. Full "height" can be roughly estimated from the length of the femur bone, which, like the length of the bones of the shoulder and forearm, is an important indicator of fetal development;
• OG is an indicator of the size of the fetal head, measured in circumference (calculated based on the diameter);
• BDP is an indicator of the bioparental size of the head between the parietal bones. This indicator reflects both the development of the head structures of the fetus, and, in the later stages, allows us to make assumptions about the preferred method of delivery of the mother. With a large volume of the skull and a narrowed pelvis, most likely, a caesarean section will be offered. The distance from the forehead to the back of the child's head is also measured;
• TVP - an indicator of the thickness of the collar space or neck fold fetus, evaluated only in the first trimester. By week 16, this formation is transformed into new organs, and during the first screening for this indicator, in combination with blood markers, the absence or increased likelihood of chromosomal disorders is diagnosed;
• the thickness of the nasal bone as a probable indicator of the presence of genetic abnormalities is measured by ultrasound at 12-13 weeks, ultrasound at 11 obstetric weeks in most cases only allows you to notice its presence and the beginning of formation;
• structural features of the brain, skull bones: this indicator describes how symmetrically and in accordance with the norm the cranium and brain tissues of the fetus develop;
• Heart rate, an indicator of heart rate or heartbeat, is estimated according to the age norm. Also, when examining the heart, if possible, the specialist studies the size, structural sections of the heart muscle. The localization of the heart, stomach, large arteries and veins is also examined;
• localization of the chorion (placenta), the thickness of this organ. In later studies, the presence and number of calcifications will also be studied - inclusions indicating the physiological aging of the placenta;
• the number of umbilical vessels;
• the volume and condition of the amniotic fluid;
• characteristics of the tone of the uterus and cervical pharynx.

Average values ​​of the main parameters in accordance with the weeks of pregnancy:

Interpretation of the results of biochemical screening of the first trimester

The main indicators that specialists are guided by when deciphering the results of a biochemical blood test at this stage are the level of human chorionic gonadotropin, a marker hormone hCG pregnancy, and plasma protein A, or PAPP-A.

The fetal membrane (chorion), which begins to form immediately after the fertilization of the egg by the sperm, produces chorionic gonadotropin on the very first day. However, the reference values ​​that allow determining pregnancy, this hormone reaches no earlier than after 2 weeks. Highly sensitive express tests and a blood test for pregnancy determine the presence of this particular component.

In the first weeks of pregnancy, the level of chorionic gonadotropin increases, doubling the rates almost daily. The level of this hormone reaches its peak concentration by 11-12 weeks, then there is a decrease and fixation at insignificant levels.
High hCG in relation to the norm may indicate the following abnormalities and / or physiological conditions:

• multiple pregnancy, in which the hormone is produced by several chorions;
• endocrinological diseases of the mother (diabetes mellitus) in history or developing against the background of gestation;
• manifestation of severe toxicosis of the first trimester;
• chromosomal disorder - Down syndrome in the fetus.

Reduced relative to reference values, the level of human chorionic gonadotropin (hCG) may indicate the following disorders:

• placental insufficiency;
• the presence of an ectopic pregnancy;
• increased risk of miscarriage, spontaneous abortion;
• genetic disorder - Edwards syndrome in the fetus.

When assessing the level of PAPP-A, only low values ​​matter. They may indicate a threatened abortion due to an inadequate response. immune system mother or insufficient functioning of the placenta, as well as some chromosomal abnormalities in the fetus.

Comprehensive interpretation of screening results

The results of the screening of the first trimester after a full assessment of all indicators will contain the following data:

• risks of deviations associated with the age of the mother;
• assessment and interpretation of biochemical parameters of the mother's blood;
• the likelihood of the presence or occurrence of various diseases;
• MoM value.

Based on the results of an ultrasound examination and a biochemical blood test, specialists bring the data together and assign the so-called MoM index (multiple of median). This coefficient is formed on the basis of variable indicators typical for the range of results of studies of healthy women with normal course pregnancy and early developing fetus.

The norms for the first screening are from 0.5 to 2.5 units for a singleton pregnancy, and up to 3.5 if two or more babies are expected.
After calculating the IOM, the results are entered into the program, which takes into account all the factors that affect the health of the mother and child and the course of pregnancy: age, height-to-weight ratio, certain diseases (in particular, diabetes mellitus), the presence of bad habits(tobacco smoking), number of gestations, physiological or extracorporeal method of conception, etc.

Based on the evaluation of all data, the program provides a probable risk of genetic abnormalities in the fetus. The result is presented as a ratio of 1:1000 in relation to several genetic diseases, expressing the risks of this syndrome in each specific case. An index of 1:380 or more is considered positive for a low risk of violations, an index below 1:380 means an increase in risk.

But this indicator is not a final diagnosis, but an assessment of probabilities. So, if the conclusion of a specialist contains an index of 1:70 to Down syndrome, this means that only 1 out of 70 women with similar results has a child with developmental disabilities. In 69, pregnancy proceeds without deviations and ends with the birth of a healthy child.

The following factors influence the distortion of the results:

• non-compliance with the rules of preparation for biochemical analysis;
• outdated ultrasound equipment;
• in vitro fertilization;
• endocrinological disorders ( diabetes mellitus both types)
• multiple pregnancy;
• increased body mass index of the mother (overweight).

What to do if screening results are disappointing?

Many women are afraid to pass the “first exam” in the life of the fetus, afraid of both hearing negative news and hasty appointments and even pressure to terminate the pregnancy. If there are doubts about the results, you can undergo additional screening, following the rules for preparing and alternating ultrasound and biochemistry, and assess the condition and results in the complex.

In fact, “high risk” is diagnosed at rates from 1:250 to 1:380 for any syndrome, which means a slightly increased, but not necessarily, probability of a child having genetic abnormalities. With such indicators, it is recommended to conduct healthy lifestyle life, be regularly observed by a gynecologist and undergo a consultation with a geneticist.

In some cases, a geneticist may offer to undergo an additional examination for accurate diagnosis (chorionic villus biopsy, amniocentesis, cordocentesis), on the basis of which recommendations for parents will be made.

Today in Russia (at least in many large cities) screenings are recommended for every pregnant woman. This year I was pleasantly surprised to learn that now in Moscow they are not sent for this procedure without prior consent for screening ... By the way, in any case, I was determined to write a refusal. Why? Is it necessary to do screening?

In my first pregnancy, I found out what this incomprehensible word means only after the results were announced. Without suspecting anything, at 12 weeks I donated blood from a vein, did an ultrasound ... And after a couple of weeks, a call came from my “ antenatal clinic". The nurse insistently suggested that I come to an unscheduled appointment with a gynecologist tomorrow, as the results of my tests appeared ... They did not disclose details over the phone, and I came to my doctor with apprehension, not knowing what to think about.

“Your screening is bad,” the doctor announced to me and gave me a piece of paper with some numbers and a bold inscription: “Diagnosis: high risk of Down Syndrome.” Then the gynecologist began to say with a smile that there was no need for me to worry, I just needed to go for a consultation with a geneticist and agree to an additional analysis - amniocentesis.

I soon learned that amniocentesis, which most doctors so strongly recommend, is a rather dangerous test. For this analysis, you need to pierce the bubble and take it for research. amniotic fluid. According to various sources, there is a 1-3% chance of miscarriage, especially for girls with a negative Rh factor (that's me). There is still a chance that the doctor will not be able to conduct an analysis. And that as a result you will learn nothing. And in any case, the answer is "Isn't Down there?" will come to you in a few weeks. Moreover, if doctors find out that you have a child with Down Syndrome, they will simply suggest an abortion. There is no cure for this diagnosis. And you can't influence anything. You can only kill your baby at 16 weeks pregnant. Are you ready for this?

I think that before you decide on an amniocentesis, you should decide whether you are ready for an abortion. If abortion is a rather ordinary phenomenon for you, then yes, you are welcome. And if not, are you ready to risk a healthy child for the sake of some tests that still won’t change anything?

Ideally, this issue should be resolved prior to screening. Therefore, in the second pregnancy, I did not do screening. What for?

Of course, all people are different, everyone needs to decide for themselves whether to do screening. Here I will give only my view on this issue.

First, screening is not informative. He gives like false positive results, and false negatives. Go to the forum of parents of children with Down Syndrome (I spent quite a lot of time there). Many of them got good results from this test... But a shock awaited them in the delivery room. That is, screening does not guarantee that your baby does not have genetic disorders!

Secondly, after poor screening, only amniocentesis can be done. And if you are not ready for an amniocentesis, why should you wind your nerves in vain?

Thirdly, if you are destined to have a child with Down Syndrome, is it necessary to know about this before the birth itself? Maybe it's better to spend the pregnancy calmly, so that it has a better effect on the development of the baby? Indeed, in such a situation, a woman can not change anything, nothing!

It is also worth remembering that children with such disabilities are sent to us very, very rarely. They are sent only when we need to go through especially tough lessons. Almost all women with a diagnosis of "high risk of diabetes" give birth to healthy children. And if God suddenly gives someone the hardest test, it means that he knows that we can cope with it, it means that only in this way can we understand something very important for ourselves. Read the forum I mentioned above. Many parents accepted their children for who they are, despite the fact that this is heroism. Many parents have learned to live with it, have learned to rejoice, despite the child's diagnosis. And everyone tries to cheer up the other... There I read one deep thought... It's your choice - to kill yourself and consider that your whole life has collapsed, or learn to live happy and rejoice. This is our choice. Sounds trite, if you do not consider what kind of person wrote it. So if they proudly post photos of their kids, admire their successes and assure "newcomers" that everything is not as scary as they think ... What right do we, mothers of healthy children, have to complain?

And if someone needs to have only healthy child, he does not agree to accept any other ... It is better to take the baby from the orphanage. Since giving birth to our children, we always take a certain risk - it can be a disabled person, a child without legs, or a person with Down Syndrome ... But this always happens only by the will of God. Do you really think that He can just take it and make a mistake?