How many blood tests are done, and what are the nuances of the study. First screening during pregnancy: when and how they do it, deciphering the results, norms and deviations How much screening is done in time

In obstetrics, pregnancy management involves multiple examinations of the pregnant woman and the fetus. How many times is screening done? Within 9 months, a woman needs to undergo a general examination three times at different times. It is carried out to assess the basic physiological and anatomical characteristics of the fetus and to determine the likely pathologies.

The first trimester of pregnancy lasts 14 weeks, by the end of this period, the first scheduled examination is scheduled, consisting of the obligatory first ultrasound of the fetus and various laboratory blood tests.

Order No. 457 Min. Healthcare R.F. from 2000 states that screening tests should be carried out for all pregnant women. Every woman has the opportunity to file a waiver. However, such an act can only talk about the illiteracy of the future mother and indicate a negligent attitude towards her baby.

How many risk factors are there that are considered mandatory prenatal screening? The main reason for the examination is:

age criterion: 35+;
the end of previous pregnancies with a miscarriage or fetal freezing;
professional harm;
diagnosis of chromosomal abnormalities in the fetus in a previous pregnancy or the birth of a child with intrauterine malformations;
diseases of an infectious nature, transferred at the beginning of pregnancy;
taking drugs prohibited for pregnant women;
alcoholism, drug addiction;
diseases transmitted by heredity, both in the mother's family and in the family of the child's father;
close family ties between the parents of the baby.

Prenatal screening is very important for those women who have genetic diseases in their family or who have had a baby with chromosomal abnormalities. Screening will make it possible to diagnose pathologies of the current pregnancy, if necessary, to prescribe its termination for medical reasons

Conducting a prenatal examination

When is the examination carried out? Primary prenatal screening is done at the end of the first trimester. The timing is due to the fact that by this time most of the systems and organs of the unborn child have already formed, and the diagnostician has the opportunity to assess the development of the fetus, to identify pathologies in a timely manner. At 13 weeks, ultrasound diagnostics allows you to determine neural tube defects and genetic pathologies in the embryo.

Ultrasound diagnostics as 1 stage of screening

What tests does the first trimester screening include? Screening consists of several types of mandatory diagnostic procedures and tests. Fetal ultrasound is the main diagnostic procedure in the first trimester. It is carried out in two ways: transvaginal, that is, the sensor is inserted into the vagina, or abdominal, that is, through the anterior abdominal wall.

Ultrasound screening of the 1st trimester allows you to determine the anatomical features of the child, the presence of all organs, assess their location and development. Also, the main dimensional fetometric indicators, characteristics of the correct development of the fetus are assessed, the cervical fold, head circumference, biparietal diameter, etc. are measured. The size of the coccygeal-parietal size and, accordingly, the approximate growth of the child at this stage of development are necessarily determined. With the help of prenatal ultrasound diagnostics, the quality of the placental-umbilical cord blood flow is assessed, the work of the heart muscle is characterized. Including determine the thickness of the collar space in the fetus, the deviation of this indicator from normal values may indicate a high probability of developing chromosomal pathologies.

The first ultrasound study is indispensable in the management of pregnancy, because it gives the doctor the opportunity to take the first fetometric indicators, determine the level of fetal development, its compliance with the gestational age

Biochemical blood test, as stage 2 of screening

Biochemical blood tests are carried out in laboratory conditions. With the help of biochemical blood testing, carried out at 13 weeks, the level of the PAPP-A protein and the hCG hormone is established. This study is also called "double test".

The main hormone that begins to form after fertilization of the egg is human chorionic gonadotropin. When the level of the hormone hCG is low, this indicates that there is a placental pathology. The content of the hormone in the blood above the norm indicates fetal chromosomal abnormalities, or indicates a multiple pregnancy.

The level of plasma protein in a woman's blood can also indicate various abnormalities in the development of the embryo. When there is a significant decrease in the PAPP-A index, this indicates possible chromosomal abnormalities and other congenital genetic defects.

If the results of the first prenatal screening reveal a high probability of the existence of the described pathological conditions, additional diagnostic procedures are mandatory. The expectant mother is sent to the procedure for studying the properties of amniotic fluid - amniocentesis. The technique makes it possible to determine the presence of chromosomal pathologies and some genes. Chorionobiopsy is also done, i.e. a biopsy of the chorionic villi is performed. To carry out the test, cells that form the placenta are taken, and with their help, intrauterine and hereditary diseases are determined.

Preparatory stage of screening

The first screening study needs a preliminary preparatory stage. Prenatal examination at other stages of pregnancy does not require as careful preparation and is much easier.

What foods should not be consumed before the first screening? The day before research events, it is recommended to limit the consumption of foods that are potential allergens. These are chocolate, citrus fruits, seafood, individual intolerance products. Doctors advise against eating fried and fatty foods.

The first prenatal ultrasound is usually done with a transvaginal method. This diagnostic technique does not require special training. If, according to the indications, an abdominal examination is prescribed - an ultrasound scan performed through the skin of the abdomen - then it is necessary to drink a certain amount of pure water without gas in advance to completely fill the bladder (about 500 ml.).

Preparation for a biochemical blood test is quite simple. Screening is done in the morning on an empty stomach, so you should come to the laboratory without having breakfast. In addition, it is recommended to carry out standard hygiene measures before examinations without using perfumed cosmetic and hygiene products.

Normal test scores

At the first prenatal screening, a number of characteristics are determined and special attention is paid to their compliance with generally accepted standard norms:

With the help of ultrasound examination, the thickness of the collar space (TVP) is assessed.
The size of the nasal bone. This indicator, as well as the TVP value, allows for timely diagnosis of Down's syndrome. Until 11 weeks, it is still impossible to assess this anatomical characteristic, and at 13 weeks the length of the nasal bone should be at least 3 mm.
The characteristic, depending on the degree of development of the fetus, is the heart rate (HR). The dependence of the heart rate on the week of pregnancy is shown in the table below.
Also, ultrasound determines the value of the coccygeal-parietal size (CTE) and calculates the value of the biparietal size (BPD) of the child's head.

At the first ultrasound, the doctor must check for the presence of the nasal bone, calculate the thickness of the collar zone, and also make other fetometric measurements. All this complex of research and standards allows you to identify genetic abnormalities and developmental delays in the early stages.

The normative values of the indicators described above are presented in the summary table:

Week of pregnancy	TVP, mm	CTE, mm	Heart rate, beats per minute	BPR, mm
10	1,5 - 2,2	31 – 41	161 – 179	14
11	1,6 - 2,4	42 – 49	153 – 177	17
12	1,6 - 2,5	52 – 62	150 – 174	20
13	1,7 - 2,7	63 – 74	147 – 171	26

Screening of the first trimester of pregnancy includes a mandatory biochemical determination of the value of the hCG hormone. Normal values of this indicator in the female body correspond to the following values:

In addition to the above indicators, at the first prenatal screening, based on ultrasound data, it is imperative to assess the degree of development of the systems and organs of the unborn child. Using laboratory blood test methods, the content of glucose and protein A is determined.

Possible pathological conditions detected by examinations

With the help of ultrasound diagnostics performed in the first trimester of pregnancy, you can get important information about the possible development of chromosomal abnormalities.

Ultrasound determines the likelihood of the existence of Down syndrome, de Lange, Patau syndrome, Edwards syndrome, abnormalities in the formation of the nervous system, the appearance of an umbilical hernia and such a chromosomal abnormality as triplodia.

Decryption of screening data

When decoding the data obtained during an ultrasound examination and in a blood test, the doctor compares the results with standard normal values and calculates the probability of possible deviations. For this, the specialist determines the coefficients that show the discrepancy between the obtained data and some standard values. Usually, the resulting coefficient is denoted by the abbreviation MoM:

The normal MoM value for the first 12-14 weeks ranges from 0.5 to 2.5. The best is considered to be a MoM equal to 1.
The MoM value calculated for the hCG index below 0.5 indicates a high risk of Edwards syndrome. MoM above 2.5 is considered a sign of the development of Down syndrome.

Based on the results of the examinations, the general coefficient of the likelihood of the existence of serious genetic pathologies is calculated. In the event that the value of the generalized coefficient at 13 weeks ranges from 1: 251 to 1: 399, such a test result is considered bad, and according to the content of hormones, negative indicators are considered to be values of the coefficient below 0.5 and more than 2.5.

The development of two embryos, an overweight woman, diabetes mellitus, or other diseases of the endocrine system can affect the screening results, here many characteristics are allowed to deviate from the standard values. Sometimes even the psychological state affects the reliability of the data obtained during the research.

Unwanted screening results should not be cause for serious disappointment. No matter how high the risk of developing pathology is, there is an equally high probability of having a healthy child.

This testing is performed at the beginning of pregnancy to identify possible genetic abnormalities in the fetus. The first screening includes a blood test and an ultrasound examination. Only in combination do they give an accurate result. How to prepare for the procedure, to whom is it shown, and can you refuse it?

What is pregnancy screening

This is an extremely important examination carried out when carrying a baby. It allows you to assess the condition and development of an unborn baby. When prescribing screening, the doctor takes into account the characteristics of the mother's body (weight, height, bad habits, chronic diseases), which may affect the test results.

With ultrasound, the doctor examines the development of the fetus's physique and determines if there are any pathologies. If violations are found, treatment can be started on time.

How long does it take for the first screening

Patients are interested in when the 1st screening is done, and if there is a time frame that allows you to postpone or speed up testing. The timing is set by the gynecologist leading the pregnancy. Often he is appointed from 10 to 13 weeks after conception... Despite the short duration of pregnancy, the tests accurately show the presence of chromosomal abnormalities in the fetus.

Be sure to screen women at risk by 13 weeks:

have reached 35 years of age;
under the age of 18;
having genetic diseases in the family;
survivors of a spontaneous abortion before;
who gave birth to children with genetic disorders;
sick with an infectious disease after conception;
who conceived a child from a relative.

Screening is prescribed for women who have had viral diseases in the first trimester. Often, not knowing what is in the position, the pregnant woman is treated with conventional drugs, which negatively affect the development of the embryo.

What should I show

Thanks to the first screening, the expectant mother and the doctor will know exactly how the baby is developing and whether he is healthy.

The biochemical analysis of the 1st screening during pregnancy has certain indicators:

HCG rate- detects Edwards syndrome when the indicators are below the established ones. If they are overestimated, then the development of Down syndrome is suspected.
Plasma protein (PAPP-A), the value of which is lower than the established norms indicates the propensity of the fetus to diseases in the future.

An ultrasound examination should show:

how the fetus is located to eliminate the risk of ectopic pregnancy;
what kind of pregnancy: multiple or single;
whether the fetal heart rate is in line with developmental norms;
embryo length, head circumference, limb length;
the presence of external defects and violations of internal organs;
the thickness of the collar space. With healthy development, it corresponds to 2 cm. If compaction is observed, then pathology is likely;
the condition of the placenta to eliminate the risk of dysfunction.

Diagnostics	Terms of gestation	Indicators	Meaning
Ultrasound examination of the fetus. Depending on the intrauterine location and carry out: - through the skin; - transvaginal.	From 10 to 14 weeks	The coccyx-parietal size shows the maximum distance from the occiput to the coccyx of the fetus.	Allows you to accurately determine the duration of pregnancy, and confirm the presence of pathology.
		The thickness of the collar space (the cervical fold in which fluid accumulates).	What matters is not the actual presence of fluid (all embryos have it), but its amount.
		Determination of the length of the nasal bone.	If the nasal bone is not visualized, and the thickness of the cervical fold is increased, then the likelihood of developing Down syndrome is high.
		Heart rhythms.	147-171 beats per minute.
		Biparietal head size - the distance between the extreme points of the vertex in the fetal cranium.	Helps to determine the presence of fetal abnormalities, and to confirm the calculations of the moment of conception.
Biochemical (hormonal) analysis, in which the venous blood of the expectant mother is taken in an amount of 10 ml	From 10 to 13 weeks	Chorionic gonadotropin, which detects pathology of the placenta, Edwards syndrome and Down syndrome.	A decrease in the level of hCG in the blood during gestation or a slowdown in its growth indicates the risk of spontaneous miscarriage or the development of an ectopic pregnancy.
	From 10 to 13 weeks	Protein A, a protein produced by the placenta.	The decoding of the 1st trimester screening is indicated in units of Mohm. When MoM is from 0.5 to 2.5, the indicators are considered normal.

A comprehensive examination, the results of which are shown by the first screening carried out, makes it possible to detect various genetic pathologies. If a serious illness is confirmed that threatens the quality of life and health of the unborn child, then parents are offered to terminate the pregnancy artificially.

To accurately confirm the diagnosis, a woman undergoes a biopsy and puncture of the amniotic membrane to obtain amniotic fluid and examine it in the laboratory. Only after this can we confidently say that the pathology exists, and it is possible to make a final decision about the further course of pregnancy and the fate of the child.

Preparing and conducting screening

The gynecologist leading pregnancy tells the woman in detail what preparation for the procedure should be carried out. He also informs about the standard survey standards. All points of interest to her should be discussed without hiding information. There are several mandatory nuances for screening the first weeks.

Tests for hormones are taken on the same day. Better to do the 1st screening in one laboratory. The expectant mother should not worry and understand that it is extremely necessary for her to donate blood from a vein. The unpleasant sensations when passing the analysis will quickly pass, the main thing is to get the result.
Blood is donated on an empty stomach. You can drink some boiled water if you are very thirsty.
Weighing. Before screening, it is advisable to weigh yourself, since weight and height data are important for the procedure.

The test results are received by the doctor or the pregnant woman herself.

Research results and norms

Usually, laboratories issue forms that indicate the standard indicators of the norm and the results of the pregnant woman obtained in the laboratory. The future mommy can easily figure them out.

HCG rates at the first screening

These readings are normal and do not indicate abnormalities.

Indicators of ultrasound diagnostics

Based on the results, you can determine the symmetry of the cerebral hemispheres of the fetus and track how the internal organs develop. But the main task of the procedure is to identify chromosomal pathologies and exclude the risk of their development at a later date.

So screening allows you to timely detect:

chromosomal abnormalities (triploidy, characterized by an additional set of chromosomes);
defects in the development of the nervous system;
umbilical hernia;
the possible presence of Down syndrome;
predisposition to Patau syndrome, manifested by the receipt of the embryo of 3 thirteenth chromosomes instead of two. Most babies born with this rare disease have many physical disabilities and die within the first few years;
de Lange syndrome, characterized by gene mutations. Such children are greatly lagging behind in mental development and have significant physical defects;
Edwards syndrome characterized by the presence of an extra 18th chromosome. Such babies are far behind physically and mentally, and are more often born prematurely;
Lemli-Opitz syndrome, characterized by severe mental and physical retardation.

If an umbilical hernia is found, a violation of internal organs, a high frequency of heart contractions, Patau syndrome is suspected. In the absence of a nasal bone or its too small size, one existing umbilical artery and a low heart rate, the threat of Edwards syndrome is noted.

When the timing of pregnancy is accurately established, but the ultrasound does not determine the nasal bone, and the facial contours are not expressed, this indicates Down syndrome. Only an experienced specialist is involved in decoding the 1st screening, since erroneous results can lead to strong feelings of future parents

When to start worrying for a mom-to-be

As you know, there is a human factor everywhere, and even in serious laboratories mistakes can happen. Incorrect results shown by biochemistry are confused with genetic defects. That happens:

in mothers with diabetes mellitus;
for those carrying twins;
with early or late 1st screening;
with an ectopic pregnancy.

Falsified results are accompanied by factors such as:

obesity of the expectant mother;
conception by IVF, while the protein A values will be low;
experiences and stressful situations that arose on the eve of the test;
treatment with drugs, the active component of which is progesterone.

If PAPP-A, at a high rate, makes you alert only when the ultrasound results are unfavorable, then a low protein content indicates such disorders as:

freezing of the fetus;
pathology of the primary form of the nervous system of the fetus;
high probability of spontaneous abortion;
the risk of premature onset of labor;
Rh-conflict between mom and baby.

The blood test is 68% correct, and only in conjunction with an ultrasound scan can you be sure of the diagnosis. If the norms of the first screening do not correspond to the prescribed ones, it will be possible to allay fears at the next testing. It must be carried out in the second trimester of gestation. When the results of the 1st screening are in doubt, another independent laboratory can be examined. It is important to repeat the 1st screening before the 13th week of gestation.

Parents will need a consultation with a geneticist, who will recommend additional research. When a repeated study shows that the child has a predisposition to Down's syndrome, this is indicated by the thickness of the collar space and the analysis for hCG and PAPP-A. If PAPP-A is higher than it should be, and all other indicators correspond to the standard, then you should not worry. In medicine, there are cases when, despite the poor prognosis of the 1st and even the 2nd screening, healthy babies were born.

Continuing the topic:

>> about screening in the 2nd trimester

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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 had 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

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

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.

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

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 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.

To complete the study, you will need to undress from the waist down, lie on the couch with your legs bent. The doctor will very gently insert a thin special sensor in the condom into your vagina; during the examination, it will be slightly moved. It doesn't hurt, but after examining this or the next day, you may find a small amount of spotting on the pad.

How is the first transabdominal transducer screening done? In this case, you either undress to the waist, or simply lift the clothes so that you open your stomach for examination. With this 1 trimester ultrasound screening, the sensor will move along the abdomen without causing pain or discomfort.

How is the next stage of the survey carried out? With the results of an ultrasound scan, you go to donate blood. There you will also be asked to clarify some data that are important for the correct interpretation of the results.

You will not receive results immediately, but in a few weeks. This is how the first pregnancy screening takes place.

Decoding the results

1 Normal ultrasound data

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

Coccyx-parietal size (CTE) of the fetus

When screened at 10 weeks, this size is in the following range: mm on the first day of the 10th week of domm - on the 6th day of the 10th week.

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

In a 12-week pregnancy, this size is: mm at 12 weeks exactly, 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):

this bone should already be detected by a week, 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 - beats per minute
at 11 weeks -
at 12 weeks - blows per minute
at 13 weeks - a beat 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.

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".

The MoM indicator is influenced by the age risk when screening the 1st trimester: that is, the comparison is not just with the calculated median in this period of pregnancy, but with the calculated value for a given age of the pregnant woman.

Intermediate first trimester screening results normally indicate the amount of hormones in MoM units. So, the form contains the record "hCG 2 MoM" or "PAPP-A 1 MoM" and so on. If MoM is 0.5-2.5, this is normal.

The pathology is considered to be the level of hCG below 0.5 median levels: this indicates an increased risk of Edwards syndrome. An increase in hCG above 2.5 median values indicates an increased risk of Down syndrome. A decrease in PAPP-A below 0.5 MoM indicates that there is a risk in relation to both of the above syndromes, but its increase does not mean anything.

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 standards 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 within a week
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

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 rubles.

How much does screening for the 1st trimester cost by type of test: ultrasound - 2000 rubles, determination of hCG - 780 rubles, analysis for PAPP-Arubley.

Reviews of the 1st trimester screening. Many women are dissatisfied with the quality of the calculation made: among the cases where the “high risk” is set, the birth of a perfectly healthy baby was often noted. Ladies write that it is best to find a highly qualified specialist in perinatal ultrasound diagnostics, who can confirm or dispel doubts about the baby's health.

Thus, screening for the 1st trimester is a diagnosis that in some cases helps to identify the most severe fetal pathology in the early stages. It has its own characteristics of preparation and conduct. The interpretation of the results should be carried out taking into account all the individual characteristics of a woman.

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Article content (table of contents)

What is pregnancy screening

With ultrasound, the doctor examines the development of the fetus's physique and determines if there are any pathologies. If violations are found, treatment can be started on time.

How long does it take for the first screening

Patients are interested in when the 1st screening is done, and if there is a time frame that allows you to postpone or speed up testing. The timing is set by the gynecologist leading the pregnancy. It is often prescribed between 10 and 13 weeks after conception. Despite the short duration of pregnancy, the tests accurately show the presence of chromosomal abnormalities in the fetus.

Be sure to screen women at risk by 13 weeks:

have reached 35 years of age;
under the age of 18;
having genetic diseases in the family;
survivors of a spontaneous abortion before;
who gave birth to children with genetic disorders;
sick with an infectious disease after conception;
who conceived a child from a relative.

What should I show

Thanks to the first screening, the expectant mother and the doctor will know exactly how the baby is developing and whether he is healthy.

The biochemical analysis of the 1st screening during pregnancy has certain indicators:

HCG rate - detects Edwards syndrome when the indicators are below the established ones. If they are overestimated, then the development of Down syndrome is suspected.
Plasma protein (PAPP-A), the value of which is below the established norms, indicates the tendency of the fetus to diseases in the future.

An ultrasound examination should show:

how the fetus is located to eliminate the risk of ectopic pregnancy;
what kind of pregnancy: multiple or single;
whether the fetal heart rate is in line with developmental norms;
embryo length, head circumference, limb length;
the presence of external defects and violations of internal organs;
the thickness of the collar space. With healthy development, it corresponds to 2 cm. If compaction is observed, then pathology is likely;
the condition of the placenta to eliminate the risk of dysfunction.

Ultrasound examination of the fetus. Depending on the intrauterine location and carry out:

Through the skin;

Preparing and conducting screening

Tests for hormones are taken on the same day. Better to do the 1st screening in one laboratory. The expectant mother should not worry and understand that it is extremely necessary for her to donate blood from a vein. The unpleasant sensations when passing the analysis will quickly pass, the main thing is to get the result.
Blood is donated on an empty stomach. You can drink some boiled water if you are very thirsty.
Weighing. Before screening, it is advisable to weigh yourself, since weight and height data are important for the procedure.

The test results are received by the doctor or the pregnant woman herself.

Research results and norms

Usually, laboratories issue forms that indicate the standard indicators of the norm and the results of the pregnant woman obtained in the laboratory. The future mommy can easily figure them out.

HCG rates at the first screening

These readings are normal and do not indicate abnormalities.

Indicators of ultrasound diagnostics

So screening allows you to timely detect:

chromosomal abnormalities (triploidy, characterized by an additional set of chromosomes);
defects in the development of the nervous system;
umbilical hernia;
the possible presence of Down syndrome;
predisposition to Patau syndrome, manifested by the receipt of the embryo of 3 thirteenth chromosomes instead of two. Most babies born with this rare disease have many physical disabilities and die within the first few years;
de Lange syndrome, characterized by gene mutations. Such children are greatly lagging behind in mental development and have significant physical defects;
Edwards syndrome characterized by the presence of an extra 18th chromosome. Such babies are far behind physically and mentally, and are more often born prematurely;
Lemli-Opitz syndrome, characterized by severe mental and physical retardation.

When to start worrying for a mom-to-be

As you know, there is a human factor everywhere, and even in serious laboratories mistakes can happen. Incorrect results shown by biochemistry are confused with genetic defects. That happens:

in mothers with diabetes mellitus;
for those carrying twins;
with early or late 1st screening;
with an ectopic pregnancy.

Falsified results are accompanied by factors such as:

obesity of the expectant mother;
conception by IVF, while the protein A values will be low;
experiences and stressful situations that arose on the eve of the test;
treatment with drugs, the active component of which is progesterone.

If PAPP-A, at a high rate, makes you alert only when the ultrasound results are unfavorable, then a low protein content indicates such disorders as:

freezing of the fetus;
pathology of the primary form of the nervous system of the fetus;
high probability of spontaneous abortion;
the risk of premature onset of labor;
Rh-conflict between mom and baby.

Pregnancy: first and second screening - assessing the risks

Screening during pregnancy - pros and cons. Ultrasound, blood tests and additional studies.

Prenatal screenings generate a lot of conflicting opinions and reviews. Someone is convinced of their necessity, others are sure of their complete inexpediency. What kind of research is this, and should all pregnant women really be doing it? We decided to investigate this issue.

Prenatal screening is a complex of studies, the main goal of which is to identify a risk group of pregnant women with possible malformations of the child (such as: Down syndrome, Edwards syndrome, neural tube defects (anencephaly), Cornelia de Lange syndrome, Smith Lemli Opitz syndrome, triploidy, Patau syndrome).

Despite the fact that screenings include two fairly proven diagnostic methods - a biochemical blood test and an ultrasound scan, their reliability and safety are still controversial.

"Cons" number 1: ultrasound is harmful to the baby

There is a fairly widespread opinion that ultrasound negatively affects the child's nervous system, irritates him - during the examination, babies often try to hide from the apparatus, cover their heads with handles. Therefore, children whose mothers regularly had ultrasound scans during pregnancy are more anxious compared to babies whose mothers have refused ultrasound diagnostics. Is it really?

According to doctors, ultrasound cannot do any harm to the baby - modern equipment is absolutely safe. Therefore, official medicine insists that absolutely all pregnant women undergo ultrasound. After all, timely diagnostics allows, firstly, to see the full picture of the course of pregnancy, and secondly, if necessary, to correct certain problems.

Ultrasound examination is carried out at least three times per pregnancy (in the first trimester for a week, in the second - and in the third - for a week), but if necessary, the doctor may recommend to undergo it more often.

Especially important are the data obtained on the ultrasound of the first prenatal screening (at the week of pregnancy). At this time during the study:

the number of embryos in the uterus, their viability is determined;
a more accurate period of pregnancy is set;
gross malformations are excluded;
the thickness of the collar space - TVP is determined (i.e. the amount of subcutaneous fluid on the back of the child's neck is measured - normally the TVP should not exceed 2.7 mm);
the presence or absence of the nasal bone is examined.

For example, in children with Down syndrome, the fluid content is much higher than normal, and the nasal bone is often not visualized.

"Cons" number 2: a biochemical blood test gives an unreliable result

Many mothers are sure that it is impossible to draw at least some reliable conclusions from one analysis - too many factors can affect the result. And in part they are really right. However, you need to take a closer look at the analysis process in order to understand on the basis of which the doctor makes a conclusion.

A biochemical analysis is performed in order to determine the level of specific placental proteins in the blood. During the first screening, a "double test" is done (that is, the level of two proteins is determined):

PAPPA (pregnancy associated plasma protein or pregnancy associated plasma protein A);
free beta subunit of hCG (human chorionic gonadotropin).

Changes in the level of these proteins indicate the risk of various chromosomal and some non-chromosomal abnormalities. However, identifying an increased risk is not yet evidence that something is wrong with the baby. Such indicators are only a reason for more careful monitoring of the course of pregnancy and the development of the child. As a rule, if, as a result of screening the first trimester, the risk is increased for any indicators, the expectant mother is offered to wait for the second screening. In case of serious deviations from the indicators of the norm, the woman is referred to a geneticist for consultation.

The second screening takes place during the week of pregnancy. This study includes a "triple" or "quadruple test". Everything happens in the same way as in the first trimester - the woman again takes a blood test. Only in this case, the results of the analysis are used to determine not two, but three (or, respectively, four) indicators:

the free beta subunit of hCG;
alpha-fetoprotein;
free estriol;
in the case of the quadruple test, also inhibin A.

As in the first screening, the interpretation of the results is based on the deviation of the indicators from the average statistical norm according to certain criteria. All calculations are carried out using a special computer program, after which they are carefully analyzed by a doctor. In addition, when analyzing the results, many individual parameters are taken into account (race, the presence of chronic diseases, the number of fetuses, body weight, bad habits, etc.), since these factors can affect the value of the studied indicators.

In order to obtain the most reliable results, the research data of the first and second trimester in the complex must be correlated.

If, as a result of studies of the first and second trimester, some abnormalities in the development of the fetus are revealed, the woman may be offered to undergo a second screening or immediately sent for a consultation with a geneticist. If necessary, he can prescribe additional tests to make a more accurate diagnosis (for example, amniotic fluid examination, chorionic villus sampling). However, due to the fact that these studies are not entirely safe and can cause various complications of the course of pregnancy (the risk of miscarriage, the development of group or Rh-conflict, infection of the fetus, etc.), they are prescribed only in case of a high risk of pathology. However, such complications are not so common - in 12% of cases. And, of course, all research is carried out only with the consent of the expectant mother.

Thus, the first two arguments "against", from the point of view of scientific medicine, are not convincing, and rather they should be reformulated as follows: prenatal screenings are safe for the expectant mother and her baby, and all conclusions are made by the doctor taking into account a whole range of individual factors.

"Cons" # 3: "I have good heredity - I don't need screenings."

Some mothers do not see the point in undergoing screenings - all relatives are healthy, what problems can there be? Indeed, there are separate groups of women who are primarily recommended to undergo a study to identify possible pathologies in the development of the child. These are senior women (since after this age the risk of developing abnormalities in a child increases several times) and expectant mothers with certain diseases (for example, diabetes mellitus). Of course, the risk group includes those mothers whose families already have children or relatives with genetic diseases. However, the majority of doctors (and, not only in Russia, but also in many countries of Europe and America) are of the opinion that prenatal screenings are necessary for all women, especially if the pregnancy is the first.

"Cons" # 4: "I'm afraid to hear a bad diagnosis"

This is perhaps one of the strongest arguments against screening. Expectant mothers are very scared by the likelihood of hearing something bad about the development of the baby. In addition, medical errors are also troubling - sometimes screenings give a false-positive or false-negative result. There are cases when the mother was told that the child was suspected of Down syndrome, and subsequently a healthy baby was born. Of course, to be sure, such news greatly affects the emotional state of the mother. After the preliminary conclusion, the woman spends the rest of the pregnancy in constant worries, and this is also completely unhelpful for the health of the baby.

However, do not forget that the results of prenatal screening in no way serve as a basis for the diagnosis. They only identify the likely risks. Therefore, even a positive screening result will not be a “sentence” for a child. This is just a reason to get professional advice from a geneticist.

"Cons" No. 5: the identified potential deviations in the development of the child cannot be corrected

This is true - there is no way to cure or correct chromosomal abnormalities. Therefore, impressionable and vulnerable mothers, as well as women who are determined to maintain an existing pregnancy under any circumstances, can only get an extra reason for worries as a result of the screenings passed. Perhaps, indeed, the best way out in such a situation would be to refuse research, so that the mother can calmly wait for the birth of the baby.

the undoubted advantage of prenatal screenings is the ability to obtain information about the development of the child at a fairly early stage of pregnancy, go to a geneticist for a consultation, and undergo, if necessary, all additional examinations. After all, having the data, the expectant mother can already quite consciously make a decision on the further development or termination of pregnancy.

The most important argument "against": poor health of the expectant mother at the time of the study

Any, even a slight increase in body temperature, colds (acute respiratory infections, ARVI), any other viral and infectious diseases, and even stress are an unequivocal contraindication for screening. After all, each of these factors can distort the analysis data. That is why, before going to donate blood, the expectant mother must be examined by a gynecologist - the doctor will assess her general condition.

Today, prenatal screenings are not strictly mandatory, but most doctors are confident in the need for these studies. The right to make a decision remains with the pregnant woman, so that, after weighing all the pros and cons, each woman will make a choice - it is important for someone to control the situation and receive all possible information as early as possible, and for someone it is much calmer to do with only the obligatory minimum examinations, just enjoy pregnancy and believe in the best.

Irina Pilyugina, MD, PhD, gynecologist of the highest category

I have more than once faced the incompetence of our doctors!

My sister for 9 years could not have children, and now, at last, thanks to IVF at the age of 41, she became pregnant. Everyone was incredibly happy. The doctor in the LCD said on the go -type where you should give birth to an old child.Plus, after 1 screening on Friday before the weekend, I called in the evening and said that I congratulate you, Down will be born 👿 👿 👿 👿 Poor cried all weekend, could not calm down, friends advised to undergo a prenatal test (yes, it cost a lot - they paid 29500r), but they said that it was effective. And in 5-6 days you can find out for sure whether there is a pathology or not.

You can't even imagine what those 5 days were for us. The little sister got to the hospital with a threat because of nervousness.

After 5 days, the result came; the baby is healthy - no pathologies have been identified.

Male fruit.

Her husband almost beat this doctor in the antenatal clinic and wanted to sue her.

Dear mothers-to-be, don't panic over incompetent doctors.

After this story, when I got pregnant, I did not take the screening.

I did an ultrasound and I'm going to go for an antenatal test right away on Friday. Away from sin.

what would you do with a risk of 1: 163?

The ultrasounds are good, there are no external pathologies. So what to do? Should I go for amniocentesis or not? Those. and 1 and 2 screenings have the same results?

Try to retake the screening.

Poor screening. Analyzes, studies, tests, ultrasound. Pregnancy and childbirth. Deciphering the blood test, coagulogram parameters, TORCH infections, blood group, Rh factor.

You need to calm down, you don't need to cry at all, many go through this hassle in the first screening))) @@@@@@@@@@@@@

genetic screening showed too high a risk of Down syndrome.

Analyzes, studies, tests, ultrasound. Section: Analyzes, studies, tests, ultrasound. genetic screening showed too high a risk of Down syndrome.

Poor screening results

She said that the results of the paid screening will not be taken into account. The results of third-party ultrasound and screenings are perfectly taken into account, a transcript is usually attached to them.

What risk were you told? how tall? If the risk is really high, you should definitely go to a specialist. They will explain everything - what and when can be done, what threatens with what. And even if they are sent for amnio - this is not the end of the world - several of my friends did it - everyone is all right. Here after 35 is a common practice.

bad is when 1:50, for example. And then there were examples when healthy children were born. but in any case, such a risk value is an indication to make amnio.

but for a good, expert ultrasound, be sure to go.

Second screening (ultrasound). When?

Section: Analyzes, studies, tests, ultrasound. Second screening (ultrasound). At the same time, blood for the second screening is donated earlier than the screening ultrasound.

Knock knock, from the neighboring conference, about the screening 🙁

Girls, hello! Received bad results of the first screening, at the village of Down 1:50, ultrasound is normal. I decided to conduct a survey with the experienced, what risks you had.

in a child, the chromosomal syndrome is more complicated than S. Down's, MVPR, cerebral palsy, epilepsy.

but if you don’t have an abortion and are ready for any child, then just beat it up, eat well, walk more and find yourself a good obstetrician.

Screening of the 1st trimester

Section: Analyzes, studies, tests, ultrasound. Screening of the 1st trimester. I'm confused. Received the results of screening in the LCD.

Connoisseurs about the SOS collar zone!

Then - it’s strange that they didn’t have a blood test (screening), it goes along with an ultrasound scan. Or wait for the second screening. But the shoots on genetics with non-indicative.

And I'll tell you my story - at 12 weeks I had an ultrasound scan, but I got terribly ill, my record burned out. As soon as the pace subsided, after three days, I immediately, urgently, signed up for an ultrasound scan, but since there were no places to see the doctor I wanted to see, I said to sign up for anyone. the center is the best-known one in Moscow and I was sure that the doctors were appropriate. They measured a 5mm fold for me there. and said that this is the norm. Moreover, I had read about these folds before, but at the moment of euphoria, when they told me that everything was wonderful, everything was shown in detail, and I forgot. Only at my doctor I was shocked when I saw her eyes when looking at the discharge. She sent me straight to the geneticists at the TsPSIR. And I didn’t believe, I sat and sobbed in her office, I just didn’t believe that something could be wrong with my child. After all, I was told that everything is fine.

But, leaving the doctor, common sense still made me drive to another center and do an ultrasound scan where the doctor assured me 100% that the fold was only 1.5, and that there was no smell of 5, I printed all the detailed photos. Then I came home and once again looked at the ultrasound record on the DVD, well, you can't be wrong - 1.5 and 5. He measured the wrong thing for me. NOT a neck crease, but hell knows that. And he was so kind, he showed and told everything in detail. Here, I found a link to that topic of mine (I was partisan then :)

It is better to redo the ultrasound scan again, and health to you and your baby.

Without a blood test, a diagnosis is not made only by the results of an ultrasound scan! Go to another clinic. All fists are with you.

Poor screening

Poor screening. Analyzes, studies, tests, ultrasound. 1) I had blood on the 1st screening - it was nowhere worse, and the ultrasound scan is normal 2) the 2nd blood screening is normal, the ultrasound scan too.

Enjoy your pregnancy and don't think about anything bad, everything will be fine 🙂

That both ultrasound and blood are bad?

1) I have blood on 1 screening - it was nowhere worse, and the ultrasound is normal

2) screening 2nd blood is normal, ultrasound too.

Wait to get very upset.

If the time allows you (up to 13 weeks), you can donate blood again and ultrasound to redo.

first trimester screening statistics

Analyzes, studies, tests, ultrasound. Screening of the first trimester of pregnancy. Please help to decipher the results of the screening. Age 18 years.

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First screening during pregnancy- a set of examinations, the purpose of which is to identify the risk of congenital fetal abnormalities. The diagnostic test includes an ultrasound scan and a blood test from a vein. The optimal timing for it coincides with the end of the first trimester of pregnancy.

Prenatal screening shows the risk of pathology in the unborn child, but he cannot say with one hundred percent probability about its presence or absence. Deviations from the norm in its results are indications for other diagnostic studies, during which specialists will make a final diagnosis.

With the help of screening for the 1st trimester, the expectant mother can find out about a severe congenital anomaly of the fetus and decide in time to interrupt the gestation.

Terms of completion of the study

Screening in the first trimester of pregnancy can only be carried out from the first day of the 11th week to the sixth day of the 13th week. Carrying out studies at an earlier date is inappropriate, since the structures examined by ultrasound are still too small for observation, and the hormones of the biochemical test have not reached the required concentration.

Conducting an ultrasound examination at a later date does not make sense. This phenomenon is due to the fact that after the body of the fetus begins to develop the lymphatic system, the fluid of which interferes with the consideration of anatomical structures.

The optimal timing for the first screening is 11-12 weeks of gestation. At this time, biochemical tests have the smallest error, and with the help of ultrasound equipment, the anatomical structures of the unborn child are clearly visible. Also, if malformations are detected, a woman can have time to make a medical termination of pregnancy in a less traumatic way.

Indications for ultrasound and blood tests

According to the order of the Ministry of Health of the Russian Federation, screening of the 1st trimester is indicated for all pregnant women. It helps to identify malformations in the early stages of gestation and is absolutely safe for the fetus and the expectant mother. Every pregnant woman has the right to decide whether she will undergo prenatal screening.

Mandatory passage of the first screening is recommended for women belonging to one of the risk groups:

age over 40;
history of spontaneous abortion;
intrauterine fetal death during previous pregnancies;
the birth of a child with a history of chromosomal abnormalities;
transferred infectious and inflammatory disease during gestation;
the use of drugs that have a teratogenic (causing congenital anomalies) effect on the fetus during gestation;
alcohol abuse or drug use during gestation;
burdened hereditary history (the presence of congenital anomalies in close relatives);
the presence of consanguinity with the father.

Answers of the obstetrician-gynecologist to the main questions about the first screening:

Objectives of the first screening

The main goal of first trimester screening is to identify the degree of risk of congenital fetal pathology. With the help of ultrasound equipment, a specialist examines the "markers" of genetic diseases. Their presence indicates a high probability of chromosomal abnormalities.

Biochemical screening measures the amount of hormones produced by the placenta. It is called "double" because it consists of hCG and PAPP-A counts. Their deviation from normal values indicates a high probability of the presence of congenital diseases.

With the help of the studies described, specialists can establish an increased risk of certain chromosomal abnormalities - Edwards, Patau, Down, de Lange syndrome, etc. Their danger lies in the fact that many children die in the first months and years after birth, since their organs have an atypical structure and cannot fully perform their functions. But if a child manages to survive, his mental and physical development will lag far behind his peers.

Attention! Both examinations of the first screening cannot say for sure whether the fetus has a chromosomal abnormality, these tests only reflect the risk of its presence, therefore, with poor results, expectant mothers should not despair - quite often anxiety is in vain.

The high risk at the first screening is assessed by the width of the cervical fold. Normally, it should not exceed 0.3 centimeters. The greater the deviation from this value, the higher the likelihood of having a chromosomal abnormality.

Another marker of Down syndrome is the structure of the nasal bone. The high risk of a chromosomal abnormality is indicated by its absence at any stage of pregnancy. After 12 weeks, doctors measure the length of the nasal bone, normally it should exceed 3 mm. The shorter dimensions of this anatomical structure are a marker of chromosomal pathology.

In addition to chromosomal abnormalities, screening helps in the diagnosis of neural tube defects. This group of diseases is characterized by an incorrect laying of the brain or spinal cord, which is rarely compatible with life. Also, ultrasound examination can reveal abnormalities of other organs - the absence of limbs, the laying of the heart outside the chest cavity, hernial protrusion of the anterior abdominal wall, etc.

Preparing for the first screening

Ultrasound screening can be done in two ways. The first one is transvaginal - when the probe is inserted into the vagina. With this type of ultrasound examination, a woman does not need special training.

The second method of conducting ultrasound is transabdominal - when the sensor is on the surface of the abdomen. In this case, for reliable results, the bladder must be filled, so preparation for the first screening includes taking one liter of fluid one hour before the study.

For the second stage of screening in the last weeks of the 1st trimester, the expectant mother should donate blood from a vein. The sampling of material for biochemical research is carried out in the morning. For reliable results a woman should not eat breakfast before testing... On the day of donating blood, only one glass of pure non-carbonated water is allowed.

Three days before taking blood for biochemical analysis, a woman is recommended to exclude allergens from the diet. These include seafood, peanuts, milk, fish, chocolate. It is also undesirable to eat fried, salted, smoked - this food can distort the results of the study.

To obtain reliable results, a woman needs to try to relax, since the increased activity of the nervous system can affect the production of hormones in the placenta. Get a good night's sleep and rest before exploring. Also many experts recommend excluding sexual activity three days before the intended screening.

Features of the

Screening in the first trimester is usually done in three stages. The first of them - preparatory - includes a survey of complaints and examination by an obstetrician-gynecologist. The specialist collects the woman's life and hereditary history, calculates the date of conception. For the reliability of the screening results, the doctor must know the exact age of the patient, her chronic diseases, endocrine pathologies, and the presence of IVF.

Without fail, the doctor finds out whether there are hereditary diseases in the family. Also, the specialist learns about the course of previous pregnancies - the presence of miscarriages, the birth of a child with congenital anomalies, etc. Expectant mothers with a burdened hereditary history are shown genetic screening.

After consulting a doctor, the woman is given a referral for ultrasound examination and biochemical analysis. The order in which they are performed differs in different clinics.

Sometimes both tests are done on the same day. Most often, this happens if the ultrasound is done transvaginally, since a large amount of water must be consumed before transabdominal ultrasound examination. This can skew the results of the first screening for placental hormones.

Sometimes the research is carried out in two stages. On the first day, a woman undergoes an ultrasound scan, which calculates the date of conception. The obtained values are necessary to decipher the results of the biochemical test, since the amount of hormones changes every day.

Less commonly, women first donate blood for a biochemical test. With the results obtained, the expectant mother goes to an ultrasound scan, where the gestation period is calculated again.

Ultrasound screening

Usually, an ultrasound scan of the fetus does not exceed 30 minutes. If the examination is performed transvaginally, a disposable condom is put on the transducer and then inserted into the vagina. When done correctly, a pregnant woman should not experience discomfort.

With transabdominal ultrasound, the front wall of the abdomen of the expectant mother is lubricated with a special gel. The sensor of the device will slide over it, the image is shown on the monitor. Such a study also does not cause discomfort in a pregnant woman.

Many women ask to determine the sex of the baby at the first screening. Some doctors may try to look at the pelvic area of the fetus. However, for accurate results, the baby must be facing the anterior uterine wall.

The longer the gestation period, the higher the likelihood of correctly determining the sex of the child. At 11 weeks, the number of successful attempts does not exceed 50%. At the end of 13 weeks, in 80% of cases, the doctor can determine the gender of the baby.

Certain conditions must be met for ultrasound screening. The first of them is the length of the fetus from the coccyx to the crown of the head at least 4.5 centimeters. Second, the unborn child must take the desired position in the uterine cavity. To do this, the doctor may ask the woman to move or cough.

On an ultrasound examination, the doctor assesses the following basic parameters:

CTE - the length of the fetus from the end of the spine to the crown;
circumference of the skull;
BPR - the length of the space between the parietal tubercles;
TVP - the thickness of the collar space (cervical fold);
pulse;
the length of the bones of the limbs;
presence, position, structure of internal organs;
anatomical structure of the placenta;
the presence and structure of the nasal bone.

First screening rates:

Gestational age

Nasal bone, mm

Pulse, beats / min

If indicated or at the request of a pregnant woman, the doctor can conduct an additional study using a Doppler probe. This test shows the state of blood exchange between the vessels of the uterus and the placenta, pathologies speak of oxygen starvation of the fetus. Also, Doppler ultrasound allows you to see the number of vessels in the umbilical cord - normally there should be two arteries and one vein.

Biochemical screening

To assess the amount of hormones produced by the placenta, specialists take blood from a vein. This procedure is practically painless; if you have fear, you should not look at the syringe. First, the laboratory assistant puts a tourniquet on the shoulder, then the woman needs to clench her fist several times. After the described manipulations, the specialist inserts a needle into a vein and takes a few milliliters of blood.

Screening evaluates the amount of human chorionic gonadotropin. This hormone is produced by the placenta, its amount in the blood increases until the 11th week, then it decreases slightly. Many chromosomal and placental abnormalities are accompanied by changes in the amount of hCG.

Expectant mothers have to undergo many tests and undergo regular examinations by doctors. Among the large number of examinations, it is easy to get confused and many women do not know what this or that analysis is for. In most cases, the expectant mother really does not need to worry once again, but nevertheless, it is necessary to know the purpose of screenings and tests. Blood for screening is taken several times during pregnancy.

The first baseline test is done early in pregnancy and is known as the 12 week screening. This type of medical examination can be done between the 10th and 13th week of pregnancy. It is advisable to undergo an examination before pregnancy in order to assess the health of the expectant mother. However, as practice shows, most often the first examination is carried out when the patient is registered. The first screening must be done in case of a high risk of the formation of pathologies.

Also, any woman has the right to pass any tests at will:

First pregnancy over 35 years of age.
The presence of diseases that are inherited and genetic abnormalities.
Marriage between close relatives.
The analysis is carried out if there were previously cases of miscarriage, missed pregnancy and other disorders.
Taking potent medications that are not recommended for expectant mothers while carrying a fetus.
Consumption of alcohol, drugs and illegal drugs.
Work with harmful working conditions.
Detection of genetic and other abnormalities in children born to a woman earlier.
Postponed severe inflammation and viral diseases in early pregnancy.

The patient's venous blood is used for screening. If necessary or at the request of the patient, the standard set of parameters for analysis can be expanded. Biochemical research can include more than 20 basic parameters. In the absence of a clear medical indication, additional tests may be charged. Private clinics and laboratories charge a fee for a standard examination, and each additional parameter for an additional fee. It is best to discuss the need for research with your doctor.

Diagnostics

Every woman who is expecting a baby has the right to decide for herself whether she needs to be screened. From the point of view of the law, this type of examination is recommended by doctors, but the expectant mother has the right to refuse tests.

However, this is an unreasonable approach, from the point of view of the health of the mother and baby, it is better to find out about any possible deviations or violations as soon as possible.

The results of 1 screening give doctors a lot of useful information about the health and development of the unborn baby. As a rule, a standard set of investigated parameters is used, which makes it possible to detect the following deviations:

The risk of developing pathological changes in the fetus
Down Syndrome
Patau syndrome
Disorders in the development and pathology of the neural tube of the fetus
Abnormal chromosome set
Physiological defects of the internal organs of the developing fetus

Screening tests do not provide a diagnosis or determine with certainty whether the child will be ill. Based on the results of the analysis, one can judge the degree of risk for the development of a particular deviation. Women who are at risk may be offered additional examination. With the help of an invasive test, the amniotic fluid is taken for analysis.

Preparation for analysis

Correct blood sampling and preparation for it ensures the reliability of the results obtained. Blood for research is taken from a vein, but usually the material is taken completely painlessly. The procedure is carried out in a doctor's office or in a laboratory room. Some private medical institutions can carry out sampling at home for an additional fee:

The main question that causes a lot of controversy: are tests carried out on an empty stomach or not? Blood should be donated strictly on an empty stomach, even if the feeling of hunger is very strong, you cannot eat, you can only drink clean water. You can have breakfast right after taking blood, so many pregnant women take sandwiches or other snacks with them so as not to be hungry.
On the eve of the test, it is not recommended to eat chocolate, fatty meat and seafood.
When women donate blood, a calm atmosphere is needed. Excitement, fear, brisk walking to the doctor's office can provoke the activity of certain chemicals and enzymes inside the body.
Doctors recommend excluding intimacy 2-3 days before the analysis.

Test parameters

A blood test is carried out in the laboratory. When a blood sample is donated, a test is carried out and the patient or her doctor receives a form with the results. Any questions should be consulted with a doctor. One indicator is called beta-chorionic gonadropin or β-hCG. It is a hormonal substance that is responsible for the normal development of the fetus in the earliest stages. At first, the indicator rises significantly, then gradually decreases.

The norms for β-hCG at various stages of pregnancy have been established for screening:

Week 10: 25.8-181.6 ng / ml
11 weeks: 17.4-130.3 ng / ml
12 weeks: 13.4-128.5 ng / ml
Week 13: 14.2-114.8 ng / ml

It is important that the β-hCG index is within the established norms. High levels of the hormone may indicate the development of Down syndrome in the fetus. Also, this indicator rises with multiple pregnancies, early manifestation of toxicosis and established diabetes mellitus in the expectant mother. A low β-hCG content may indicate the development of Edwards syndrome, placental insufficiency, or be a sign of an ectopic pregnancy.

With low hormone levels, the risk of miscarriage is very high.

The second main indicator is protein A or PAPP-A. This substance is of a protein nature and is responsible for the normal development and functioning of the placenta. Exceeding the norm of this indicator is not considered a violation in the functioning of the body. A decrease in the concentration of PAPP-A leads to a threat of miscarriage and may be a sign of the development of Down syndrome, Cornelia de Lange and other pathologies:

10-11 weeks: 0.45-3.73 IU / ml
11-12 weeks: 0.78-4.77 IU / ml
12-13 weeks: 1.03-6.02 IU / ml
13-14 weeks: 1.47-8.55 IU / ml

Based on the data obtained, the laboratory calculates another parameter: MoM - coefficient. This value shows the deviation of the values obtained as a result of the analysis of the patient's blood in comparison with the average values established as the norm. For a healthy woman and a normally developing fetus, MoM should be in the range of 0.5-2.5. During multiple pregnancies, the rate rises to 3.5.

Test reliability and risks

Deciphering the results of a blood test for screening should be carried out only by a qualified doctor who is familiar with the patient's medical history. It should also be borne in mind that screening for twins will show a completely different result. The second child increases the levels of certain chemicals in the mother's body. Each doctor has information with recommended standards for the studied parameters.

However, one should take into account the individual characteristics of the body and the composition of the patient's blood before pregnancy.

With screening analysis and the correctness of the research at all stages, the reliability of the result is estimated at 95%. However, the analysis cannot determine with certainty whether the fetus will have a pathology or not. The degree of risk is assessed.

Results contain numeric notation and verbal expression:

"Low" / 1: 10000 (and below this mark), this means the presence of a low degree of risk for the development of any pathological conditions of the fetus.
"Average" / 1: 1000, means that there is an average degree of risk, additional examination is possible.
"High" / 1: 380 means that the fetus is more likely to have developmental disorders. Additional tests are recommended.
"Extremely high" / 1: 100, means that the woman needs additional examinations and consultation with a geneticist. In some cases, your doctor may recommend termination of the pregnancy.

After the results are obtained, a good or bad prognosis is possible. According to the results of the first prenatal examination, some types of pathologies can be excluded. What if the screening is poor? First of all, don't worry, stress can harm many more potential risks. We will have to decide how ready the future parents are for the appearance of a child with special needs.

Triple test

Blood at the second screening is donated at 20-25 weeks of pregnancy. Take the test, as well as the first one, on an empty stomach. After the woman has done the analysis, she is consulted with a doctor. The second test includes an analysis of those basic indicators: hCG, alpha-fetoprotein and free estirol.

The reliability of the second screening is lower compared to the first.

In medicine, it is generally accepted that this type of research is 80% effective. However, the validity of the 2 screening test is only possible if the exact date of conception is known. Otherwise, the truthfulness of the results obtained drops to 20%, since the norms for hormones and chemicals change with each week of pregnancy.

For blood, screening is carried out several times, at the same time it is necessary to do an ultrasound examination. Modern diagnostic and research methods of medicine make it possible to identify pathological and genetic changes in the heart in early pregnancy. If necessary, consultations with narrowly focused specialists and treatment are carried out.

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