Blood for pathology. How true are the results? "Three Whales" studies

Genetic damage during the fetal formation of a baby can occur at any stage. Genetic and chromosomal changes are detected by prenatal screening. This laboratory research blood to determine the concentration of the hormones ACE and hCG. The hormone alpha-fetoprotein is responsible for possible somatic and hereditary abnormalities.

Chromosomal pathology of the fetus is established on early dates gestation, during the first "triple test". This includes blood tests and an ultrasound.

The optimal time for screening is 12 weeks of gestation. During this period, the corpus luteum takes responsibility for the production of AFP and hCG.

The main role in the detection of congenital deformities is taken by alpha-fetoprotein. Its concentration increases with gestational age, but excessively high values or their decrease indicates a possible chromosomal failure.

Data and blood tests are compared using a special program that displays results in proportion.

Some somatic pathologies can only be detected using ultrasound. For example, underdevelopment of limbs or internal organs, the absence of a body part, or other deformities not associated with chromosomal pathology.

In this case we are talking about disturbed embryogenesis for a number of reasons.

During pregnancy, they are carried out several times, but only if there are grounds.

So, for example, doubtful data of the first trimester are checked at 18-20 weeks to confirm or refute the results obtained earlier.

At this time, the outlines of the child, organs and systems are clearly visible.

When to take

– obligatory view research for women awaiting replenishment in the family. It is carried out in order to predict the further development of pregnancy.

According to statistics, a fetus with chromosomal abnormalities detected in the early stages is not viable.

The blood of a pregnant woman is analyzed, in which the level of hormones responsible for the development of the fetus is detected. AFP is responsible for:

transport useful substances;
participates in the formation of surfactant in the pulmonary alveoli;
is a source of polyunsaturated fatty acids;
responsible for the level of intravascular pressure;
protects the fetus from negative impact maternal hormones.

Blood for screening analysis is given several times during the gestational period:

in the first trimester no later than 12 weeks of gestation;
in the second trimester, subject to negative results after the first study;
at the end of the middle of the third trimester (rare).

A repeat is necessary for the following factors:

in case of consanguinity between spouses or close relatives;
stillbirth in the anamnesis of the expectant mother;
age ;
harmful effects of ionizing radiation;
radiography in the first trimester;
genetic mutations in the family of the spouse;
hereditary diseases of a genetic nature on the part of the mother.

What can AFP signal?

The triple screening test includes a study of hormone levels and ultrasound data. Alpha-fetoprotein is responsible for possible chromosomal abnormalities.

The concentration of the hormone can be increased, and may have underestimated data. In both cases, we are talking about the pathological course of gestation.

An increase in AFP levels is associated with:

bearing at the same time. In this case, ultrasound confirms or refutes a multiple pregnancy;
anomalies in the development of the neural tube;
pathology of internal organs: kidneys, liver, absence of the anterior abdominal wall;
necrotic changes in the liver;
malformations of the gastrointestinal tract;
chromosomal mutations;
absence of a brain.

A decrease in AFP data signals:

cystic skid;
hydrocephalus;
trisomy 18;
increased risk spontaneous miscarriage.

The term of the trimester and AFP indicators have significant differences, therefore, a study is carried out using ultrasound in the complex.

The specialist determines the height, weight, size collar space and nasal bones.

The organs and systems of the baby are clearly visible on the ultrasound monitor. Heart rhythms, medulla and limbs (down to the fingers) are determined.

At a later date, the appearance and other details are visualized. The combination of ultrasound and blood test shows complete picture about the child being born.

How to pass

For getting reliable results the expectant mother should refuse to eat on the day of blood sampling, do not take medications, and in case of admission, notify the health worker.

To avoid physical activity and use fatty foods the day before.

Assembled in the morning. Ultrasonography held on the same day or the day before, but not later. The test material is venous blood.

Who deciphers and how

Decryption is carried out by a special computer program that gives the result as a percentage.

In the future, the data are reviewed by a gynecologist and a specialist in the field of genetics.

Normal screening test results remain unconfirmed. Upon receipt of negative data, the patient should consult a geneticist.

At the appointment with a geneticist, the doctor explains the data obtained and provides recommendations on prolonging the pregnancy.

Some anomalies suggest further non-viability of the fetus, so the abortion is a set.

Many chromosomal abnormalities can be confirmed or refuted by research. amniotic fluid: , And . The data obtained 100% confirm the diagnosis.

There are other methods for diagnosing blood, but they are carried out at the beginning of pregnancy.

How true are the results?

The triple prenatal test is one of the reliable methods for diagnosing deformities during uterine life. However, it may also have some errors.

For example, when the timing of the test was not met or the patient neglected the process of blood collection.

The screening is repeated several times, which significantly reduces the possibility of erroneous results, the main thing is to listen carefully to the doctor and conduct all studies on time.

In case of doubt about the actions of the doctor, the pregnant woman can be tested again in an independent laboratory.

What to do when a pathology is detected

Negative data aggravates the condition of the pregnant woman, but there is no need to panic. Screening is only a factor in a possible genetic abnormality.

Modern medicine can help the fetus get rid of physical abnormalities, eliminate developmental anomalies.

Chromosomal abnormalities are not treatable, and a pregnant woman has a choice to give birth to a baby with developmental disabilities, or to terminate the pregnancy.

Doctors in this case are the best advisers. It is important to consider that there are pathologies in which the fetus cannot survive.

Useful video: tests for malformations or screening during pregnancy

Pregnancy is a joyful event for every woman. The expectant mother listens sensitively to every movement of the baby and awaits with trepidation the result of the planned diagnostics. It is good when the doctor says after the examination that the child is healthy, but this is not always the case.

Unfortunately, there are serious pathologies, after the determination of which the future parents face an acute question - to save the fetus or terminate the pregnancy.

Pregnancy

Such disorders may be genetic or spontaneously acquired. The first develop from the conception phase and can be diagnosed as early as the first trimester of pregnancy. Acquired anomalies occur suddenly and are diagnosed at any period of gestation. Let's consider in detail each of the types.

Chromosomal abnormalities

Such a congenital deviation in the development of the fetus is caused by errors in the structure or number of chromosomes and appear even at the stage of maturation of the egg or sperm.

An incorrect number of somatic chromosomes provokes the development of syndromes:

Down. Caused by a problem with the twenty-first chromosome. Characteristic indicators of the disease are slow growth, inhibition of mental reflexes, and a non-standard appearance. Malformations of internal organs.

A child with Down syndrome

Patau. Deviations in the thirteenth chromosome. Common signs include: numerous physical abnormalities, idiocy, the presence of a large number of fingers on the limbs, underdevelopment of the genital organs, deafness. Children with Patau syndrome do not live even a year.

Child with Patau syndrome

Edwards. Eighteenth chromosome disorders. Manifested by an underdeveloped jaw, mouth, palpebral fissures, deformed ears. The maximum life expectancy of such a baby is one year.

Child with Edwards syndrome

Unfortunately, the names of these syndromes sound more and more every year. One of the reasons for their spread is poor ecology.

Syndromes provoked by a violation of the number of sex chromosomes:

Shereshevsky-Turner. A girl is born without an X chromosome. In the future, she will suffer from somatic disorders and will not be able to conceive.
Klinefelter. Characteristic for boys. Manifested by mental underdevelopment, infertility and sexual infantilism.

Deviations provoked by the multiplication of the chromosome set:

triploidy.
Tetraploidy.

Such deviations lead to spontaneous miscarriage or stillbirth.

Separately, genetic disorders are distinguished without an increase or decrease in the number of chromosomes, due to DNA damage at the level of individual genes (gene diseases).

Chromosomal and gene diseases cannot be cured, even if they are detected early. The born child will be doomed to prolonged suffering, so doctors recommend terminating the pregnancy in such cases.

Acquired diseases

These include:

Deformed or missing viscera and limbs.
Disturbances in the structure of the skull.
Heart defects.
Spinal anomalies.
Cerebral hyper- and hypoexcitability.

Heart disease

Analyzes for pathology during pregnancy

Prenatal diagnosis possible violations in the development of the embryo is a complex and capacious event, consisting of several stages. The most difficult of these is screening for fetal pathologies, which involves a set of checks that a woman must undergo at 12, 20 and 30 weeks of gestation. According to the standard, this screening includes a blood test to detect chromosomal abnormalities.

The study consists of the following activities:

Blood tests for fetal pathology.
Chorionic biopsy.
Cordocentesis.

Let's consider each of them in detail.

Diagnostics

Blood test for fetal abnormalities in development

An analysis for fetal pathology at 12 weeks consists of two parts:

Checking the concentration of the free β-subunit of hCG.
The study of plasma protein A.

In the second trimester of pregnancy, the expectant mother donates blood to check:

Total hCG and concentration of free β-subunit.
Protein AFP.
free estriol.

According to the standard, along with a blood test, an ultrasound is performed. When deciphering a blood test for malformation of the embryo, the data of the blood test and ultrasound diagnostics. These studies are carried out on an empty stomach. Three days before the procedure, a pregnant woman is recommended to go on a diet - exclude flour products, dairy and fried foods from the diet.

Analysis

Chorionic biopsy

With this diagnostic method, chorion tissues are taken to detect and prevent chromosomal pathologies and monogenic abnormalities. It involves a puncture of the uterus, which is carried out through:

Abdominal wall.
The cervix.
Vagina.

The puncture is performed using special forceps and an aspiration catheter.

Important! If parents want to detect malformations in their unborn baby, they can use the chorion biopsy, since it can be performed from 9 to 12 weeks of pregnancy. The test result will be ready in a few days.

Indications for chorionbiopsy include:

Mother's age over 34 years.
Previously born child birth defects development, monogenic or chromosomal pathologies.
Genetic predisposition to chromosomal and gene mutations.
Increased according to the results of ECHO at 10-14 weeks, the thickness of the collar space (more than 3 mm - suspicion of Down's syndrome).

You need to prepare for a chorionbiopsy: do not eat protein foods for several days and reduce the consumption of sweets. The only, but very significant drawback of the procedure is its soreness and the possibility of bleeding. But with experienced medical staff, the risk is minimal.

Chorionic biopsy

Cordocentesis

The subject of the study of this technique is umbilical (cord) blood for fetal pathology. Cordocentesis may be performed along with amniocentesis (analysis amniotic fluid). Performed after 18 weeks of pregnancy.

The procedure is performed like this: future mother make a puncture of the abdominal anterior wall and pump out through it from the umbilical vessel not a large number of blood. This survey reveals:

Chromosomal pathologies.
Hereditary ailments.
hemolytic abnormalities.
Rhesus conflict.

The attending physician is obliged to decipher the result of the analysis.

Cordocentesis

Ultrasound diagnostics

The most reliable and accurate diagnostics for which you do not need to specially prepare. It is carried out at the twelfth week of pregnancy. At this time, the technique already shows:

Deviations in the formation of the central nervous system.
Underdevelopment of the anterior abdominal wall.
Vertebral pathologies of the embryo.
Development of an umbilical hernia.
Underdevelopment of limbs or complete absence.
Down Syndrome.

A planned ultrasound scan, performed at the twentieth week of pregnancy, can record all open fetal deviations, since at this moment the unborn baby has already formed internal organs and systems.

Ultrasound at 30 weeks is considered the most difficult psychologically, since it can diagnose or challenge pathologies obtained from other studies.

In addition to the undeniable advantages, ultrasound does not show:

Problems with vision and hearing.
Mental retardation.
Obstruction of the hepatic ducts.
Problems with heart partitions.
Diseases of a genetic nature.
Diseases caused by an incorrect number of chromosomes.

ultrasound

Who is assigned the analysis

Each registered pregnant woman can determine the chromosomal pathology of the unborn child at the tenth week of pregnancy.

At the twelfth week, women should undergo this diagnosis so that if they receive a positive answer, they can decide whether to leave the child or terminate the pregnancy.

Risk group

Fortunately, not all expectant mothers are required to undergo all of the above tests and diagnostics. Gynecologists have compiled a table with factors that increase the possibility of developing fetal pathologies. The most common include:

Pregnancy after 35 years.
The presence in the family or close relatives of a child with disabilities.
Miscarriages, stillbirths and missed pregnancies in history.
Heredity (for example, one of the parents has Down syndrome).
Taking antibiotics and serious pharmaceuticals during pregnancy.
Radiation exposure.

If a pregnant woman falls into this group, the specialist conducts a conversation with her about possible pathologies baby, tells in detail how to identify it, and directs to everything necessary tests and diagnostics. Doctors and future mom they pursue one goal - to find out the state of health of the baby and decide whether to be born to him.

Risk group

What can analysis show?

Conducting a triple and double test allows you to determine in a child:

Down syndrome;
Edwards syndrome;
neural tube defects;
Patau and de Lange syndromes;
violation of the functionality of the CCC;
abnormal organ structure.

What's next

The subsequent actions of future parents depend on the timeliness of the detection of pathologies and their nature. If the deviation is too serious, and the baby will not live more than a year, experts recommend terminating the pregnancy. With minor external defects the doctor may recommend the use of services plastic surgeons.

In any case, parents should listen to the opinion of professionals and make a decision after weighing all the arguments.

Get a blood test for chromosomal mutations. Research included in the program comprehensive screening pregnant women and allows you to calculate the risk of having a handicapped child with an accuracy of 98%.

There is an opinion that chromosomal rearrangements in the genetic code of a child occur only against the background of “bad” heredity. However, it has been scientifically proven that healthy patients also have the risk of stillbirth, self-abortion, the birth of a baby with physical and mental disabilities. Therefore, by order No. 572 of the Ministry of Health of the Russian Federation of November 01, 2012, testing for chromosomal mutations is recommended for all pregnant women.

The cost of diagnosing chromosomal pathologies

Why take an analysis for chromosomal abnormalities of the fetus

The analysis allows you to recognize gene mutations until the moment when it will be possible to terminate the pregnancy without harm to the health of the woman. The mechanism that triggers chromosomal rearrangements and leads to anomalies such as Down syndrome, Patau, Turner, Edwards is not fully understood. Therefore, the prerequisites for fetal developmental anomalies should be identified as early as possible.

In our center, as part of prenatal screening, in addition to a biochemical blood test, a non-invasive test (NIPT), Natera (USA), informative already at the 9th week of pregnancy, can be done.

Refusal of the examination or late examination genetic analysis prevent the birth of a handicapped child.

Specialists

Preparation and holding

The optimal time for submitting the analysis for chromosomal pathologies- 12 weeks, since at this time the signs of genetic abnormalities are most pronounced. Blood is examined only after receiving the results of the ultrasound, otherwise the interpretation of the results will be erroneous.

An analysis of venous blood (the material is taken on an empty stomach) will show the level of AFP, hCG, PAPP-A - substances that are produced by the fetus and placenta. Using blood markers, the pattern of embryo development is assessed, the morphology (structure) of DNA is examined, and extra or damaged chromosomes are identified.

Deciphering and calculating risks

According to the results of ultrasound, the risks are calculated based on the number of markers detected simultaneously. If 1 marker is detected, for example, underdevelopment of the nasal bones, the prognosis of the risk of chromosomal pathology is 2%, and with a combination of 8 or more markers - 92%.

When deciphering blood markers, any deviations from the normative indicators are interpreted as signs of gene mutations. For a period of 12 weeks, they should be as follows:

The lack of AFP protein indicates the development of an autoimmune reaction - the mother's body rejects the fetus. This condition is fraught with miscarriage and fetal death.

Reduced hCG level indicates fetal growth retardation placental insufficiency. An increase in indicators suggests the risk of Down syndrome, choriocarcinoma, and hydatidiform mole.

A low level of PAPP-A indicates an underdevelopment of the placenta, large sizes fetus.

As a rule, all indicators are studied in aggregate, with a "link" to the results of ultrasound.

Where to go in Moscow

The Women's Medical Center is the only clinic in Moscow with a unique blood laboratory. We conduct not only general clinical studies, but also all possible analyzes on the pathology of hemostasis and chromosomal structure.

During pregnancy, various tests and studies can diagnose fetal chromosomal abnormalities, which are inherently hereditary diseases. They are due to changes in the structure or number of chromosomes, which explains their name.

The main cause of occurrence is mutations in the germ cells of the mother or father. Of these, only 3-5% are inherited. Due to such deviations, about 50% of abortions and 7% of stillbirths occur. Since these are serious gene defects, throughout pregnancy, parents should be more careful about all prescribed tests, especially if they are at risk.

If the parents (both) have hereditary diseases in the family, they first need to know what it is - fetal chromosomal pathologies that can be detected in their child while he is still in the womb. Awareness will help to avoid unwanted conception, and if this has already happened, to exclude the most severe consequences, starting from the intrauterine death of the baby and ending with external mutations and deformities after his birth.

At the normal healthy person chromosomes line up in 23 pairs, and each is responsible for a specific gene. In total, 46 are obtained. If their number or structure is different, they speak of chromosomal pathologies, of which there are a lot of varieties in genetics. And each of them entails dangerous consequences for the life and health of the baby. The main causes of this kind of anomaly are unknown, but there are certain risk groups.

With the world on a string. One of the rarest chromosomal abnormalities is called syndrome cat's cry. The reason is a mutation of the 5th chromosome. The disease manifests itself in the form of mental retardation and the characteristic crying of a child, which is very reminiscent of a cat's cry.

Causes

In order to prevent or recognize fetal chromosomal pathologies in time during pregnancy, doctors should interview future parents about hereditary diseases and the living conditions of their family. According to recent studies, gene mutations depend on this.

There is a certain risk group, which includes:

the age of parents (both) is over 35 years;
the presence of HA ( chromosomal abnormalities) from blood relatives;
harmful working conditions;
long-term residence in an ecologically unfavorable area.

In all these cases, there are enough high risk chromosomal pathology of the fetus, especially in the presence of hereditary diseases at the gene level. If these data are detected in a timely manner, doctors are unlikely to advise the couple to give birth at all. If conception has already occurred, the degree of damage to the child, his chances of survival and further full life will be determined.

Origin mechanism. Chromosomal pathologies develop in the fetus when a zygote is formed and the sperm and egg merge. This process uncontrollable, because it is still little studied.

signs

Since the process of occurrence and development of this kind of abnormalities has not been sufficiently studied, markers of fetal chromosomal pathology are considered conditional. These include:

, drawing pains in the lower abdomen in early pregnancy;
low levels of PAPP-A (plasma protein A) and AFP (a protein produced by the body of the embryo), elevated hCG (chorionic gonadotropin- placental hormone): to obtain such data, blood is taken from a vein for fetal chromosomal pathology for a period of 12 weeks (+/- 1-2 weeks);
the length of the nasal bones;
enlarged neck fold;
fetal inactivity;
enlarged renal pelvis;
slow growth of tubular bones;
earlier aging or hypoplasia of the placenta;
poor results of dopplerometry (ultrasound method for detecting circulatory pathologies) and CTG (cardiotocography);
- And ;
hyperechoic intestine;
small size of the maxillary bone;
enlarged bladder;
cysts in the brain;
swelling in the back and neck;
hydronephrosis;
facial deformities;
umbilical cord cysts.

The ambiguity of these signs is that each of them individually, like the entire complex listed above, can be the norm, due to individual characteristics body of the mother or child. The most accurate and reliable data are usually given by a blood test for chromosomal pathologies, ultrasound and invasive techniques.

through the pages of history. Having examined the chromosomes modern people, scientists found that they all got their DNA from one woman who lived somewhere in Africa 200,000 years ago.

Diagnostic methods

The most informative method for diagnosing fetal chromosomal pathologies is the first screening (it is also called double test). Do at 12 weeks pregnant. It includes:

Ultrasound (markers indicated above are detected);
a blood test (taken from a vein on an empty stomach) showing the level of AFP, hCG, APP-A.

It should be understood that this analysis for fetal chromosomal pathologies cannot give an accurate, 100% confirmation or refutation of the presence of anomalies. The task of the doctor at this stage is to calculate the risks, which depend on the results of the studies, the age and medical history of the young mother. The second screening (triple test) is even less informative. The most accurate diagnosis is invasive methods:

chorion biopsy;
cord blood sampling;
amniotic fluid analysis.

The purpose of all these studies is to determine the karyotype (a set of features of a set of chromosomes) and, in connection with this, chromosomal pathology. In this case, the accuracy of diagnosis is up to 98%, while the risk of miscarriage is no more than 2%. How is the decoding of the data obtained in the course of these diagnostic techniques?

Ultrasound and risks to the fetus. Contrary to the widespread myth about the dangers of ultrasound for the fetus, modern equipment allows you to reduce negative impact Ultrasound waves on the baby to zero. So do not be afraid of this diagnosis.

Deciphering and calculating risks

After the first double screening made, ultrasound markers of chromosomal pathology of the fetus, which were identified during the study, are analyzed. Based on them, it calculates the risk of developing genetic abnormalities. The very first sign is an abnormal size of the collar space in an unborn child.

Ultrasonic markers

Absolutely all ultrasound markers of fetal chromosomal pathology of the 1st trimester are taken into account in order to make the necessary calculations of possible risks. After that clinical picture complemented by a blood test.

Blood markers

All other indicators are considered deviations from the norm.

In the second trimester, inhibin A, unconjugated estriol and placental lactogen are also evaluated. All decoding of the results of the studies carried out is carried out by a special computer program. Parents can see the following values as a result:

1 in 100 - means that the risk of genetic defects in the baby is very high;
1 in 1000 is the threshold risk of fetal chromosomal pathology, which is considered normal, but a slightly underestimated value may indicate the presence of some kind of anomaly;
1 in 100,000 is a low risk of fetal chromosomal pathology, so you should not be afraid for the health of the baby from the point of view of genetics.

After the doctors calculate the risk of chromosomal pathology in the fetus, either additional studies are prescribed (if the value obtained is lower than 1 in 400), or the woman calmly nurses the pregnancy to a successful outcome.

It's curious! Male Y chromosome- the smallest of all. But it is she who is transmitted from father to son, preserving the continuity of generations.

Forecasts

Parents whose child was found to have chromosomal pathologies in utero should understand and accept as a given that they are not being treated. All that medicine can offer them in this case is an artificial termination of pregnancy. Before making such a responsible decision, you need to consult with doctors on the following issues:

What kind of pathology was diagnosed?
What consequences will it have for the life and health of the child?
Is there a risk of miscarriage and stillbirth?
How old do children live with this diagnosis?
Are you ready to become the parent of a disabled child?

To accept correct solution about whether to leave a sick baby or not, you need to objectively evaluate everything possible consequences and the results of fetal chromosomal pathology together with the doctor. In many ways, they depend on what kind of genetic anomaly doctors suggest. After all, there are enough of them.

Curious fact. Patients with Down's syndrome are usually called sunny people. They are rarely aggressive, most often very friendly, sociable, smiling and even talented in some ways.

Diseases

The consequences of chromosomal pathologies detected in the fetus can be very different: from external deformities to CNS damage. In many ways, they depend on what kind of anomaly occurred with the chromosomes: their number has changed or mutations have affected their structure. Among the most common diseases are the following.

Violation of the number of chromosomes

Down syndrome is a pathology of the 21st pair of chromosomes, in which there are three chromosomes instead of two; accordingly, such people have 47 instead of the normal 46; typical signs: dementia, delay physical development, flat face, short limbs, open mouth, strabismus, bulging eyes;
Patau syndrome - violations in the 13th chromosome, a very severe pathology, as a result of which numerous malformations are diagnosed in newborns, including idiocy, multi-fingeredness, deafness, mutations of the genital organs; such children rarely live to a year;
Edwards syndrome - problems with the 18th chromosome, often associated with the advanced age of the mother; babies are born with a small lower jaw and mouth, narrow and short palpebral fissures, deformed ears; 60% of sick babies die before 3 months, and 10% live up to a year, the main causes of death are respiratory arrest and heart defects.

Violation of the number of sex chromosomes

Shereshevsky-Turner syndrome - abnormal formation of the gonads (most often in girls), due to the absence or defects of the sex X chromosome; among the symptoms - sexual infantilism, skin folds on the neck, deformity of the elbow joints; children with such a chromosomal pathology survive, although childbirth is very difficult, and in the future, with proper supportive treatment, women can even bear their own baby (through IVF);
polysomy on the X or Y chromosome - a variety of chromosome disorders, characterized by a decrease in intelligence, increased likelihood development of schizophrenia and psychosis;
Klinefelter's syndrome - disorders of the X chromosomes in boys, who in most cases survive after childbirth, but have a specific appearance: lack of vegetation on the body, infertility, sexual infantilism, mental retardation (not always).

polyploidy

such a chromosomal pathology in the fetus always ends in death even before birth.

Why gene mutations occur at the chromosome level, scientists are still trying to find out. However, this is still only a matter of the future, and at this point in time, chromosomal pathologies detected in utero in the fetus account for up to 5% of all cases.

What should parents do when they hear such a diagnosis? Do not panic, reconcile, listen to the doctors and make the right decision together with them - to leave a sick baby or agree to an artificial termination of pregnancy.

During pregnancy are often detected various pathologies and deviations (diseases, complications, deficiency of nutrients, vitamins and minerals).

During the period of bearing a child, a woman is forced to pass a large number of tests and blood tests for fetal pathology; the health of the unborn child often depends on the degree of seriousness of her attitude to the changed situation and the doctor's recommendations.

It is also important to take into account that the probability of having children with physical or genetic disorders remains even in healthy and young parents.

Today, approximately 5% of the total number of newborns have congenital or genetic abnormalities, the causes can be chromosomal, genetic, multifactorial. Diagnose all disorders early stages a special analysis for fetal pathology (screening) will help. Used for newborns

The probability of having a sick child increases with the following factors:

poor environmental conditions;
exposure to drugs, radiation, chemical and toxic substances;
abuse bad habits, addiction;
transmission of deviations to the child from the parent ( genetic diseases); marriages between relatives;
work in hazardous industries;
cases of unsuccessfully transferred earlier pregnancies, incl. stillborn children, repeated miscarriages, infertility of an unknown nature;
age up to 18 years and over 35 years;
diseases of an infectious nature in a future mother, disorders of the immune system and the endocrine system.

Varieties of genetic disorders in children

Genetic abnormalities are congenital and acquired, the former are most common, the most famous is Down's syndrome.

Other pathologies:

Edward and Patau syndrome- the baby dies in the first year of life;
Treacher Collins syndrome- a child is born with gross deformities of the face, hearing impairment, absence / curvature auricles, pathologies respiratory tract, violations of swallowing and eating;
angelman syndrome- does not differ in wide prevalence, is accompanied by epileptic seizures, developmental delays.

What it is

Every pregnant woman should go through certain procedures, which allows you to identify abnormalities in the development of the fetus. Many women in labor do not know the name of the analysis for pathology during pregnancy.

In medical language, a set of tests is called prenatal screening, it consists of two parts: a blood test for markers and an ultrasound.

Types of analyzes:

blood test for markers- the procedure allows you to identify markers of chromosomal abnormalities of the fetus, to establish the level of hCG, plasma protein A, estriol;
ultrasound- reflects physical anomalies in the development of the embryo, is carried out for more later dates 3 times (each trimester).

Material sampling

IN female body substances that penetrate into her circulatory system from the fetus or placenta come. A biochemical blood test taken from a vein for fetal deformity allows you to determine the concentration of these substances. Based on the data obtained, the specialist can draw a conclusion about the course of pregnancy, the development of the embryo.

When to get tested

Standard screening is carried out at 10-16 weeks in the 1st trimester of pregnancy, the combined analysis reveals β-hCG and PAPP-a. In the same way, ultrasound is performed, the examination is aimed at measuring the collar space of the fetus.

At what time is the analysis for fetal deformity indicated? shown at 15-20 weeks of the 2nd trimester, a re-analysis for fetal deformity is carried out in order to study biochemical markers.

A woman donates blood, a specialist does a triple test (according to the number of tests), as part of it, the level is examined, free estriol and α-fetoprotein. The procedure is absolutely safe, it allows you to identify abnormalities in the early stages of embryo development, all tests should be taken on an empty stomach.

Decryption

Deciphering is done by a geneticist, important role plays an assessment of risk factors. It should be noted that the ratio of the content of the studied biochemical markers changes. In the 1st trimester with Down syndrome, the concentration of PAPP-a is significantly reduced compared to the norm, β-hCG is increased.

In order to adequately interpret the results of the analysis for fetal pathology and maximize exact definition the probability of hereditary pathology, the results of the analyzes obtained during the first examination are necessarily taken into account.

To decipher the blood test for fetal pathology at 12 weeks, an invasive diagnosis is performed, it includes following procedures:

- study of placental cells containing similar embryonic genetic material (11-12 weeks);
amniocentesis- examination of amniotic fluid, carried out by puncture of the amniotic membrane (15-16 weeks);
cordocentesis- analysis of blood taken from the umbilical cord (after 20 weeks);
placentocentesis- examination of the placenta (12-22 weeks).

Carrying out the above studies allows you to collect together accurate genetic information about the embryo and its condition. Ultrasound in the 2nd trimester (20-22 weeks) is the most accurate analysis for deformity during pregnancy, it allows you to diagnose any developmental disorders of the child.

Analysis accuracy

Often the question arises, what is the name of the analysis for deformity during pregnancy, how accurate is the analysis during pregnancy for pathology. Conducted at 12-16 weeks, tests for fetal pathology during pregnancy can detect fetal developmental disorders with a probability of up to 90%.

False positive results are fixed only in 6% of cases, when conducting a triple test, the accuracy is 85-90% to 5%. Biochemical analysis blood for chromosomal pathologies during pregnancy allows you to identify the likelihood of abnormalities in chromosomal development.

More detail is shown only on the condition that subsequent analyzes reflect similar results.

If tests for pregnant women for the detection of deformities have discrepancies, a recheck is carried out. Negative result Ultrasound combined with positive screening indicates 5-6% of those same false-positive cases.

It is also important to consider that an ultrasound examination can be done incorrectly, in such cases, an ultrasound scan is performed in another medical institution.

Parents should also take into account that the results of a pregnant woman's blood test for fetal pathology do not replace the diagnosis, they only warn of the risk of fetal developmental disorders. At increased risk, invasive diagnostics is generally safe, the risk of complications after it is 1-2%.

What to do when diagnosing pathology in the fetus

When anomalies incompatible with life are confirmed, termination of pregnancy is recommended, in other cases the decision is made by the woman.

Thanks to modern advances in medicine, most intrauterine pathologies can be corrected, complex heart defects, for example, are eliminated almost immediately after the birth of a child, science is powerless so far only in front of hereditary diseases.

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