Carrying a pregnancy once or twice in her life, a woman has a completely different attitude to this once "normal" state. Any failure (frozen pregnancy, spontaneous miscarriage) is of great importance. Every family planning a child, every woman who carries a baby under her heart is concerned about his health and usefulness. Therefore, more and more families are consulted with geneticists in advance, before the birth of children, with all responsibility preparing to become parents.

According to statistics, at least 5% of children are born with hereditary diseases and congenital malformations. Not a single married couple is insured from the birth of a sick child, and even healthy parents (unfortunately) may have a child with a congenital defect or hereditary disease. The problem is that there is always a possibility of the appearance of "fresh" mutations in the germ cells of the parents, the "transformation" of normal genes into pathological ones.

Medical genetic counseling and methods of prenatal (prenatal) diagnostics help to plan pregnancy and prevent the birth of a child with severe hereditary diseases.

Who needs to consult genetics when planning a pregnancy, necessarily before its onset?

There is such a thing as genetic risk groups. These groups include:

Married couples with hereditary family diseases;

Consanguineous marriages;

Women with an unfavorable history: having repeated miscarriages, stillbirth, infertility without an established medical cause;

Exposure to future parents of unfavorable factors: radiation, prolonged contact with harmful chemicals, the use of teratogenic drugs during conception, i.e. causing fetal deformities, action;

Women under 18 and over 35 and men over 40, because at this age, the risk of mutations in genes increases.

Thus, almost every second couple (more and more often women give birth after 35, doctors diagnose infertility, and the first pregnancies end in miscarriages) should consult a geneticist when planning a pregnancy.

Should other couples be consulted by a geneticist?

At the moment, the number of hereditary diseases transmitted in accordance with Mendel's laws is several thousand. And every year over a hundred new diseases are discovered. Therefore, it is clear that it is unrealistic even theoretically to fully foresee the presence of genes in someone's body that encode all the variety of hereditary diseases. Therefore, a geneticist's job is to manipulate probabilities. One hundred percent Guarantee as such does not exist in nature. But clarification of the degree of risk - high, medium or low - is absolutely necessary for planning preparation for pregnancy, as well as the volume of antenatal studies of the condition or genotype of the fetus.

That is why a visit to a geneticist is not superfluous for anyone. That is why in developed countries this is a rather popular type of medical care, despite the high cost (on average, 1 hour of medical genetic counseling in the United States, for example, costs about $ 200). Laboratory examination is also distinguished by a high cost.

Medical genetic counseling in planning pregnancy

In the course of medical genetic counseling, the doctor studies the pedigree of each specific family, as well as conditions that can be potentially dangerous for the unborn baby: diseases of future parents, drugs used, living conditions, ecology, profession - to exclude the impact of a possible adverse factor.

Further, if the geneticist deems it necessary, he will prescribe an additional examination to plan your pregnancy. For some, this will be a general clinical examination: biochemical blood tests, conclusions of a therapist, endocrinologist, neuropathologist. For someone - a special examination: the study of the karyotype, i.e. the quantity and quality of chromosomes of future parents. This method is called cytogenetic. In some cases (consanguineous marriages, miscarriage, infertility), a special genetic test called HLA TYPING is performed.

After analyzing your pedigree, the possible impact of harmful factors, studying the test results, the geneticist makes an individual genetic prognosis of the health of the unborn child, i.e. determines the risk of developing certain hereditary diseases and gives specific recommendations that will help parents when planning a pregnancy. Low risk - less than 10% means a healthy baby is born. The average risk - 10-20% indicates the possibility of giving birth to both healthy and sick children. In this situation, prenatal (ultrasound, chorionic biopsy, etc.) diagnosis during pregnancy is necessary. The high risk gives rise to recommendations for this couple either to abstain from pregnancy altogether, or to use a donor egg or sperm in the IVF program. Those. even with an average and high risk, there is the possibility of having a healthy baby.

When is it necessary to consult a geneticist in early pregnancy?
Early pregnancy is the most important and vulnerable period of fetal development. Various unfavorable situations can potentially disrupt the development of the organs of the unborn child. Patients are worried about how it will affect the development of the child and whether it is necessary to have an abortion if they are inadvertently in the early stages of pregnancy:

Sick with influenza, SARS, rubella, chickenpox, herpes, hepatitis, HIV-infected, etc.

Took medications, the annotations of which indicated "contraindicated in pregnancy";

They took alcohol, drugs, smoked (“drunken conception” - how dangerous is it?);

Teeth were treated with X-ray examination, fluorography was done;

We sunbathed, rode horseback, did mountaineering, diving, dyed our hair, did piercings, etc.

Laboratory diagnosis of malformations during pregnancy

And now the desired pregnancy has come. Is it possible to find out in the early stages if everything is in order? Modern medicine answers this question positively. At the disposal of obstetricians-gynecologists and geneticists, there are many diagnostic methods that make it possible to judge with a high probability the presence of malformations even when the child is in the womb. The chances of accuracy are increasing thanks to advances in ultrasound technology and laboratory diagnostics. And in recent years, screening research methods have been used more and more widely. Screening is a mass screening study. It is carried out for all pregnant women to identify the risk group. Why is it being held for everyone? Because statistics show that among mothers who gave birth to children with Down's disease, only 46% were over 35 years old. And only 2.8% had a history of the birth of children with chromosomal diseases or developmental defects. This proves once again that chromosomal pathology is the lot not so much of patients at risk as of young, uncomplicated families that do not have any diseases.

Screening methods include the determination of biochemical markers (BM) in the mother's blood serum and ultrasound of the fetus. These BMs in the first trimester are pregnancy-related plasma protein A (PAPP-A) and human chorionic gonadotropin (hCG). In the second trimester, these BMs are alpha-fetoprotein (AFP), hCG and estriol. In the first trimester, BM examination is performed from 8 to 12-13 weeks of pregnancy (early prenatal screening), in the second - from 16 to 20 weeks of pregnancy (late prenatal screening or triple test).

AFP is the main component of the blood of the developing fetus. This protein is produced by the liver of the fetus, excreted in the urine into the cavity of the ovum, absorbed through the fetal membranes and enters the mother's blood. By examining the blood from the mother's vein, one can judge its quantity.

It must be said that an increase or decrease in the amount of AFP by a factor of 2.5 or more in comparison with the norm is significant for diagnostics. So, for example, with anencephaly (absence of the brain), this indicator increases 7 times!

HCG is a protein produced by chorionic cells, i.e. the shell of the ovum. It is produced in the body of women from the 10-12th day after conception. It is his definition that allows you to confirm the onset of pregnancy with a test at home. The reaction on the dough strip is qualitative, i.e. indicates the presence or absence of this hormone. Its quantitative determination allows one to judge the course of pregnancy: for example, with an ectopic or non-developing pregnancy, the rate of increase in hCG does not correspond to the norm. Also, a change in this hormone may indicate the chromosomal pathology of the fetus.

Estriol begins to be produced in the liver of the fetus, and subsequently in the placenta. By the concentration of this hormone, one can judge the condition of the fetus. Normally, estriol levels rise throughout pregnancy.

But a change in the level of biochemical markers (BM) does not necessarily indicate fetal pathology. It can change in various obstetric situations and maternal diseases. For example, the amount of (BM) may decrease in overweight pregnant women, in women who smoke, with diabetes mellitus, with placental insufficiency. With hormonal treatment during pregnancy, after IVF, pregnancy with twins, BM levels may increase. Also, a change in the level can be with a threat of miscarriage and a low location of the placenta. Taking hormonal drugs (dyufaston, utrozhestan, dexometasone, metipred), antispasmodics (no-shpa, suppositories with papaverine, etc.) also affects the level of BM. And even race can affect the number of BM.

BM indicators are very often expressed in MoM. Normal values ​​of BM levels are in the range of 0.5-2.0 MoM. The individual risk of having a child with a chromosomal abnormality is calculated using a computer program, taking into account the gestational age, the patient's age and factors that can change the level of biochemical markers.

The threshold value is important here. This threshold - 1/250 means that among 250 women with the same data, there is 1 with fetal malformation, and the remaining 249 women have healthy babies. This threshold will divide all pregnant women into 2 groups: high risk (1/10 to 1/249) and low risk (1/251 onward). A high risk does not mean that your baby has certain diseases. This means the need for further examination.

It should be noted that there is a risk group, which was mentioned above, for which a consultation with a geneticist is indicated, despite good rates of prenatal screening.

Early prenatal diagnosis of fetal malformations during pregnancy

Early prenatal diagnosis (double test) has advantages over doing it in the second trimester because if a gross genetic pathology is detected, parents can decide to terminate the pregnancy before 12 weeks of pregnancy, and in case of minor deviations, repeat prenatal screening (triple test) from 16 weeks to 20 weeks of pregnancy in order to confirm or refute these deviations.

In some institutions, only AFP and hCG are tested, i.e. double test. I would like to emphasize that the diagnostic value of such a study is decreasing.

An integral part of prenatal diagnostics is ultrasound, which is highly informative and safe. As a screening, it should be used at 10-14 and 20-24 weeks of pregnancy. At 10-14 weeks, gross malformations of the fetus can be detected and the thickness of the collar space (TVP) can be measured. With TVP 3 mm or more, chromosomal breakdowns and fetal malformations are found in 30% of cases.

Ultrasound at 20-24 weeks of pregnancy allows you to exclude smaller malformations and deviations in the structure of certain organs.

Thus, only a combination of 2 methods (ultrasound and the study of biochemical markers) will help the doctor to timely make the correct diagnosis and refer the patient to a geneticist's consultation, who determines the need for invasive (i.e. intrauterine) methods, which are the final stages of medical and genetic examination. ...

Invasive methods for diagnosing malformations during pregnancy

These include chorionic biopsy, amniocentesis, placentocentesis, and cordocentesis. All these methods make it possible to exclude (or confirm) the chromosomal diseases of the fetus.

Chorionic biopsy is the collection of part of the chorionic cells (membrane of the ovum). It is carried out at 11-12 weeks of pregnancy.

Placentocentesis is taking placenta particles for examination. It is carried out at a later date - from 12 to 22 weeks of pregnancy.

Amniocentesis is a puncture of the anterior abdominal wall, uterus and amniotic fluid intake. It is performed at 15-16 weeks of pregnancy.

Cordocentesis - taking fetal blood from the umbilical cord. This test is done after 20 weeks of pregnancy.

All these procedures are performed with appropriate anesthesia, under ultrasound control and in very strict indications. Without sufficient evidence, these procedures are not performed.

So, the main task of medical and genetic examination during pregnancy is to identify chromosomal pathology or fetal malformations. This helps both the doctor and future parents to decide on further tactics. At the same time, you should remember that the doctor can offer one or another option for pregnancy management, but only the family should make the final decision.

In genetics, there is the concept of "general population risk". This risk is the best thing a consultant geneticist can say at an appointment. Such a general risk of congenital or hereditary pathology in the fetus is accompanied by pregnancy in the average married couple, without a burdened hereditary history, with a normal level of health. The value of the general population risk does not exceed 5 percent.

Happy pregnancy and easy delivery!

Pregnancy calendar.

Modern families approach the planning of procreation as seriously as possible. Preparing to acquire the most important and responsible status in life - a parent - requires the most scrupulous approach. Of course, we are talking about the health of expectant mothers and fathers. A comprehensive medical examination, which necessarily includes genetic tests, will help to understand this issue.

When planning a pregnancy, not only women are sent for their delivery, whom in the recent past doctors, whispering, called "old-born". Today, scientists in the field of genetic engineering have come to the conclusion that women over the age of 25 should also undergo such diagnostics.

Basic genetic tests for pregnant women

During gestation, it is extremely important to keep the placental lactogen under control. when planning a pregnancy, it will be able to determine its level - it is on it that the likelihood of spontaneous miscarriage, the further development of pregnancy, as well as its negative course in the form of fetal malnutrition or complete fading depend.

The definition of chorionic gonadotropin is also important. The level of this hormone allows you to determine pregnancy as early as possible. Such a genetic analysis when planning pregnancy (its price is not so high as to risk their own health and the life of the future baby) is carried out in blood serum.

The results of the study will help the obstetrician-gynecologist find out the degree of threat of termination of the expected pregnancy and the likelihood of complications in the uterus.

The role of geneticists in planning pregnancy

Genetic analyzes when planning pregnancy include other studies that allow to adequately assess the risks of various pathologies that may arise from the moment of conception and embryo formation. The cost of such studies is sometimes the only obstacle to their passage, but the benefits that they carry in themselves are almost impossible to overestimate.

The question of the usefulness of the future baby worries not only the mother, who is carrying him for 9 months under her heart. With hereditary diseases and intrauterine developmental anomalies, an average of every 20th child is born. To our great regret, not a single married couple will be able to insure their future descendant against the acquisition of any vices. It is a priori impossible to prevent this or that deviation at the level of DNA cells. In addition, a problem is also the fact that a genetic blood test during pregnancy planning, having shown acceptable results, sometimes does not guarantee a positive development of events: the likelihood of new mutations in the reproductive cells of the parental cells, including the risk of transition of normal genes into pathological , always remains.

Who should get genetic testing first?

The advantages of timely medical genetic counseling are assistance in planning pregnancy and preventing the birth of a baby with incurable pathologies.

Not many young families dreaming of becoming parents in the near future know what genetic tests they will have to undergo when planning pregnancy. In addition, certain groups of people need to be examined long before pregnancy without fail. These categories include men and women at risk of genetics, namely:

• married couples where at least one of the spouses has a history of serious diseases in the family;
• one of the spouses, in the history of the family tree of which there were cases of incest;
• women who had miscarriages, gave birth to dead babies or are diagnosed with infertility without a specific medical diagnosis;
• parents who have been in contact with radiation, harmful chemicals;
• women and men who have consumed alcohol or teratogenic drugs during conception, which can potentially cause fetal malformations.

At what age do you need to be tested for chromosomal abnormalities?

How much does a genetic analysis cost when planning pregnancy is known both to women under 18, those over the age of 35, and men who have crossed the 40-year threshold. As already mentioned, the risk of mutations in individual genes and DNA cells increases in arithmetic progression with each passing year.

Ideally, all couples should pass genetic tests when planning pregnancy.

Today, the multiplicity of hereditary ailments transmitted from generation to generation is the main reason for the need to undergo research for all young couples, without exception. In addition, modern genetics without stopping every year continue to discover more and more new diseases.

Genetic testing is an important step in planning a pregnancy

Naturally, it is impossible to foresee all genes that have the potential for mutation in the body of future parents. Not a single genetic analysis when planning a pregnancy can give one hundred percent guarantee that a particular married couple will have an absolutely healthy baby without hereditary abnormalities. Meanwhile, it is vital to clarify the degree of risk for theoretical and actual preparation for pregnancy.

So, potential parents turned to the medical genetic center for help. How will the specialists conduct the examination, and what genetic tests will they need to pass on a mandatory basis when planning a pregnancy? The curiosity of many will help satisfy the following.

Important points for geneticists

The first stage of the examination is medical and genetic counseling by a specialist, during which the doctor carefully and in detail examines the features of the pedigree in the family of each potential parent. The factors of increased risk for the unborn child deserve special attention of medical geneticists. They represent:

• genetic and chronic diseases of mom and dad;
• medicines used by prospective parents;
• conditions and quality of life, living conditions;
• features of professional activity;
• environmental and climatic aspects, etc.

Oddly enough, but a significant role for geneticists are the answers to ordinary, familiar to everyone, blood and urine tests, the conclusions of some narrow-profile specialists (endocrinologist, neuropathologist, etc.). Often, experts prescribe a karyotype diagnosis to married couples. Determining the number and quality of chromosomes in expectant mothers and fathers is extremely important in the case of incestuous marriages, miscarriage of several pregnancies, diagnosed but unexplained infertility.

How much does a genetic test cost?

The cost of genetic analysis for planning pregnancy, called "HLA-Typing", in various Moscow medical genetic centers ranges from 5,000 to 9,000 rubles, depending on the breadth of the spectrum of the study of predisposition to pathologies.

The completed study will help the geneticist to draw objective conclusions about the likelihood of exposure to negative factors. Genetic tests when planning pregnancy will make it possible to draw up an individual, relatively accurate forecast about the health of the future baby. It is a study of this type that will help to say about the estimated risk of a child developing specific hereditary ailments. The doctor will be able to give useful recommendations that should become the basis for a couple who dream of becoming the parents of a full-fledged healthy toddler.

Risks of giving birth to genetically ill children

In addition, each analysis is endowed with a value that determines the risk in the presence of a particular predisposition. Genetic diseases planning pregnancy, or rather the likelihood of their occurrence in the future crumbs, are measured as a percentage:

1. With a low risk (up to 10%), parents have nothing to worry about. All analyzes indicate that this married couple will have a healthy child in all respects.
2. With an average indicator (from 10 to 20%), the risk increases, and the possibility of having a sick baby is practically equated to the probability of a full-fledged child. Such a pregnancy will be accompanied by careful prenatal monitoring of the carrying woman: regular ultrasound, chorionic biopsy.
3. With high risks (from 20%), doctors will recommend that a married couple refrain from conceiving and prevent pregnancy. The likelihood that a baby will be born with a genetic disease is much higher than the chances of having a healthy baby. As an alternative solution in this situation, specialists can offer the couple to use or sperm in accordance with the IVF program.

Research early in pregnancy

Parents should not despair in any case. The chances of having an absolutely healthy baby remain even at high risk. To understand what genetic analysis gives when planning pregnancy, you should pay attention to laboratory diagnostic measures for malformations at the initial stages.

Almost from the moment of the onset of the long-awaited pregnancy for many parents, you can find out if everything is in order with the fetus? You can find out if your baby has any hereditary genetic diseases in utero.

Methods for genetic diagnosis of pregnant women

Doctors are capable of using many techniques and techniques for objective diagnosis of a pregnant woman and a fetus. Indeed, the presence of defects and developmental anomalies can be judged long before the baby is born. With each year of the progression of ultrasound and laboratory technology, the chances of accuracy increase. In addition, in the past few years, doctors have given priority to diagnostic methods such as screening. It is a "large-scale" electoral survey. Screening is mandatory for all pregnant women.

Everyone needs to take genetic tests!

Why is it necessary to undergo genetic tests even for those who do not fall into risk groups? The answer to this question is due to disappointing statistics. For example, only half of children born with Down syndrome to mothers over the age of 35. Among the remaining half of women in labor, there are many young women who have not even reached the age of 25. In women who became mothers of children with chromosomal abnormalities, only 3% had an entry in the exchange card about the birth of previous babies with similar diseases. That is, there is no doubt that genetic diseases are not a consequence of the age of the parents.

Avoid undergoing tests to identify chromosomal abnormalities in the fetus or a predisposition to the occurrence of genetic abnormalities in the future, a not yet conceived baby should not be. To determine the presence of any diseases at an early stage of their development means to get ahead of the pathology. Given the possibilities of modern medicine, not to take such a step towards the long-awaited baby would be unfair and irresponsible in relation to him.

Planning for a future child is a crucial stage in the life of every family. Today, more and more couples prefer to approach this issue very seriously, undergo a comprehensive survey to assess reproductive capabilities.

One of the important steps in this process is geneticist consultation and related analyzes. This is necessary to minimize the risk of having a baby with inherited pathologies.

Unfortunately, at present, not everyone knows about the wide range of possibilities of medical genetics, however, it would be not prudent.

What is genetic analysis

Genetic analysis is a complex of data obtained in the process of observation, calculation and laboratory analysis in order to determine hereditary traits and study the properties of human genes.

• infections, chronic diseases, hormonal disruptions, incl. disorders of the endocrine system, many of which can be treated in advance, or their effect on the body of the future fetus can be corrected;
• lack of vitamins and minerals necessary for the correct formation of the organs and systems of the unborn child;
• the presence of genetic pathologies.

When is it required

There are a number of conditions under which genetic counseling becomes necessary, these are:

• the age of partners when a woman is under 18 or over 35, and a man is over 40. It is outside these age limits that the risk of gene mutation and the development of pathologies significantly increases;
• hereditary diseases, as evidenced by the chronic pathologies of close relatives, the birth of a previous child with congenital defects, previous miscarriages or stillborn children;
• viral infections transferred by a woman during conception or during pregnancy;
• consanguinity of spouses;
• one or both spouses have minor physical disabilities in development, or the work of one of them is associated with an increased level of harmful conditions.

Genetic analysis should be passed by both spouses, whose family is planned to be replenished, tk. the child receives the same number of chromosomes from each of them.

Where and from whom you can get a genetic analysis

To undergo an analysis for hereditary factors of future parents consultation of a geneticist is necessary. A couple, who presumably should not have pathologies, can only do with a conversation, during which a specialist, using the clinical genealogical method, will collect information about the pedigree and try to find out the presence of conditions that indicate hereditary syndromes.

The characteristics of the pedigree include data on abortions, miscarriages, childless marriages. As a result, the specialist draws up a graphic image, on which he then performs the analysis.

The difficulties in carrying out this analysis are associated with the lack of information in the majority of modern people about their own relatives beyond 2-3 generations. Also, the causes of death of a distant relative or newborn baby are not always known.

The most complete picture allows you to give a clinical examination. His must be prescribed with the slightest suspicion of pathology. In this case, the doctor will ask both spouses to pass cytogenetic and molecular biological tests. The study of chromosomes is carried out using karyotyping, and for genetic incompatibility - HLA typing.

Based on the results of the examination, the doctor issues a written opinion on the possibility of the existence of pregnancy risks in the conditions studied through theoretical calculations and clinical analyzes, and gives recommendations on planning conception.

In cases too serious risk genetic pathology, donor eggs or sperm may be recommended for use. However, the responsibility for the final decision rests with the spouses themselves.

How much to trust the survey results

Having completed a complete examination for genetic factors, it is possible getting a fairly complete forecast about the possibility of deviations in the unborn child due to the structure of chromosomes. Also, analyzes can identify among the spouses the carrier of genes capable of mutation, which can lead to the birth of a sick baby.

Measurements carried out by specialists provide a percentage result. It is possible to draw a conclusion about a high proportion of the probability of manifestation of genetic failures on the basis of an indicator exceeding 20%.

An indicator of less than 10% is the most favorable, indicating that there are no problems with genetics. The average degree of risk occurs at a rate of 10 to 20%. Despite any results obtained, they cannot be considered the final judgment.

In absolutely all cases, there is a possibility of fetal development according to an unforeseen pattern of genetic prognosis. The reliability of the results of this survey consists only in the possibility of identifying risks as factors of the likelihood of a favorable or unfavorable course of future pregnancy, as well as, if possible, reducing their negative role.

Video

The video below demonstrates the relevance of genetic analysis during pregnancy planning at the present time. Often, children are born in families who inherit a number of both less and more serious pathologies.

A timely genetic analysis, as well as a consultation with a geneticist, will help prevent the risk of developing many of them. Answers to the most frequently asked questions about whether it is possible to prevent the manifestation of dangerous pathologies in a child?

And what analyzes should be done before and during pregnancy in order to determine with the probability of favorable conditions for the birth of a baby will be given by the deputy director of the Medical Genetic Center of the Russian Academy of Medical Sciences, Doctor of Medical Sciences V.L. Izhevsk.

To date, the nature of genetic abnormalities has not yet been fully understood. Many of them are foreseeable. Therefore, in order to exclude genetic pathologies and their spread, genetic analyzes are carried out.

Who needs a geneticist consultation when planning a pregnancy?

In order to be calm about the course of your future pregnancy, for the normal development of the fetus and the health of your unborn child, it is best to undergo a genetic analysis even when planning a pregnancy, especially if:

• a woman cannot conceive or bear a child. A consultation with a geneticist and carrying out the necessary tests when planning a pregnancy will help to understand the reasons for this situation. For this, a blood test is taken from a man and a woman, and their chromosome sets are examined;
• a woman who decides to have a child is more than 35 years old, and the father of an unborn child is more than 40 years old (the older the parents, the higher the risk of developing gene mutations);
• have relatives;
• future parents are close relatives;
• the first child has congenital abnormalities.

Analysis for genetics when planning pregnancy

When planning a pregnancy, a geneticist first gets acquainted with the pedigree of the family, finds out the factors potentially dangerous for the unborn child associated with the diseases of his parents, the drugs they take, living conditions, and professional characteristics.

Then, if necessary, the geneticist can order an additional analysis for genetics before pregnancy. This can be a general clinical examination, including: blood tests for biochemistry, consultation with a neuropathologist, therapist, endocrinologist. Or, special analyzes for genetics can be carried out, associated with the study of the karyotype - the quality and number of chromosomes of a man and a woman when planning a pregnancy. In the case of marriages between blood relatives, infertility or miscarriage, HLA typing is performed.

After analyzing the pedigree, evaluating other factors, and the test results, the geneticist determines the risk of hereditary diseases in the unborn child. A risk level of less than 10% indicates the likelihood of having a healthy baby. The risk level is 10-20% - the birth of both a healthy and a sick child is possible. In this case, subsequently, it will be necessary to do an analysis for genetics already in a pregnant woman. The high risk of genetic abnormalities is the reason for the couple to abstain from pregnancy or to use donor sperm or eggs. But even with high and medium risk levels, there is a chance that the baby will be born healthy.

Planning a pregnancy involves going through a series of medical examinations to assess a couple's fertility. Genetic counseling and analyzes for genetics during planning, in turn, are designed to minimize the likelihood of having a child with any hereditary pathologies.

Few people know that most of the embryos with abnormalities and various genetic defects die at the earliest stages of pregnancy due to such a mechanism as natural selection. If not for this, then much more sick children would be born. Therefore, sometimes such painful situations for all planning women happen, such as a miscarriage or a frozen pregnancy.

Medical genetic counseling is not a mandatory examination, but at the same time it is a very desirable step towards the birth of a healthy child. Currently, most often, spouses who have encountered a habitual or are sent to a geneticist for examination. However, such a specialist should be visited with a number of other indications:

• The previous pregnancy ended in the birth of a still or seriously ill child with genetic defects, a child with a deviation in physical or mental development.
• Genetic hereditary diseases among relatives.
• Consanguinity of spouses.
• The age of women is up to 18 and after 35 years, and men are over 40, when the likelihood of gene mutations in germ cells is slightly higher, and the mechanism of natural selection is weaker.
• The spouses have minor physical developmental disabilities.
• One of the spouses is working in harmful conditions.
• In the anamnesis there are pregnancies that were interrupted in the early stages - spontaneous miscarriages, anembryonia, frozen pregnancy.

Heredity and genetics

Even at school, everyone learns that a person has 46 chromosomes in every cell of the body, which are made up of genes and carry genetic information. Sex cells (sperm and eggs) contain only half of the set - 23 chromosomes, so that as a result of the fusion of two such cells, the new organism receives a complete chromosome set - half from the father and half from the mother. For the emergence of any genetic disease in a new organism, one cell with an abnormal set of chromosomes may be enough. Moreover, violations of the chromosome set in germ cells can also form in people who do not have any deviations in the structure of chromosomes in all other cells of the body, as a result of the harmful effects of alcohol, cigarettes, viruses, drugs during the maturation of sperm and eggs. That is why planning couples are advised to refrain from all this for at least three months before the planned date of conception.

How is a consultation with a geneticist going?

Genetic screening takes place in several stages.

First, the doctor needs to collect anamnestic data for both spouses. He will ask about all relatives and their possible congenital diseases, draw up a genealogical chart or pedigree. The genealogical method allows you to establish the type of inheritance of the disease, if it exists in the genus, and to determine the possible risks of this pathology in future children according to genetic patterns. That is why one should not hide from a geneticist any data about his relatives that he may need to build such a scheme. This can be not only information about cases of genetic pathology, but also other necessary facts regarding the birth, life or death of relatives to compile a complete picture.

Secondly, further for a complete examination, cytogenetic and molecular biological analyzes, such as karyotyping of spouses, allowing to examine the chromosomes of both partners, or HLA-typing, if the doctor suspects that there is genetic incompatibility spouses.

And, thirdly, at the end of the consultation, a geneticist with full responsibility and objectivity gives a written opinion on the possible risks, which is made on the basis of all preliminary theoretical calculations and laboratory studies. Also, in the conclusion, the doctor is obliged to formulate recommendations for the further planning of the child.

It happens that the risk of having a child with a serious genetic pathology in one particular family is so high that recommendations can even be given on the use of donor eggs or sperm. In the end, the final decision always rests with the spouses. Even if the couple does not have any genetic problems, which happens most often, then you should not count Geneticist's appointment wasted time, because, in fact, such a consultation is necessary precisely to exclude the likelihood of any pathologies occurring.