It is quite understandable that when planning a future pregnancy, both expectant parents should be examined. The reason is simple - the genetic contribution of each parent to the child's genome is almost exactly 50%.
Some excess of the contribution of a woman is explained by the physiological characteristics of her gametogenesis. The egg cell contains mitochondria - organelles that have their own hereditary apparatus, which, like any DNA, is subject to a mutational process. For this reason, some diseases, called mitochondrial diseases, are transmitted exclusively through the female line.
As a rule, genetic tests are carried out once. You can perform them at any age. The genetic constitution of a person, like fingerprints, does not change throughout life. Repeated tests are prescribed only when there are doubts about the correctness of the results. previous studies.
Genetic examination of a married couple begins with a visit to a geneticist-clinician. He takes a history. The purpose of such an interview is to find out if the family belongs to a genetic risk group and to schedule, if necessary, a laboratory examination.
Relationship between spouses may be risk factors(even distant), problems with relatives (the birth of a sick child or cases of miscarriage), work associated with radiation, chemical production or other harmful factors. The obligatory studies carried out at this stage are, rather, of a general clinical nature. it
- a routine extended blood test;
- biochemistry;
- gynecological smear;
- HIV tests;
TORCH group infections (toxoplasmosis, rubella, cytomegalovirus, herpes, urogenital infections - ureaplasmosis, chlamydia, mycoplasmosis, etc.) have become routine practice. The most accurate method for this is the PCR method. Enough conditionally, genetic tests include the determination of the blood group and Rh factor of the parents, necessary to exclude a possible Rh-conflict during pregnancy.
What kind of examinations should be done before conceiving a child?
These tests are carried out according to specific indications, but it is quite possible to carry them out at the request of a married couple. They can be divided into two groups.
Views
Karyotyping
This is a cytogenetic study of the chromosome set of spouses. Indications for him:
- infertility of unknown origin or habitual miscarriage;
- the birth of a previous child with a chromosomal abnormality;
- anomalies of sexual development;
- Carriage of karyotype (chromosomal set) anomalies previously diagnosed in relatives.
Chromosomal abnormalities include inversions and translocations- changes in the structure of the chromosomes of one of the spouses. Although such regular abnormalities are present in every cell of the body, outwardly this situation does not manifest itself in any way.
Clinically, a person can be healthy. But in the course of gametogenesis, such a "carrier" produces eggs or spermatozoa that carry an excess or deficiency of chromosomal material. During fertilization, a zygote appears, carrying an initially unbalanced chromosome set. The consequences are sad - miscarriage or the birth of a child with severe pathology.
Reference: Contrary to popular belief, the age of future parents is NOT an indication for the study of the karyotype of spouses.
Indeed, for women after 30-35 years and for men after 40 years, the risk of having a child with trisomy (extra chromosome) increases exponentially. But the reason for this is the nondisjunction of chromosomes directly in the developing germ cells.
At the same time, the study of the karyotype, that is, the somatic cells of the peripheral blood is completely uninformative. But in this case, it is extremely important to carry out prenatal diagnostics - the study of the chromosome set of the developing fetus.
In general, cytogenetic analysis is a reliable and proven method, but its resolution is still limited.
Molecular-cytogenetic
This test combines the standard procedure for obtaining chromosome preparations and modern molecular methods of working with DNA.
The method is able to establish with great accuracy the nature of chromosomal rearrangements. and diagnose abnormalities that are inaccessible to classical cytogenetics. The need for such a precise analysis is specific to the situation.
DNA diagnostics
This is a group of methods using PCR (the principle of polymerase chain reaction). They are used to detect the carriage of both monogenic diseases (Huntington's chorea, achondroplasia) and multifactorial (diseases with a hereditary predisposition) - diabetes mellitus, rheumatoid arthritis, etc.
DNA sequencing method
This method has come into practice in the last decade. He directly determines the nucleotide sequence of DNA... It also detects mutations at the level of one base pair - point mutations within a single gene. The accuracy of this method is equal to the theoretically possible limit. Such a test is able to detect the carriage of monogenic diseases inherited according to Mendel's laws. Until very recently, there were no reliable laboratory diagnostic methods for this at all.
Specific methods
Otherwise, these methods are referred to as HLA typing methods. They allow you to determine how well (or not) the spouses are immunologically suitable for each other. The indications here are, as a rule, family infertility of unknown origin or cases of miscarriage that have already existed in the woman's anamnesis, which are not associated with either chromosomal abnormalities or gynecological reasons.
Modern research has shown that in some cases, the cause of spontaneous abortions, complicated pregnancies and the appearance of initially weakened children is the immunological conflict between the mother and the fetus.
With similar HLA phenotypes of spouses, the woman's body takes the developing fetus not for a normal embryo, protected by the placental barrier, but behind its own tissue, in which unwanted changes have occurred, and tries to reject it.
The genetic compatibility test is designed to predict the development of such a situation and take the necessary measures in time. Unfortunately, the disadvantages of this method are its high cost and insufficient information content.
Preparation for conducting
The spouses do not need any specific preparation. Externally the sampling procedure looks like an ordinary blood sampling from a vein.
Prior to this, it is advisable that the last meal occurs no later than 12 hours before the visit to the laboratory. If you neglect this simple recommendation, then the blood can be "chyle", that is, saturated with fat. This is not of great importance for chromosome analysis, where not the blood itself is examined, but the cell culture obtained from it, but it can interfere with DNA diagnostics or biochemical studies.
How to interpret the results?
It happens that spouses refuse to conduct genetic research, fearing, often without any reason, a terrible diagnosis. But the task of geneticists is not to make a diagnosis as an end in itself. Having found out the genetic constitution of the spouses, medicine of the XXI century is already able to take many necessary measures.
By the way, the frightening term "hereditary disease" is now out of date. It is customary to speak not about "hereditary", but about genetically determined diseases, which are quite realistic to prevent or treat. The interpretation of the results is in the competence of the geneticist., a clinician. He will collate the information received and give all the necessary recommendations.
Where to take it?
The specificity of genetic pathology is that many of its manifestations refer to orphan, that is, rare diseases. Therefore, their diagnosis is carried out in specialized centers in a few large cities.
But married couples can contact the city or regional medical genetic counseling, Family Planning Center or Marriage and Family Service. There, spouses can undergo examinations available in their region, or receive a referral to a specialized center.
This brief overview by no means exhausts all the possibilities that modern medical genetics has at its disposal. To spouses who think in advance about the health and well-being of children, I will tell you a secret - the future has already come.
Adrenogenital syndrome, CYP210HB 9 h.m.
In the course of the study, a search is being made for frequent mutations in the CYP21OHB9 gene, which cause a disruption in the synthesis of steroid hormones in the adrenal cortex, which causes the development of adrenogenital syndrome.
The emergence of isolated fetal malformations
Identification of individual characteristics in the main genes of the folate cycle enzymes to assess the likelihood of folic acid deficiency during pregnancy (it is recommended to evaluate in combination with an immunochemical test to determine the level of homocysteine).
Genes typing of the HLA class II system
Identification of individual characteristics at three loci of HLA class II genes to assess the predisposition to the development of certain autoimmune diseases, including during pregnancy.
Molecular genetic testing HLA-B27
Genotyping HLA-B27 (HLA class I). It can be used in the differential diagnosis of seronegative spondyloarthropathies, including ankylosing spondylitis.
Identification of combinations of genotypes at the gene loci of the HLA class II system. May be recommended to assess the genetic risk of celiac disease.
Determination of the genotype of the Rh factor
The test includes the study of the RHD gene - the Rh factor gene with the determination of heterozygous or homozygous carriage for the Rh factor. On the form of the result, information about polymorphisms obtained during molecular genetic research is given, with comments.
Determination of the genotype of the Rh factor (without describing the results by a geneticist)
The test includes the study of the RHD gene - the Rh factor gene with the determination of heterozygous or homozygous carriage for the Rh factor. A description of the results by a geneticist is not issued.
Expanded study of the genes of the hemostasis system (with a description of the results by a geneticist)
Expanded study of genes of the hemostasis system (without description of the results by a geneticist)
Identification of individual characteristics in 12 genes of the hemostatic system. Advanced profile. It can be recommended to assess the risks of developing increased / decreased blood clotting.
Thrombosis: expanded panel
Thrombosis: extended panel (without a description of the results by a geneticist)
Identification of individual characteristics in 6 genes of the hemostatic system to assess the presence of risk factors for the development of thrombosis and an increase in the level of homocysteine (genes of prothrombin, Leiden factor and enzymes of the folate cycle reactions).
Thrombosis - minimum: shortened panel
Thrombosis - minimum: abbreviated panel (without a description of the results by a geneticist)
Identification of changes in 2 main genes of the hemostasis system to assess the presence of risk factors for the development of thrombosis (genes of prothrombin and Leiden's factor).
Fibrinogen - gene
The analysis is aimed at investigating polymorphisms in the gene β-polypeptide of fibrinogen FGB, which may cause an increase in the risk of developing thrombophilic conditions. On the form of the result, information about polymorphisms obtained during molecular genetic research is given, with comments.
Fibrinogen - gene (without a description of the results by a geneticist)
The analysis is aimed at investigating polymorphisms in the gene β-polypeptide of fibrinogen FGB, which may cause an increase in the risk of developing thrombophilic conditions. A description of the results by a geneticist is not issued.
Hyperhomocysteinemia
Platelet hyperaggregation
The study of polymorphisms in the genes of integrin alpha-2 and platelet glycoprotein 1b is carried out to identify a genetic predisposition to early development of myocardial infarction, ischemic stroke, thromboembolism, as well as to assess the risk of thrombosis. On the form of the result, information about polymorphisms obtained during molecular genetic research is given, with comments.
Platelet hyperaggregation (without a description of the results by a geneticist)
The study of polymorphisms in the genes of integrin alpha-2 and platelet glycoprotein 1b is carried out to identify a genetic predisposition to early development of myocardial infarction, ischemic stroke, thromboembolism, as well as to assess the risk of thrombosis. A description of the results by a geneticist is not issued.
Platelet fibrinogen receptor
Determination of polymorphisms in the gene of the platelet fibrinogen receptor (β3-integrin) is performed to identify a hereditary predisposition to thrombophilic conditions. On the form of the result, information about polymorphisms obtained during molecular genetic research is given, with comments.
Platelet fibrinogen receptor (without description of results by a geneticist)
Determination of polymorphisms in the gene of the platelet fibrinogen receptor (β3-integrin) is performed to identify a hereditary predisposition to thrombophilic conditions. A description of the results by a geneticist is not issued.
Hyperhomocysteinemia (without a description of the results by a geneticist)
Identification of changes in the main genes of folate cycle enzymes to assess the presence of a tendency to hyperhomocysteinemia (it is recommended to evaluate in combination with an immunochemical test to determine the level of homocysteine).
Cardiovascular diseases
During the study, genetic risk factors for the development of arterial hypertension, atherosclerosis, coronary heart disease, myocardial infarction, ischemic stroke are identified.
Arterial hypertension (full panel)
Analysis of polymorphisms in genes ACE, AGT, NOS3 makes it possible to detect hereditary risk factors for the development of arterial hypertension. On the form of the result, information about polymorphisms obtained during molecular genetic research is given, with comments.
Arterial hypertension (full panel) (without a description of the results by a geneticist)
Analysis of polymorphisms in genes ACE, AGT, NOS3 makes it possible to detect hereditary risk factors for the development of arterial hypertension. A description of the results by a geneticist is not issued.
Arterial hypertension associated with disorders in the renin-angiotensin system
The test allows you to determine the presence of genetic risk factors for the development of arterial hypertension as a result of narrowing of the lumen of blood vessels and disturbances in the water-salt balance that occur in the presence of polymorphisms in the genes ACE, AGT. On the form of the result, information about polymorphisms obtained during molecular genetic research is given, with comments.
Arterial hypertension associated with disorders in the renin-angiotensin system (without a description of the results by a geneticist)
The test makes it possible to determine the presence of genetic risk factors for the development of arterial hypertension as a result of narrowing of the vascular lumen and disturbances in the water-salt balance that occur in the presence of polymorphisms in the ACE, AGT genes. A description of the results by a geneticist is not issued.
Arterial hypertension associated with disturbances in the work of endothelial NO-synthase
As a result of the analysis of polymorphisms in the NO synthase gene, it is possible to assess the genetic risk of developing arterial hypertension as a result of a violation of the tone of the vascular wall. On the form of the result, information about polymorphisms obtained during molecular genetic research is given, with comments.
Arterial hypertension associated with disturbances in the work of endothelial NO-synthase (without a description of the results by a geneticist)
As a result of the analysis of polymorphisms in the NO synthase gene, it is possible to assess the genetic risk of developing arterial hypertension as a result of a violation of the tone of the vascular wall. A description of the results by a geneticist is not issued.
Ischemic heart disease, myocardial infarction
The study makes it possible to identify hereditary risk factors for the development of thrombosis, arterial hypertension and atherosclerosis by analyzing polymorphisms in the genes ACE, AGT, ApoE, NOS3, ITGB3, ITGA2. On the form of the result, information about polymorphisms obtained during molecular genetic research is given, with comments.
Ischemic heart disease, myocardial infarction (without a description of the results by a geneticist)
The study makes it possible to identify hereditary risk factors for the development of thrombosis, arterial hypertension and atherosclerosis by analyzing polymorphisms in the genes ACE, AGT, ApoE, NOS3, ITGB3, ITGA2. A description of the results by a geneticist is not issued.
Ischemic stroke (without a description of the results by a geneticist)
Ischemic stroke
Genetic risk factors for thrombosis and ischemic stroke. Analysis of the presence of polymorphisms in the genes of platelet glycoproteins and fibrinogen.
Crohn's disease
The test is used in the diagnosis of Crohn's disease, to determine the prognosis of the severity of the course of the disease and the risk of complications. The study is also used for the differential diagnosis of Crohn's disease with ulcerative colitis and as a prognostic test in relatives of patients with Crohn's disease.
Oncological diseases associated with environmental toxins
The study includes the identification of hereditary risk factors for the development of oncological diseases under the influence of a toxic load by analyzing the presence of polymorphisms in the genes of the detoxification system.
Marker for the development of Ph'-negative chronic myeloproliferative diseases (CMPD): quantification of the ratio of normal and mutant alleles 617V / 617F of the JAK2 gene.
Study of the Janus kinase gene. It can be recommended before starting treatment for CMPD and to determine the effectiveness of the therapy.
Hereditary cases of BRCA-associated cancer in men (breast, pancreas, prostate cancer, testicular cancer), 2 genes: BRCA1, BRCA2 (no description of the results)
Hereditary cases of BRCA-associated cancer in men (breast, pancreas, prostate cancer, testicular cancer), 2 genes: BRCA1, BRCA2
Determination of the 8 most common mutations in the BRCA1, BRCA2 (Breast Cancer 1/2) genes associated with the development of BRCA-associated cancer in men.
Type 2B multiple endocrine neoplasia syndrome
Type 2B multiple endocrine neoplasia syndrome belongs to a group of familial tumor syndromes associated with specific mutations of the RET proto-oncogene, which are detected during the study.
Gilbert's syndrome, UGT1A1
Genetic diagnosis of Gilbert's syndrome - unconjugated benign hyperbilirubinemia - is based on the study of possible mutations in the promoter region of the UGT1A1 gene.
Osteoporosis: Full Panel
Osteoporosis: full panel (without a description of the results by a geneticist)
Genetic risk factors for osteoporosis. Analysis of the presence of polymorphisms in the genes of the alpha-1 chain of the collagen type 1 protein and the calcitonin receptor.
Osteoporosis: an abbreviated panel
Genetic risk factors for osteoporosis. Analysis of the presence of polymorphisms in the genes of the alpha-1 chain of the collagen type 1 protein and the calcitonin receptor.
Osteoporosis: an abbreviated panel (without a description of the results by a geneticist)
Genetic risk factors for osteoporosis. Analysis of the presence of polymorphisms in the genes of the alpha-1 chain of the collagen type 1 protein and the calcitonin receptor.
Osteoporosis: vitamin D receptor
The study of genetic risk factors for the development of osteoporosis is carried out with a burdened family history of diseases of the bone apparatus, as well as in the presence of disorders of mineral metabolism. On the form of the result, information about polymorphisms obtained during molecular genetic research is given, with comments.
Osteoporosis: Vitamin D receptor (not reported by a geneticist)
The study of genetic risk factors for the development of osteoporosis is carried out with a burdened family history of diseases of the bone apparatus, as well as in the presence of disorders of mineral metabolism. A description of the results by a geneticist is not issued.
Folic acid metabolism
Folic acid metabolism (without a description of the results by a geneticist)
Identification of individual characteristics in the main genes of folate cycle enzymes to assess the presence of a tendency to hyperhomocysteinemia (it is recommended to evaluate in combination with an immunochemical test to determine the level of homocysteine).
Hereditary hemochromatosis, type I. HFE
Identification of the 2 most common mutations in the HFE gene to assess the risk of developing type 1 hemochromatosis. Recommended for detecting an increase in the concentration of ferritin and% saturation of transferrin with iron in the blood serum.
Description of the results of the genetic test of the 1st category of complexity (No. 7201BZ, 7611BZ, 7014BZ, 7030BZ, 125GP / BZ, 7207BZ)
Description of the results of the genetic test of the 2nd category of complexity (No. 118GP / BZ, 121GP / BZ, 123GP / BZ, 131GP / BZ, 141GP / BZ, 149GP / BZ, 150GP / BZ, 115GP / BZ, 152GP / BZ, 124GP / BZ, 154GP / BZ)
Description of the results of the genetic test of the 3rd category of complexity (No. 122GP / BZ, 129GP / BZ, 120GP / BZ, 137GP / BZ, 138GP / BZ, 153GP / BZ, 151GP / BZ, 110GP / BZ, 114GP / BZ, 140GP / BZ, 7661BZ, 7258BZ, 134GP / BZ, 135GP / BZ, 136GP / BZ)
Description of the results of the genetic test of the 4th category of complexity (No. 144GP / BZ, 143GP / BZ, 139GP / BZ, 145GP / BZ, 108GP / BZ, 19GP / BZ)
Warfarin: extended dose adjustment panel
The analysis of polymorphisms in the genes VKORC1, CYP2C9, CYP4F2, GGCX, which are genetic markers that determine the decrease in clinical efficacy when using warfarin, is being carried out.
Hydralazine and procainamide
The test includes analysis of polymorphisms in the NAT-2 gene, which indicates the presence of hereditary factors of increased risk of developing lupus-like syndrome and hepatotoxicity when taking cardiotropic drugs.
Isoniazid
The test includes an analysis of polymorphisms in the NAT-2 gene, which indicates the presence of hereditary factors of increased risk of developing polyneuritis when taking isoniazid, associated with a violation of its metabolism.
ACE inhibitors, fluvastatin, ATII receptor blockers
Analysis of polymorphisms in the ACE gene is necessary to predict the nephroprotective effect of angiotensin converting enzyme (ACE) inhibitors, a physiological regulator of blood pressure and water-salt metabolism in nondiabetic diseases. The study can determine the genetic markers of the effectiveness of atenolol in arterial hypertension with left ventricular hypertrophy or fluvastatin in coronary heart disease.
Irinotecan metabolism, UGT1A1
The study of the promoter region of the uridine diphosphate glucuronidase 1 gene with the analysis of polymorphisms in the UGT gene is used to establish the presence of a hereditary predisposition to an increased risk of developing adverse reactions when taking the anticancer drug irinotecan associated with a violation of its metabolism.
Penicillamine
Penicillamine is a drug from the group of detoxifying agents. Some variants of polymorphisms in the genes of the detoxification system of xenobiotics and carcinogens are associated with an increase in the clinical efficacy of this drug. The study is aimed at identifying genetic markers that potentiate clinical efficacy with the use of penicillamine.
Statins
Polymorphisms in the apolipoprotein E (ApoE) gene are a genetic marker for a decrease or increase in clinical efficacy with statins. This study can be used when choosing a diet, deciding whether to prescribe statins, lipid metabolism disorders, and also to determine the risk of cardiovascular diseases.
Beta-blockers. CYP2D6 gene. Pharmacogenetics.
Cytochrome CYP2D6 is involved in the metabolism of drugs (β-blockers, antiarrhythmics, analeptics, antidepressants and narcotic analgesics) used in the treatment of a number of cardiovascular diseases and mental disorders. The study of polymorphisms in the CYP2D6 gene makes it possible to identify people with reduced CYP2D6 activity, since such patients need to individually select lower doses of drugs.
Aspirin and Plavix
During the study, polymorphisms are analyzed in the ITGB3 gene, which is a genetic marker of resistance to antiplatelet therapy. The test results can be used to predict the effectiveness of antiplatelet therapy with aspirin and Plavix.
Uridine diphosphate glucuronidase, UGT1A1
The study of the promoter region of the uridine diphosphate glucuronidase 1 gene is carried out in the presence of clinical and / or laboratory signs of Gilbert's syndrome, when planning treatment with drugs with hepatotoxic properties, and also to determine the degree of risk of complications during irinotecan therapy.
Cytochrome CYP2C9
Analysis of the presence of polymorphisms in the cytochrome P450 gene is carried out to identify hereditary factors of detoxification disorders. CYP2C9 is involved in drug metabolism. With a decrease in the activity of cytochrome CYP2C9, the metabolism of drugs slows down, resulting in an increase in their concentration in the blood, which may be the cause of the development of undesirable reactions.
Fetal Rh factor. Detection of the RHD gene of the fetus in the mother's blood
Determination of the Rh-affiliation of the fetus by the mother's blood is used to choose the tactics of managing a Rh-negative pregnant woman. In a genotypically Rh-positive mother, it is impossible to obtain a result.
Today, you do not have to rely on chance, pregnancy can be planned in advance. For those girls who do not understand the essence of planning, it should be explained that it is a series of surveys. Each procedure that is carried out for planning a child helps to assess how ready young parents are for the birth of a baby. So consultation of a geneticist when planning a pregnancy helps to minimize the possibility of abnormalities in the baby at the genetic level.
If we return to such a topic as natural selection, then it is important to realize that most of the embryos that do not develop correctly die at the very beginning of pregnancy. If this did not happen, women would give birth to all sick children. Let a miscarriage or a frozen pregnancy be perceived by a woman as a sad event, but it allows in the future to give birth to a healthy baby. These are natural processes that are aimed at the good of the female body itself. In general, a geneticist during pregnancy is not an obligatory specialist who needs to be contacted. But it is he who allows you to treat pregnancy responsibly, gives you a chance to exclude genetic abnormalities during the planning period. This is a crucial step towards the birth of a healthy child. It is especially important to visit a specialist for those couples who are faced with infertility problems. Often, problems such as chronic miscarriage occur, this can also be a reason for visiting a specialist.
Reasons for turning to genetics when planning a pregnancy
It is clear that if there are certain problems, such as infertility, miscarriage, going to a specialist is simply not discussed. But there are other reasons, the presence of which prompts spouses to seek help from a geneticist:
- A dead child was born as a result of a previous pregnancy.
- The child was born with serious illnesses, there are deviations of the physical and mental plans.
- The spouses have a consanguinity.
- One of the spouses has known disabilities in physical development.
- During pregnancy, miscarriages occur, there were missed pregnancies, this can also be a reason for visiting a specialist.
- Work in conditions harmful to the body.
- Future parents or close relatives have genetically transmitted diseases.
- The woman is under the age of 35, and the partner is over 40 years old, this can lead to gene mutation, in this case the activity of natural selection is somewhat less.
What should be said about genetics when planning a pregnancy?
It is important to understand that genetics is a complex issue and only a professional geneticist can advise you when planning a pregnancy. Every schoolchild learns during training that in any cell of our body there is a certain number of chromosomes, which consist of genes. That is, they contain all the necessary information that parents transmit to us. And if ordinary cells contain 46 chromosomes, then in germ cells there are half of them. This is necessary in order for the germ cells to prepare for fusion.
For the occurrence of a disease of a genetic nature, it is enough to have only one cell, which has a non-standard set of chromosomes. This is exactly what a geneticist will be able to tell you during pregnancy. We must not forget that perfectly healthy people are also exposed to such problems. The reason for this can be the use of alcohol, smoking, the transfer of diseases during conception, as well as the use of a variety of medications. It is extremely important to give up bad habits at the time when the conception of a child is planned. Experts say that it is worth refraining from such a negative influence for three months.
What can you get from a consultation with a geneticist when planning a pregnancy?
It is worth remembering that the examination by a specialist takes place in several stages. So genetics before pregnancy involves the collection of data about the parents of the future crumbs, the collection of data about relatives. It is important to clarify information about whether there were any congenital diseases in the next of kin. Also, the specialist will be able to understand whether there were hereditary diseases in the family that are passed from generation to generation. If so, then you will have to assess the possibility of getting the disease. For this reason, you should not hide from a specialist any facts about relatives that you know. To get a complete picture, the doctor needs to get as much data as possible about your family, so talk about all the pathologies and diseases. Since the matter concerns your unborn child, you will need to tell about all the details of the birth and death of relatives. If the relative had a missed pregnancy, genetics will also help determine the likelihood of having a similar problem with you.
What will be required of you?
You will need to be tested for genetics during pregnancy, as well as undergo a series of examinations. These can be cytogenetic, molecular biological studies. Karyotyping is often prescribed, which helps to determine the state of the chromosomes of both partners. There is also HLA typing, it allows you to determine how compatible the expectant mom and dad are. Therefore, prepare yourself for the fact that you will not only have to donate blood for genetics during pregnancy, but also undergo other procedures. Based on the results of the examination, the specialist makes an official conclusion about the compatibility of the couple, about the presence or absence of risks of giving birth to a sick child. Such a result will be obtained based on the calculations that the doctor will make, as well as on the basis of the research carried out. It is from this specialist that you can get advice on planning pregnancy.
There are situations when there is a high risk of giving birth to an unhealthy child due to the presence of pathologies in a particular family. In such cases, experts strongly recommend using donor cells. In any case, the decision will depend only on the spouses, so you need to be prepared for different survey results. Genetic testing is necessary to ensure that your baby is born healthy.
Back in Soviet times, from the 1930s to the second half of the 1960s, genetics as a science was banned, and genetics were persecuted. In a socialist country, it was argued that its citizens could not have hereditary diseases, and talk about human genes was regarded as the basis of racism and fascism.
More than half a century later, ideas about genetics as a medical science and its role in human life have changed significantly, but genetic analysis, karyotyping (finding out the chromosome set of future parents), hereditary and chromosomal diseases and other concepts are still a “dark forest” for the common man. And such processes as pregnancy planning and consultation with a geneticist are scary for many married couples who want to have a baby or are already at the stage of pregnancy.
In fact, genetic analysis when planning a pregnancy can help avoid many problems associated with the inferiority of an unborn child.
What is genetic analysis?
Genetic analysis is an analysis by which you can see and understand how great the predisposition of the unborn child to genetic and other diseases is, as well as how external factors (ecology, nutrition, etc.) affect the development of the fetus in the womb.
A person has several tens of thousands of genes, and each of them plays an important role in his life. Not all genes are known to science today. It has even been established exactly which ones among them lead to mutations.
Each of us carries a unique set of genes that determine our characteristics in the future. Hereditary characteristics make up a set of 46 chromosomes. The child receives half of the chromosomes from the mother and half from the father. If any of them is damaged, then this is then displayed on the general condition of the crumbs.
To be calm about the normal course of pregnancy and fetal development, it makes sense to contact specialists to study the chromosome set, to do a genetic analysis. Molecular genetic studies will help determine the individual genetic characteristics of the fetus. By examining the individuality of genes, you can determine the risk of hereditary and other diseases in your offspring.
Doctors advise to carry out genetic analysis even during pregnancy planning, because then the chances of avoiding problems are much greater. But, as a rule, a woman turns to geneticists with a request for consultation already during pregnancy on the direction of a doctor or (less often) of her own free will.
When is genetic testing required when planning a pregnancy?
Medical genetic consultation is required if:
- the age of a woman is more than 35 years, and a man is more than 40 (this is the age when the risk of developing mutations and pathologies increases);
- the family has hereditary diseases;
- parents of the unborn child are close relatives;
- the first child was born with development;
- before the pregnant woman had miscarriages, stillbirth children;
- during conception or during pregnancy, harmful factors affected the fetus;
- during pregnancy, a woman had an acute viral infection (ARVI, rubella, flu);
- a pregnant woman is at risk based on the results of a biochemical or ultrasound examination.
Consultation with a geneticist
An important step for parents-to-be is to see a geneticist. A presumably healthy couple can simply talk to a geneticist, but often there are serious reasons for this consultation.
In the first case, a geneticist uses the clinical genealogical method, when he collects information about the pedigree and tries to determine as much as possible whether there were any conditions caused by hereditary syndromes. The pedigree includes information about miscarriages, abortions, childless marriages, etc. After collecting all the data, a graphic representation of the pedigree is made, and then the geneticist conducts an analysis.
The problem with the effectiveness of such research is that we, as a rule, do not know our relatives beyond the second or third generation. Sometimes people are unaware of what a distant relative or a newborn baby in the family died from. Further tactics of the doctor depends on how complete the clinical and genealogical analysis will be. In one case, only such an analysis will be enough to make a prognosis for the offspring, in the other, studies of the chromosome set of future parents and other genetic studies will be needed.
Methods for conducting genetic research:
- non-invasive research method
Non-invasive (traditional) examination methods - ultrasound examination and biochemical blood test.
An ultrasound examination is performed for a period of 10-14 weeks. During the examination, an ultrasound scan can show a congenital pathology in the baby. In the early stages of pregnancy, a biochemical blood test is also taken. With the help of such an analysis, it is possible to suggest hereditary or chromosomal pathology. A repeated ultrasound scan for a period of 20-24 weeks should be done if, after the tests performed, there are suspicions of abnormalities in the development of the fetus. In this way, minor malformations can be detected.
- invasive research methods
Invasive examination methods - amniocentesis, chorionic biopsy, placentocentesis, cordocentesis.
Invasive methods are prescribed if fetal pathologies are suspected. Such examinations make it possible to identify 300-400 out of 5000 genetic pathologies.
Amniocentesis- study . A pregnant woman is punctured with a thin special needle in the uterus to collect amniotic fluid. Amniocentesis is prescribed for 15 to 18 weeks.
Chorionic biopsy- study of the cells from which the placenta will form. When conducting such an analysis, the doctor makes a puncture into the abdominal cavity or takes material through the cervix.
Placentocentesis- samples of cells from the placenta that contain fetal cells. Placentocenosis is prescribed in late pregnancy (in the second trimester) if a woman has had an infectious disease during pregnancy. During the procedure, general anesthesia is given.
Cordocentesis- puncture of the umbilical cord blood of the fetus, which is taken through the uterine cavity. Cordocentesis is prescribed after the 18th week of pregnancy.
Due to this type of examination, it is likely that a woman may experience complications. Therefore, the genetic analysis of the pregnant woman and the fetus is carried out in a day hospital under ultrasound control and under the supervision of specialists. To prevent possible complications, the doctor may prescribe medication.
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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, who 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 a diagnosis.
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 tests 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 20 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 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 a pregnancy. In addition, certain groups of people need to be examined well 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 that can potentially cause fetal malformations.
At what age do you need to be tested for chromosomal abnormalities?
How much does genetic analysis cost when planning pregnancy is known both to women under 18, those over 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 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 karyotype diagnostics 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 allow you to make an individual, relatively accurate forecast about the health of the future baby. It is a study of this type that will help tell about the estimated risk of a child developing specific hereditary ailments. The doctor will be able to give useful recommendations, which should become the basis for a married 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:
- 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.
- With an average indicator (from 10 to 20%), the risk increases, and the possibility of having a sick baby is practically equal 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.
- With high risks (from 20%), doctors will recommend a married couple to refrain from conception 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 every year of the progression of ultrasound technology and laboratory research, 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 child who has not yet been conceived 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.