How long does it take for Down syndrome to be detected? Late application analysis

29.09.2019

Every pregnant woman worries about the health of her baby. Future parents are especially concerned about various genetic diseases, in particular Down syndrome, signs that have become easy to identify during pregnancy.

Down syndrome is a genetic disorder in the human body that occurs at the stage of conception. The anomaly received its name thanks to the British doctor John Langdon Down in 1866, but the genetic interpretation of the syndrome was given by the French geneticist Jerome Lejeune in 1959.

A genetic deviation occurs at the stage of conception of a new life during the fusion of two cells - a sperm and an egg. A fertilized egg must contain 46 chromosomes, of which 23 chromosomes belong to the father and 23 to the mother. Most often, an extra chromosome appears in 21 pairs of chromosomes and the total number is 47. The appearance of an extra chromosome is considered an accident. This form of the syndrome is called “trisomic” and occurs in 94% of cases. This type of disease has the most pronounced signs of abnormalities:

Mongoloid eye shape;
small ears;
deformed bridge of the nose;
mental retardation;
defects in the development of internal organs;
weak immunity;
weak muscle tone, etc.

In exceptional cases (about 4%), the genetic disorder is inherited - this is the translocation type of Down syndrome. In this case, 21 pairs of chromosomes are shifted to other chromosomes, but in general they do not differ significantly from the previous form. If translocation Down syndrome is present in the father, then the probability of developing the disorder is 3%, if in the mother it is 10-15%.

There is also mosaic Down syndrome, which is caused by the absence of an extra chromosome in some cells of the body and is very rare, occurring in about 2% of those born with the disorder. This form is considered the easiest, because. genetic disorders affect only certain organs and tissues of the body. Due to this, difficulties arise in uterine diagnosis of the disease. Children born with mosaic Down syndrome have normal appearance and intelligence.

According to statistics, every 700 pregnancies have Down signs. The presence of the syndrome does not depend on the lifestyle and rhythm of life of the future parents, region of residence and other factors. The main prerequisite for the birth of a baby with this disease is the age of the parents. The mother of a special baby can be a woman under the age of 20 or over 40. The age of the father also introduces risks if his age is close to 45 years. This is due, first of all, to a decrease in the productivity of the reproductive system, namely the ability of germ cells to divide. Another significant factor is the age of the future grandmother on the mother’s side, i.e. The older the future grandmother, the greater the likelihood of the child having the syndrome.

Parents also at risk include:

one of the parents has a hereditary history of translocation Down syndrome;
one of the parents is a twin (identical);
parents are close relatives.

How is Down syndrome diagnosed during pregnancy?

Today, Down syndrome is diagnosed during pregnancy. The following methods exist:

ultrasound examination at 10 - 13 weeks of pregnancy;
maternal blood test;
chorionic villus biopsy;
amniocentesis.

Every woman expecting a baby is required to undergo an ultrasound examination of the fetus at 10-13 weeks of pregnancy in Russia. The main indicators indicating the presence of developmental deviations: the thickness of the collar zone, anomalies of the nasal bones and deviations in the development of all systems of the baby’s body.

The thickness of the collar space is a measure of the space between the skin and future muscles around the cervical spine.

The presence of chromosomal abnormalities will be indicated by an increase in this zone by more than 3 mm. It is important to conduct the study within the specified period, because from the 14th week of pregnancy it becomes impossible to measure this space. The abnormality of the nasal bones is expressed in their absence, because in an embryo with a chromosomal pathology, the process of bone formation occurs much later.

Identifying abnormalities in the development of a baby’s body systems involves screening internal organs and blood flow. Children with Down syndrome have congenital heart defects, dilation of the renal pelvis, echogenicity of the intestines, vascular and circulatory diseases, and a deformed skeleton.

A mother's blood test is done to measure hCG and AFP levels. The level of human chorionic gonadotropin is detected up to 13 weeks of pregnancy.

Human chorionic gonadotropin is a hormone that is secreted by the female body after a fertilized egg attaches to the uterus.

The maximum hCG is observed at 10 weeks - from 20,000-95,000. With Down syndrome, this figure almost doubles, and in the absence of pathologies it varies from 20,000 to 90,000. It is important to know that an increased hCG rate does not necessarily indicate pathology; it can increase several times during multiple pregnancies.

Alphafetoprotein or AFP is a protein that is secreted by the fetal liver and gastrointestinal tract into the amniotic fluid.

This protein enters the blood of the expectant mother through the amniotic fluid. Before the baby's organs can produce the necessary protein, it will be produced by the mother's ovaries, until about the fifth week. AFP protects the embryo from being rejected by the mother's body.

The level of AFP is considered one of the main indicators of the presence of abnormalities in the development of the fetus, so its decrease indicates Down syndrome, and its increase indicates pathology of the fetal neural tube. The indicator is measured in medians (or MoM). It is recommended that an alpha-fetoprotein test be performed between 14 and 20 weeks of pregnancy.

There is also a non-invasive analysis of fetal chromosomes using a blood test from the mother. The blood of the expectant mother contains particles of DNA from the child in her womb. They get there by being secreted by the baby's organs into the amniotic fluid. The analysis takes no longer than two weeks, but it requires 10 ml of blood. This type of blood test is distinguished by its accuracy and is prescribed when pathology is detected or suspected during previous screening methods.

Amniocentesis is an invasive way to diagnose chromosomal abnormalities. It is performed by puncturing the pregnant woman’s abdomen or through the cervix. Amniotic fluid, placental particles, fetal skin and fetal blood are used for analysis. The analysis is considered the most reliable, but carries significant risks for the health of the expectant mother and baby. Amniocentesis increases the risk of miscarriage and infection of the fetus, so this procedure should be performed by a qualified doctor using the latest technology. Also, this procedure must be prescribed by an obstetrician-gynecologist and carried out only with the consent of the pregnant woman. The result will have to wait no more than four days.

Chorionic villus sampling is also performed by puncturing the pregnant woman's abdomen during an ultrasound, as with amniocentesis. I would like to highlight this procedure, because... here the fetus is not disturbed, and a small part of the chorion is taken for analysis.

The chorion is the membrane that surrounds the fertilized egg and separates it from the walls of the uterus.

The risks borne by the expectant mother are the same as those associated with amniocentesis. The result will also not take long to arrive, about 4 days.

In the fifth month of pregnancy, it is possible to accurately diagnose using ultrasound. During this period, all organs of the child are formed, and you can examine the appearance without any tests.

In general, I would like to say that any type of screening must be carried out in a timely manner. This will increase the accuracy of the analysis results and reduce some risks. In any case, no analysis can be 100% reliable. When carrying out procedures, many factors must be taken into account: the doctor’s qualifications, statistics on the reliability of the clinic’s test results, modern medical equipment, the absence of contraindications from the obstetrician-gynecologist, as well as the psychological state of the woman herself. In practice, it happens that screening studies indicate the presence of Down syndrome, but after birth they exclude it. Although, today, the percentage of erroneous results is insignificant, due to progress in medical research methods and medical equipment.

Only the mother should decide whether to carry her baby with developmental disabilities or not, unless there are other medical contraindications. Of course, raising a child with Down syndrome entails enormous responsibility and expends enormous amounts of parental energy. People with chromosomal abnormalities, as a rule, are not capable of reproductive function, are delayed in development, have many abnormalities in the functioning of internal organs, and even differ in appearance from their peers. It’s not for nothing that they are called “solar”, because... they also have positive qualities. Sunny children are very cheerful, kind, sweet and look at the world with different eyes. Down syndrome is not a death sentence. There are many examples of successful lives of people with this diagnosis. Among them are models, artists, actors and even managers of commercial and non-profit organizations.

Down syndrome- the most common chromosomal pathology. It occurs when, as a result of a random mutation, another chromosome appears in the 21st pair. Therefore, this disease is also called trisomy 21.

What does this mean? Every cell in the human body has a nucleus. It contains genetic material that determines the appearance and function of an individual cell and the entire organism as a whole. In humans, 25 thousand genes are assembled into 23 pairs of chromosomes, which in appearance resemble rods. Each pair consists of 2 chromosomes. In Down syndrome, the 21st pair consists of 3 chromosomes.

The extra chromosome causes characteristic symptoms in people: a flat bridge of the nose, Mongoloid eyes, a flattened face and back of the head, as well as developmental delays and reduced resistance to infections. The collection of these symptoms is called a syndrome. It was named after the physician John Down, who was the first to undertake its research.

The outdated name for this pathology is “Mongolism.” The disease was called so because of the Mongoloid shape of the eyes and a special fold of skin that covers the lacrimal tubercle. But in 1965, after Mongolian deputies appealed to the World Health Organization, this term is not officially used.

This disease is quite ancient. Archaeologists have found a burial place that is one and a half thousand years old. The structural features of the body indicate that the person suffered from Down syndrome. And the fact that he was buried in the city cemetery according to the same customs as other people indicates that the patients did not experience discrimination.

Babies born with 47 chromosomes are also called “Children of the Sun.” They are very kind, affectionate and patient. Many parents raising such children claim that their children do not suffer from their condition. They grow up cheerful and happy, they never lie, do not experience hatred, and know how to forgive. Parents of such babies believe that the extra chromosome is not a disease, but a feature. They are against children being called down or mentally ill. In Europe, people with Down syndrome study in regular schools, get a profession, live independently or start a family. Their development depends on individual abilities, whether the child was trained and what methods were used.

Prevalence of Down syndrome. One such child is born for every 600-800 newborns, or 1:700. But for mothers over 40 years old, this figure reaches 1:19. There are periods when there is an increase in the number of children with Down syndrome in certain areas. For example, in the UK over the past decade this figure has increased by 15%. Scientists have not yet found an explanation for this phenomenon.

In Russia, 2,500 children with Down syndrome are born every year. 85% of families refuse such babies. Although in Scandinavian countries parents do not abandon children with this pathology. According to statistics, 2/3 of women have an abortion after learning that the fetus has chromosomal abnormalities. This trend is typical for the countries of Eastern and Western Europe.
A child with trisomy 21 can be born into any family. The disease is equally common on all continents and in all social strata. Children with Down syndrome were born into the families of Presidents John Kennedy and Charles de Gaulle.

What parents of children with Down syndrome need to know.

Despite the delay in development, children are teachable. With the help of special programs, it is possible to increase their IQ to 75. After school, they can get a profession. Even higher education is available to them.
The development of such children proceeds faster if they are surrounded by healthy peers and raised in a family rather than in a specialized boarding school.
“Children of the Sun” are strikingly different from their peers in their kindness, openness, and friendliness. They are capable of sincere love and can create families. True, their risk of giving birth to a sick child is 50%.
Modern medicine can increase life expectancy to 50 years.
Parents are not to blame for their child's illness. Although there are age-related risk factors, 80% of children with Down syndrome are born to absolutely healthy women aged 18-35 years.
If your family has a child with Down syndrome, then the risk that the next baby will have the same pathology is only 1%.

Causes of Down syndrome

Down syndrome is a genetic pathology, which appears in the fetus at the moment of conception, when the fusion of the egg and sperm occurs. In 90% of cases, this occurs because the female reproductive cell carries a set of 24 chromosomes, instead of the required 23. In 10% of cases, the extra chromosome is passed on to the child from the father.

Thus, illness of the mother during pregnancy, stress, bad habits of parents, poor nutrition, and difficult childbirth cannot affect the appearance of Down syndrome in the child.

The mechanism of occurrence of chromosomal pathology. A special protein is to blame for the fact that one of the germ cells contains an extra chromosome. Its function is to stretch the chromosomes towards the poles of the cell during division, so that as a result each of the daughter cells receives one chromosome from the pair. If on one side the protein microtubule is thin and weak, then both chromosomes from the pair are pulled to the opposite pole. After the chromosomes in the mother cell have separated to the poles, a shell is formed around them, and they turn into full-fledged germ cells. With a protein defect, one cell carries a set of 24 chromosomes. If such a germ cell (male or female) is involved in fertilization, then the offspring develops Down syndrome.

The mechanism of neurodevelopmental disorders in Down syndrome. The “extra” chromosome 21 causes peculiarities in the development of the nervous system. These deviations underlie mental and mental development delays.

Cerebrospinal fluid circulation disorders. In the choroid plexuses of the ventricles of the brain, an excess amount is produced, and absorption is impaired. This leads to increased intracranial pressure.
Focal damage to the brain and peripheral nerves. These changes cause problems with coordination and movement and inhibit the development of gross and fine motor skills.
The cerebellum is small in size and does not perform its functions sufficiently. As a result, characteristic symptoms appear: weakened muscle tone, it is difficult for a person to control his body in space and control the movements of his limbs.
Cerebral circulation disorders. Due to weak ligaments and instability of the cervical spine, the blood vessels that support brain function are compressed.
Reduction in brain volume and an increase in ventricular volume.
Reduced activity of the cerebral cortex– fewer nerve impulses occur, which manifests itself in lethargy, slowness, and a decrease in the speed of thought processes.

Factors and pathologies that can lead to Down syndrome

Marriages between close relatives. Close relatives are carriers of the same genetic pathologies. Therefore, if two people had defects in the 21st chromosome or the protein responsible for the distribution of chromosomes, then their child has a high probability of Down syndrome. Moreover, the closer the degree of relationship, the higher the risk of developing genetic pathology.

Early pregnancies under 18 years of age.
In young girls, the body is not yet fully formed. The gonads may not function stably. The processes of egg maturation often fail, which can lead to genetic abnormalities in the child.

Mother's age is over 35 years.
Throughout life, eggs are exposed to various harmful factors. They negatively affect genetic material and can disrupt the process of chromosome division. Therefore, after 35 years, the expectant mother needs to undergo medical and genetic counseling in order to determine genetic pathologies in the child before birth. The older the woman, the higher the risk to the health of her offspring. Thus, after 45 years, 3% of pregnancies end in the birth of a child with Down syndrome.
Father's age is over 45 years.
As men age, the process of sperm formation is disrupted and the likelihood of abnormalities in the genetic material increases. If a man at this age decides to become a father, then it is advisable to first do a test to determine the quality of sperm and undergo a course of vitamin therapy: 30 days of taking vitamin E and minerals.
The age of the maternal grandmother at the time she gave birth to the child.
The older the grandmother was when she was pregnant, the greater the risk for her granddaughters. The fact is that all the mother’s eggs were formed during intrauterine development. Even before a woman is born, she already has a lifelong supply of eggs. Therefore, if the grandmother’s age exceeded 35 years, then there is a high risk that the mother of the sick baby will have an egg with the wrong set of chromosomes.
The parents are carriers of the translocation of the 21st chromosome.
This term means that in one of the parents a section of the 21st chromosome is attached to another chromosome, most often to the 14th. This feature does not manifest itself in any way externally and the person does not know about it. But such parents have a significantly increased risk of having a child with Down syndrome. This phenomenon is called “familial Down syndrome”. Its share among all cases of the disease does not exceed 2%. But all young couples who have a child with the syndrome are examined for the presence of translocations. This helps determine the risk of developing genetic disorders in subsequent pregnancies.

Down syndrome is considered random genetic mutation. Therefore, risk factors such as infectious diseases, living in an area with high levels of radiation, or consuming genetically modified foods do not increase the risk of its occurrence. The syndrome cannot cause severe pregnancy and difficult childbirth. Therefore, parents should not blame themselves for the fact that their child has Down syndrome. The only thing you can do in this situation is to accept and love the child.

Signs and symptoms of Down syndrome during pregnancy

Screening for genetic abnormalities during pregnancy

Prenatal screening is a set of studies aimed at identifying gross disorders and genetic pathologies in the fetus. It is administered to pregnant women registered at the antenatal clinic. Research allows us to identify the most common genetic pathologies: Down syndrome, Edwards syndrome, neural tube defects.

First, let's look at non-invasive examination methods. They do not require disruption of the integrity of the amniotic sac in which the baby is located during pregnancy.

Ultrasound

Deadlines: first trimester, optimally from the 11th to 13th week of pregnancy. Repeat ultrasounds are performed at 24 and 34 weeks of pregnancy. But these studies are considered less informative for diagnosing Down syndrome.

Indications: all pregnant women.

Contraindications: pyoderma (purulent skin lesion).

Interpretation of results. Possible Down syndrome is indicated by:

Underdeveloped nasal bones. They are shorter than in healthy children or completely absent.
The width of the fetal nuchal space exceeds 3 mm(normally up to 2 mm). With Down syndrome, the space between the neck bone and the surface of the skin on the fetal neck increases, in which fluid accumulates.
The humerus and femur are shortened;
Cysts in the choroid plexus of the brain; the movement of blood in the venous ducts is disrupted.
The iliac bones of the pelvis are shortened, and the angle between them is increased.
Coccyx-parietal size(distance from the crown of the fetus to the coccyx) at the first ultrasound is less than 45.85 mm.
Heart defects - abnormalities in the development of the heart muscle.

There are deviations that are not symptoms of Down's disease, but confirm its presence:

enlarged bladder;
rapid fetal heart rate (tachycardia);
absence of one umbilical artery.

Ultrasound is considered a reliable method, but in diagnosis much depends on the professionalism of the doctor. Therefore, if similar signs are found on an ultrasound, this only indicates the likelihood of the disease. If one of the symptoms is identified, then the probability of pathology is about 2-3%, but if all of the listed signs are detected, then the risk of giving birth to a child with Down syndrome is 92%.

Blood chemistry

In the first and second trimester, blood is taken from the mother for biochemical testing. It defines:

Human chorionic gonadotropin (hCG) a hormone secreted by the placenta in the body of a pregnant woman.
Pregnancy-associated protein A (PAPP-A). This protein is produced by the placenta during the initial stages of pregnancy to suppress the attack of maternal immunity towards the fetus.
Free estriol is a female steroid hormone produced in the placenta from a precursor hormone secreted by the fetal adrenal glands.
Alpha fetoprotein (AFP)- a protein produced in the liver and digestive system of the fetus to protect against the mother's immunity.

Deadlines:

First trimester from 10th to 13th week of pregnancy. Blood serum is examined for hCG and PAPP-A. This is the so-called double test. It is considered more accurate than blood testing in the second trimester. Its reliability is 85%.
Second trimester from 16th to 18th week of pregnancy. The level of hCG, AFP and free estriol is determined. This study was called triple test. Confidence 65%.

Indications. This examination is not mandatory, but it is recommended to undergo it in the following cases:

mother's age over 30 years;
the family has children with Down syndrome;
have close relatives with genetic diseases;
serious illness suffered during pregnancy;
previous pregnancies (2 or more) ended in miscarriages.

Contraindications: does not exist.

Interpretation of results.

Double test results in the first trimester:

hCG a significant excess of the norm (over 288,000 mU/ml) indicates a genetic pathology, multiple pregnancy, or incorrect gestational age.
RARR-A a decrease of less than 0.6 MoM indicates Down syndrome, a threat of miscarriage or a non-developing pregnancy.

Triple test results in the second trimester:

hCG more than 2 MoM indicates a risk of Down syndrome and Klinefelter syndrome;
AFP less than 0.5 MoM may indicate that the child has Down syndrome or Edwards syndrome.
Free estriol less than 0.5 MoM indicates that the fetal adrenal glands are not working enough, which happens with Down syndrome.

To correctly assess the situation, the doctor must have the results of both screenings. In this case, one can judge the dynamics of growth in hormone levels. The test results confirm the likelihood of having a child with a genetic pathology. But based on them, a diagnosis of “Down syndrome” cannot be made, since the results can be affected by various medications taken by a woman during pregnancy.

Based on the results of ultrasound and biochemical blood tests, a “risk group” is formed. It includes women who may have a child with Down syndrome. Such patients are referred for more precise invasive studies that involve puncture of the amniotic sac. These include amniocentesis, cordocentesis, and chorionic villus biopsy. For women who become pregnant before the age of 35, the study is paid for by the Ministry of Health, provided that the referral was given by a geneticist.

Amniocentesis

This is a procedure for collecting amniotic fluid (amniotic fluid) for research. Under ultrasound control, a special needle is used to make a puncture through the abdomen or vaginal vault and draw 10-15 ml of liquid. This procedure is considered the safest of all invasive examinations.

Deadlines:

from 8th to 14th week;
after the 15th week of pregnancy.

Indications:

Ultrasound results indicate the likelihood of Down syndrome;
the results of biochemical screening indicate chromosomal pathology;
one of the parents has a chromosomal disease;
marriage between blood relatives;
The mother is over 35 years old and the father is over 40 years old.

Contraindications:

acute or chronic diseases of the mother;
the placenta is located on the anterior abdominal wall;
the woman has uterine malformations.

Interpretation of amniocentesis results

Fetal cells are found in the amniotic fluid. They contain all the chromosomes. If a genetic analysis reveals three 21st chromosomes, then the probability that the child has Down syndrome is 99%. The test results will be ready in 3-4 days. But if the cells need more time to grow, then you will have to wait 2-3 weeks.

Possible complications of amniocentesis

The risk of miscarriage is 1%.
The risk of infection is 1% by amniotic fluid microorganisms.
After 36 weeks, labor may begin. In the later stages, any stimulation of the uterus or stress can cause premature labor.

Cordocentesis

Cordocentesis – procedure for testing cord blood. A thin needle is used to make a puncture in the abdominal wall or cervix. Under ultrasound control, a needle is inserted into the umbilical cord vessel and 5 ml of blood is taken for testing.

Deadlines: the procedure is carried out from the 18th week of pregnancy. Before this, the umbilical cord vessels are too thin to take blood samples. The optimal period is 22-24 weeks.

Indications:

genetic diseases in parents or their blood relatives;
there is a child in the family with a chromosomal pathology;
based on the results of ultrasound and biochemical screening, a genetic pathology was identified;
mother's age is over 35 years.

Contraindications:

maternal infectious diseases;
threat of miscarriage;
compactions in the uterine wall of the uterus;
maternal bleeding disorder;
bloody discharge from the vagina.

Interpretation of cordocentesis results

Umbilical cord blood contains cells that carry the chromosome set of the fetus. The presence of three chromosomes 21 indicates Down syndrome. The reliability of the study is 98-99%.

Possible complications of cordocentesis the risk of complications is less than 5%.

slow fetal heart rate
bleeding from the puncture site;
hematomas on the umbilical cord;
premature birth in the third trimester;
inflammatory processes that can lead to miscarriage.

Chorionic villus biopsy

A procedure for removing tissue samples from small finger-like projections on the placenta for further examination. A puncture is made in the abdominal wall and a sample is taken with a biopsy needle for study. If the doctor decides to do a biopsy through the cervix, then a thin flexible probe is used. The results of the study will be ready in 7-10 days. An in-depth analysis requires 2-4 weeks.

Deadlines: 9.5-12 weeks from the beginning of pregnancy.

Indications:

the age of the pregnant woman is over 35 years;
one or both parents have genetic or chromosomal pathologies;
during previous pregnancies, chromosomal diseases were diagnosed in the fetus;
According to the screening results, there is a high risk of developing Down syndrome.

Contraindications:

acute infectious diseases or chronic diseases in the acute stage;
bleeding from the vagina;
cervical weakness;
threat of miscarriage;
adhesive process in the pelvis.

Interpretation of chorionic villus sampling results

Cells taken from the chorion contain the same chromosomes as the fetus. A laboratory assistant studies chromosomes: their number and structure. If three chromosomes of the 21st pair are detected, the probability of Down syndrome in the fetus is close to 99%.

Possible complications of chorionic villus sampling

spontaneous termination of pregnancy with a puncture through the abdominal wall, the risk is 2%, through the cervix up to 14%;
pain at the site where the sample was taken;
inflammation of the membranes of the fetus - chorioamnionitis;
hematoma at the site of sampling.

Although invasive methods are quite accurate, they cannot give a 100% reliable answer as to whether the child is sick. Therefore, parents, together with a geneticist, must decide whether to undergo additional research, whether to terminate the pregnancy for medical reasons, or whether to save the child’s life.

Signs and symptoms of Down syndrome in a newborn

90% of newborns with Down syndrome have characteristic external signs. Such children are similar to each other, but have absolutely no resemblance to their parents. Features of appearance are inherent in the extra chromosome.

In 10% of newborns with pathology, these signs may be mild. At the same time, such appearance features may be present in healthy children. Therefore, a diagnosis of Down syndrome cannot be made based on one or more of the listed symptoms. The presence of chromosomal pathology can be confirmed only after genetic analysis.

Signs and symptoms of Down syndrome in children and adults

Children and adults with Down syndrome retain the characteristic external signs noticeable in newborns. But with age, other symptoms appear or become apparent.

How does a child with Down syndrome develop?

Several decades ago, it was believed that children with Down syndrome were a burden for parents and a burden for society. They were isolated in special boarding schools, where the children's development practically stopped. Today the situation is beginning to change. If parents are involved in the development of the child from the first months using special educational programs, then this allows the little person to turn into a full-fledged person: live independently, get a profession, start a family.

The state and public organizations provide comprehensive assistance to such families:

Local pediatrician. This person is responsible for your baby's health after leaving the maternity hospital. The doctor will tell you how to care for your baby and give you a referral for examination. Be sure to consult your doctors and take the necessary tests. This will help to promptly identify concomitant pathologies and begin treatment in a timely manner. After all, various diseases can aggravate mental and physical development delays.
Neurologist. This specialist monitors the development of the nervous system and will tell you how to help the child. He will prescribe medications, massages, physical therapy and physical therapy techniques to stimulate proper development.
Oculist will help to promptly identify vision problems that occur in 60% of children with Down syndrome. At an early age, it is impossible to determine them on your own, so do not miss a visit to this specialist.
ENT checks the child's hearing. These disorders can make speech and pronunciation problems worse. The first sign of hearing problems is that the child does not flinch from a sharp loud sound. The doctor will conduct an audiometric examination and determine whether your hearing is impaired. The adenoids may need to be removed. This operation makes it easier to breathe through the nose and keep the mouth closed.
Endocrinologist reveals disturbances in the functioning of the endocrine glands, especially the thyroid. Contact him if your child begins to get better, lethargy, drowsiness increase, feet and palms are cold, temperature is below 36.5, constipation becomes more frequent.
Speech therapist. Classes with a speech therapist will help minimize problems with pronunciation and speech.
Psychologist. Helps parents accept the situation and love their baby. In the future, weekly sessions with a psychologist will help the child develop properly and improve his skills. The specialist will tell you which methods and programs are more effective and suitable for your child.
Rehabilitation center for people with Down syndrome, Down Syndrome Association. Public organizations provide comprehensive assistance to families: pedagogical, psychological, medical, and will help resolve social and legal issues. For children under one year of age, home visits are provided by specialists. Then you and your child will be able to attend group classes and individual consultations. In the future, associations help adults with Down syndrome adapt to society.

But still, when a child is born with a genetic pathology, the main burden falls on the shoulders of the parents. In order for a child with Down syndrome to become a member of society, you need to make enormous efforts. Constantly during the game you must develop the child’s physical and mental abilities. You can obtain the necessary knowledge from specialized literature.

Early Educational Assistance Program "Little steps", which is recommended by the Russian Ministry of Education. Australian authors Petersi M and Trilor R specifically developed it for children with developmental disabilities. The program describes step-by-step and in detail exercises that relate to all aspects of development.
Montessori system The system of early child development developed by Maria Montessori provides excellent results for the development of children with developmental delays. Thanks to an individual approach, it allows children, in some cases, to even outperform their peers with normal development.

Parents need to be patient. Your baby needs more exercise than other children. He has his own pace. Be calm, persistent and friendly. And one more prerequisite for successful development is to know the baby’s strengths and focus on them in development. This will help the child believe in his success and feel happy.

Strengths of children with Down syndrome

Good visual perception and attention to detail. From the first days, show your child cards with objects and numbers and name them. Thus, learn 2-3 new concepts per day. In the future, learning will also be based on visual aids, signs, and gestures.
They learn to read quite quickly. They can learn the text and use it.
Ability to learn from the example of adults and peers, based on observation;
Artistic talents. Children love to dance, sing, write poetry, and perform on stage. Therefore, art therapy is widely used for development: drawing, wood painting, modeling.
Sports achivments. Athletes with the syndrome show excellent results at the Special Olympics. They are successful in the following sports: swimming, gymnastics, running.
Empathy– understanding the feelings of other people, willingness to provide emotional support. Children perfectly capture the mood and emotions of those around them and subtly sense falsehood.
Good computer skills. Computer skills can become the basis of a future profession.

Features of the physical development of a child with Down syndrome

The first year is the most important period in the life of a child with Down syndrome. If parents only feed and clothe the child, and postpone development and communication until later, then the moment will be missed. In this case, it will be much more difficult to develop speech, emotions and physical abilities.

In the first year of life, the lag is significantly less than in subsequent stages of life. Development is delayed only by 2-5 months. In addition, all functions depend on one another. For example: you taught your child to sit. This leads to other skills - the baby manipulates toys while sitting, which develops motor skills (motor activity) and thinking.

Massage and gymnastics the best way to strengthen muscles and increase their tone. Massage is given to children over 2 weeks old and weighing more than 2 kg. Every month and a half it is necessary to take massage courses. There is no need to constantly contact massage therapists. You can do the massage yourself. In this case, maternal massage is as effective as professional massage.

Massage technique

Movements should be light, stroking. Too much pressure can weaken your baby's already delicate muscles.
Your hand should slide over the baby's body. His skin should not stretch or move.
Pay special attention to your hands and forearms. Here are the reflex zones that are responsible for speech.
Facial massage helps to make facial expressions richer and improve the pronunciation of sounds. Stroke with your fingertips from the back of the nose to the ears, from the chin to the temples. Massage the muscles around your mouth in a circular motion.
The final stage is to lightly touch your forehead and cheeks with your fingertips. If you do this massage 15 minutes before feeding, it will be easier for the baby to suck.

Experts recommend supplementing the massage with active gymnastics using the Peter Lauteslager method or reflexive gymnastics using the Voight method. But dynamic gymnastics and hardening are contraindicated for children with Down syndrome.

Remember that massage and gymnastics speed up blood flow and increase the load on the heart. Therefore, if a child has been diagnosed with a heart defect, it is necessary to first obtain permission from a cardiologist.

First smile, still weak and inexpressive, will appear at 1.5-4 months. To call it, look into the baby's eyes and smile at him. If the child smiles back, praise him and caress him. Such a reward will reinforce the acquired skill.

Revitalization complex. The baby will begin to reach out to you and walk at 6 months. Until this moment, many mothers think that the child does not recognize them or does not love them. This is wrong. It’s just that until the baby is six months old, he cannot express his affection due to muscle weakness. Remember that your child loves you like no one else. He needs the love and care of the whole family much more than his peers.

Ability to sit. It is important that the child learns to sit as early as possible. You will understand that he is ready for this when the baby independently rolls over from back to stomach and back, and also holds his head confidently. There is no need to wait for the child to sit up on his own. Due to anatomical features, it will be difficult for him to do this. After all, his peers’ arms are a little longer and stronger, and they use them to lean on and sit down.

A child with Down syndrome begins to sit by 9-10 months. But each baby has its own pace of development and some children sit down only at 24-28 months. The ability to sit makes it possible to manipulate toys, which is very important for the development of the initial form of thinking. When the child began to sit, it was time to independently hold a cracker or bottle, or take food from a spoon. During this period, you can potty train your baby.

Independent movement. A child begins to crawl at one and a half years old, and to walk at two. In the initial stages, you will have to help your child move his legs so that he understands what is required of him. If he puts his legs too wide, try wearing an elastic bandage around his hips.

A child with Down syndrome can learn almost everything that other children can do: gymnastics, playing ball, riding a bicycle. But this will happen a few months later. Show how to move correctly and what movements to make. Celebrate even the slightest success of your child. Be sure to be generous with your praise.

Personality development in Down syndrome

Low self-regulation. Both children and adults with trisomy 21 find it difficult to regulate their psychophysical processes. It’s hard for them to cope with the emotions that engulf them, fatigue, and force themselves to do something they don’t want to do. This happens because self-regulation is based on influencing oneself using words and images. And people with Down syndrome have problems with this. Following a daily routine will help correct the situation. Practice with your child at the same time every day. This gives the child a sense of security and teaches discipline.

Lack of motivation. It is difficult for such children to imagine the ultimate goal of their actions. It is this image that should encourage activity. Therefore, children are more successful in solving simple one-step problems and get great pleasure from it. Therefore, when working with your child, break the task into simple steps. For example, a child can put one cube on top of another, but he won’t be able to do it if you ask him to immediately build a house.

Autistic disorders found in 20% of children with Down syndrome. They manifest themselves in refusal to communicate and repeated similar actions, a desire for monotony, and attacks of aggression. For example, a child may place toys in a certain order many times in a row, wave his arms aimlessly, or shake his head. A symptom of autism is self-harm, biting. If you notice these signs in your child, contact a psychiatrist.

Cognitive sphere of a child with Down syndrome

Attention to detail. Children pay more attention to small details than to the whole image. It is difficult for them to identify the main feature. Children are good at distinguishing shapes and colors. After several lessons they can sort objects according to a certain criterion.

Watching TV should not take more than 15 minutes a day. Children with Down syndrome love to watch. Changing pictures quickly is harmful to mental health and can cause acquired autism.

Reading It comes quite easily to children. It expands vocabulary and improves thinking. The same applies to writing. Some children prefer to give a written answer rather than answer a question orally.

Short-term auditory memory underdeveloped. It is necessary for people to perceive speech, assimilate and respond to it. Memory capacity is directly proportional to speaking speed. People with the syndrome speak slowly and therefore the volume of this memory is very small. Because of this, it is more difficult for them to master speech, and their vocabulary is poorer. For the same reason, it is difficult for them to follow instructions, understand what they read, and count in their heads. It is possible to train short-term auditory memory. To do this, you need to ask the child to repeat the phrases he heard, gradually increasing the number of words to 5.

Visual and spatial memory in children with Down syndrome are not impaired. Therefore, when training, it is necessary to rely on them. When learning new words, show an object or a card with its image. When you are busy, voice what you are doing: “I’m cutting bread,” “I’m washing my face.”

Problems with math. Insufficient short-term memory, low concentration and inability to analyze material and apply theoretical knowledge when completing tasks become a serious obstacle for children. Oral counting suffers especially. You can help your child by offering to use counting material or count familiar objects: pencils, cubes.

In the learning process, rely on your strengths: imitation and diligence. Show your child a sample. Explain what needs to be done, and he will try to complete the task as efficiently as possible.

Children with the syndrome have their own pace. They experience impulses in the cerebral cortex less frequently than others. Therefore, do not rush your child. Believe in him and give him the necessary time to complete the task.

Speech development

Talk a lot and emotionally. The more you communicate with your child, the better he will speak and the more vocabulary he will have. From the first days, talk to your child very emotionally, but do not baby. Raise and lower your voice, speak softer and louder. This way you develop speech, emotions and hearing.

Mouth massage. Wrap a piece of clean bandage around your finger and gently wipe the roof of your mouth, the front and back of your gums, and your lips. Repeat this procedure 2-3 times a day. This massage stimulates the nerve endings in the mouth, making them more sensitive. In the future, it will be easier for the baby to control his lips and tongue.
Use your thumb and forefinger to close and open your child's lips while playing. Try to do this when he is humming. This way he will be able to pronounce “ba”, “va”.

Name objects and voice your actions.“Now we’ll drink from a bottle! Mom will put on a sweater for you.” Repeated repetition will help the child learn words and associate them with objects.

All activities should be accompanied by positive emotions. Tickle your baby, stroke his arms, pat his legs and tummy. This will stir him up and cause motor activity, which is accompanied by the utterance of sounds. Repeat these sounds after your child. He will be glad that you understand him. This will instill a love of conversation.

Use pictures, symbols and gestures when learning words. For example, you are learning the word car. Show your child a real car and a toy car. Play the sound of the engine and pretend you are turning the steering wheel. The next time you say “car,” remind your child of the whole chain. This will help the child consolidate the term in his memory.

Read to your child. Choose books with bright pictures and developmentally appropriate text. Draw characters from what you read and retell the story together.

Emotional sphere

Emotional sensitivity. Children with Down syndrome are very sensitive to your emotions directed at them. Therefore, after you have decided to keep your child, try to truly love him. In order for the maternal instinct to manifest itself fully, it is necessary to spend more time with the child and breastfeed him.

The most difficult period for parents is the first few weeks after diagnosis. Contact a psychologist at a regional center for assistance to children with special needs. Join a group of parents who are raising children like you. This will help you cope and accept the situation. In the future, the child himself will become your support. After 2 years, children perfectly read the emotions of their interlocutor, pick up on his stress and often make attempts to console him.

Sluggish expression of emotions. During the first few years of life, inexpressive facial expressions do not allow one to look into the baby’s inner world, and problems with speech prevent him from expressing his emotions. Children do not react too actively to what is happening and seem to be half asleep. Because of this, little seems to evoke an emotional response in the child. However, it is not. Their inner world is very subtle, deep and varied.

Sociability. Children with Down syndrome love their parents and the people who care for them. They are very open, friendly and eager to communicate with peers and adults. It is important that your circle of acquaintances is not limited to the rehabilitation center. Playing with peers without the syndrome will help the child develop faster and feel like a member of society.

Increased sensitivity to stress. People with Down syndrome are characterized by increased anxiety and sleep disorders. In boys, these deviations are more common. Try to protect your child from traumatic situations. If this fails, then distract the baby. Invite him to play, give him a relaxing massage.

Tendency to depression. During adolescence, when children realize that they are different from their peers, depression may set in. Moreover, the higher a person’s intellectual development, the stronger it is. People with Down syndrome do not talk about their depression or plans to commit suicide, although they may commit this act. Depression in them manifests itself in a depressed state, delayed reactions, sleep disturbances, loss of appetite, and weight loss. If you notice alarming symptoms, consult a psychiatrist. He will determine the child’s mental state and, if necessary, prescribe antidepressants.

Irritability and hyperactivity. Explosions of emotions are not associated with Down syndrome. Such outbursts are a consequence of concomitant pathologies and stress caused by social isolation, the condition of the parents, or the loss of the person to whom the child was attached. Following a daily routine will help correct the situation. The child should get enough sleep and eat properly. It is advisable to take additional B vitamins, which normalize the functioning of the nervous system.

Benefits of breastfeeding. Children who are breastfed speak better, develop faster and feel happier. But due to weakness of the mouth muscles, they may refuse to suck. To stimulate the sucking reflex, stroke your baby's cheek or the base of his thumb. There are reflex zones here that encourage the baby to continue sucking.

Games

Teach how to use a toy. This also applies to rattles and more complex toys: cubes, pyramids. Place the object in the child’s hand, show how to hold it correctly, what actions can be performed with it.

Required elements: nursery rhyme games, finger games (the well-known Magpie-Crow), nurturing gymnastics. When playing, try to make your child laugh. Laughter is both a breathing exercise, a method of developing will and emotions, and a way to make a child happy.

Natural toys. It is preferable for toys to be made from natural materials: metal, wood, fabric, wool, leather, chestnuts. This helps develop tactile sensitivity. For example, when buying a rattle, wrap a thick woolen thread around its handle. Make a pillowcase from bright fabric for a rustling plastic bag, connect several multi-colored plain silk scarves at the corners. Moving toys are suitable: rotating crib modules, blacksmith toys. Stores sell Montessori toys that are great for educational play.

Musical toys. You should not buy toys with electronic music for your baby. Instead, give him a toy piano, guitar, pipe, xylophone, rattles. With the help of these musical instruments, you can develop your child's sense of rhythm. To do this, play games with musical accompaniment. While listening to fast music, roll the ball together or stomp your feet quickly; while listening to slow music, perform the movements smoothly.

Glove dolls or bi-ba-bo. You put such a toy on your hand and it turns out something similar to a small puppet theater. With the help of bi-ba-bo, you can interest a child, involve him in activities, and calm him down. It has been noticed that in some cases children listen to such dolls better than their parents.

Pathologies that may be detected in a child with Down syndrome

Although these pathologies quite often accompany Down syndrome, it is not at all necessary that they are diagnosed in your child. In any case, modern medicine can cope with these problems.

Prevention of Down syndrome

Contact your doctor promptly for the treatment of various pathologies.
Lead a healthy lifestyle. Active movement improves blood circulation and the eggs are protected from oxygen starvation.
Eat right. Nutrients, vitamins and microelements are necessary to maintain hormonal balance and strengthen the immune system.
Watch your weight. Excessive thinness or obesity disrupts the balance of hormones in the body. Hormonal imbalances can cause disruption in the maturation of germ cells.
Prenatal diagnosis(screening) allows you to timely diagnose serious disorders in the fetus and make a decision on the advisability of terminating the pregnancy.
Plan to conceive in late summer or early fall when the body is stronger and saturated with vitamins. The period from February to April is considered unfavorable for conception.
Taking vitamin-mineral complexes 2-3 months before conception. They should contain folic acid, vitamins B and E. This allows you to normalize the functioning of the genital organs, improve metabolic processes in the germ cells and the functioning of the genetic apparatus.

Down syndrome is a genetic accident, but not a fatal mistake of nature. Your child can live his life happily. It is in your power to help him with this. And even though our country is not yet quite ready to accept such children, the situation is already beginning to change. And there is hope that in the near future people with this syndrome will be able to live in society on an equal basis with everyone else.

Many parents worry about the health of their baby. They are especially concerned that the fetus may develop Down syndrome and other chromosomal pathologies.

Prenatal screening helps identify the likelihood of a baby having various diseases. It is necessary for the purpose of more detailed diagnosis of pathologies using invasive technologies.

Prenatal or antenatal screening does not pose a risk to the health of the mother and fetus, as well as to the course of pregnancy. Invasive techniques can cause a number of complications, which limits their use only when absolutely necessary.

Based on the results of these studies, the doctor identifies the risks of pregnancy, the possibility of having a sick baby, and also decides on the possibility of bearing a child. If any problems arise, the time frame for performing abortion interventions is extended in consultation with the mother.

Description of the pathology

Down syndrome is a chromosomal disorder. Chromosomes are cellular components that carry genetic material. In any cell, except the reproductive ones, there are 46 of them divided into 23 pairs. Of these, 23 are mother’s chromosomes and 23 are father’s, which combine during the fusion of the egg with the sperm.

Gene mutations appear during the first stages of cell division. These changes lead to a decrease or increase in the number of chromosomes, causing a complex of changes in the child’s body with the formation of the disease.

Down syndrome is also synonymous with trisomy 21. A child with this pathology has an additional third chromosome 21, increasing their total number to 47.

Risk factors

The only reliable reason that increases the possibility of having a child with Down syndrome is the age category of the mother. The incidence of a sick baby in a twenty-year-old mother is one case in 1,400 newborns, by the age of 40 it is 1:100, and by the age of 45 it is one case in 35 children.

Among other things, the risk of having a sick baby increases with:

Dad's age is over 45 years.
Presence of patients with genetic abnormalities in the family.
Consanguineous marriages.
The mother is under 18 years of age.

Manifestation of the disease

The first signs of Down syndrome during pregnancy include the occurrence of symptoms of miscarriage or spontaneous abortion.

The life of a child with this pathology is complicated by physical defects in appearance, as well as severe malformations of internal organs.

Main manifestations of Down syndrome:

Flattened face.
Flat bridge of the nose.
Short and wide neck.
The presence of a skin fold that covers the inner corner of the eye.
Thick lips.
Half-open mouth.
Abnormally large tongue.
Chest deformity.
Curvature of the little finger.
Solid “monkey” fold on the palm.

Strabismus.
Hearing loss.
Malformations of the cardiovascular system - ventricular septal defect, atrial septal defect.
Malformations of the gastrointestinal tract - narrowing or absence of the duodenum or esophagus.
Congenital hip dislocation.
Mental retardation.

Prenatal diagnosis

The first screening is carried out at 11–13 weeks of pregnancy.

Diagnosis of the first trimester will include:

Ultrasonography.
Determination of human chorionic gonadotropin levels.
Study of PAPP-A content in the blood.

The second screening is carried out at 15–22 weeks of pregnancy. It consists of:

Ultrasonography.
Determination of alpha-fetoprotein value in maternal blood.
Study of the content of human chorionic gonadotropin and estriol, as well as inhibin A.

For pregnant women who are in a group with an increased risk of having a baby with Down syndrome, it is recommended to undergo invasive diagnostic techniques:

Chorionic villus biopsy.
Amniocentesis.
Cordocentesis with fetal karyotyping.
Consultation with a medical geneticist.

Ultrasonography

Today there are certain markers of Down syndrome in the fetus. Ultrasound signs of the disease are visible changes in the development of the baby.

Main markers of pathology:

Increasing the thickness of the collar space. It is located in the place where the future neck and lower part of the back of the head are formed. An indicator of the likelihood of a fetus having Down syndrome is a thickness of the nuchal translucency exceeding three millimeters.
Absence of nasal bone.
Short tubular femoral and humeral bones.
Signs of the absence of various parts of the intestine.
Anomalies in the structure of the frontal lobe of the brain and cerebellum.

But not one of them is one hundred percent. Only summary ultrasound signs make it possible to conduct a consultation and prescribe invasive research methods.

Laboratory data

This type of examination consists of a blood test for Down syndrome. Determining the content of human chorionic gonadotropin is a reliable diagnostic method. This substance is also called the pregnancy hormone. Refers to indicators of successful pregnancy.

When human chorionic gonadotropin (hCG) levels increase by more than 2 MoM, the doctor prescribes a double or triple test for the woman for a more accurate diagnosis of Down syndrome during pregnancy.

The double test consists of examining the levels of human chorionic gonadotropin and PAPP-A (pregnancy-associated protein) in the first trimester. When the hCG content increases to more than 2 MoM, and the PAPP-A value is less than 0.5 MoM, with up to 90% confidence, they indicate a pathological pregnancy.

This is possible when:

Down syndrome.
Threatened miscarriage.
Frozen pregnancy.

The triple test consists of examining the levels of human chorionic gonadotropin, alpha-fetoprotein and estriol at 15-22 weeks of pregnancy.

Down syndrome is characterized by the following changes in their concentration in the blood of a pregnant woman:

Human chorionic gonadotropin is more than 2 MoM.
Alpha fetoprotein (AFP) is 0.5 MoM.
Free estriol less than 0.5 MoM.
Inhibin A more than 2 MoM.

The triple test is not a mandatory diagnostic measure. But it is recommended to carry it out in the following cases:

Mother's age is more than 35 years.
Presence of people with Down syndrome in the family.
Unfavorable course of previous pregnancies - miscarriages.
Presence of patients with genetic pathologies in the family.
If the mother suffered a serious illness during pregnancy.

If changes in ultrasound examination and laboratory data are combined, the woman is offered invasive methods for diagnosing the genetic material.

Invasive methods

These studies make it possible to accurately determine the development of genetic pathologies in the fetus.

Chorionic villus biopsy is a study in which part of the chorionic villi tissue is obtained from the placenta. This area is identical to the genetic material of the fetus. The procedures are performed under ultrasound control and using anesthesia.

Amniocentesis is the study of amniotic fluid. The material is collected through small punctures in the abdomen. The accuracy of this method reaches 99%.

Cordocentesis is a procedure for collecting cord blood. Diagnosis is carried out under ultrasound guidance. The material is collected through punctures in the abdomen or cervix.

If there are signs of Down syndrome based on ultrasound, laboratory tests and invasive techniques, the attending physician gathers a consultation. After making a decision, the pregnant woman’s medical meeting explains the risk of giving birth to a sick child. In this case, the terms of termination of pregnancy are extended to twenty weeks for medical reasons.

– a chromosomal abnormality in which the karyotype contains additional copies of genetic material on chromosome 21, i.e. trisomy on chromosome 21 is observed. Phenotypic signs of Down syndrome are represented by brachycephaly, flat face and occiput, Mongoloid incision of the palpebral fissures, epicanthus, skin fold on the neck, shortening of the limbs, short fingers, transverse palmar fold, etc. Down syndrome in a child can be detected prenatally (according to ultrasound, chorionic villus biopsy, amniocentesis, cordocentesis) or after birth based on external signs and genetic research. Children with Down syndrome require correction of concomitant developmental disorders.

ICD-10

Q90

General information

Down syndrome is an autosomal syndrome in which the karyotype is represented by 47 chromosomes due to an additional copy of chromosome 21. Down syndrome is registered with a frequency of 1 case per 500-800 newborns. The sex ratio of children with Down syndrome is 1:1. Down syndrome was first described by the English pediatrician L. Down in 1866, but the chromosomal nature and essence of the pathology (trisomy 21) was revealed almost a century later. The clinical symptoms of Down syndrome are varied: from congenital malformations and mental development disorders to secondary immunodeficiency. Children with Down syndrome require additional medical care from various specialists, and therefore they constitute a special category in pediatrics.

Causes of Down syndrome

Normally, the cells of the human body contain 23 pairs of chromosomes (normal female karyotype 46,XX; male - 46,XY). In this case, one of the chromosomes of each pair is inherited from the mother, and the other from the father. The genetic mechanisms for the development of Down syndrome lie in a quantitative disruption of autosomes, when additional genetic material is added to the 21st pair of chromosomes. The presence of trisomy on chromosome 21 determines the features characteristic of Down syndrome.

The appearance of an additional chromosome can be caused by a genetic accident (non-disjunction of paired chromosomes during oogenesis or spermatogenesis), a violation of cell division after fertilization, or the inheritance of a genetic mutation from the mother or father. Taking these mechanisms into account, genetics distinguishes three types of karyotype abnormalities in Down syndrome: regular (simple) trisomy, mosaicism and unbalanced translocation.

Most cases of Down syndrome (about 94%) are associated with simple trisomy (karyotype 47,XX, 21+ or 47,XY, 21+). In this case, three copies of the 21st chromosome are present in all cells due to disruption of the separation of paired chromosomes during meiosis in the maternal or paternal germ cells.

About 1-2% of cases of Down syndrome occur in the mosaic form, which is caused by impaired mitosis in only one cell of the embryo, which is at the blastula or gastrula stage. In mosaicism, trisomy of the 21st chromosome is detected only in derivatives of this cell, and the rest of the cells have a normal chromosome set.

The translocation form of Down syndrome occurs in 4-5% of patients. In this case, the 21st chromosome or its fragment is attached (translocated) to one of the autosomes and, during meiosis, moves along with it into the newly formed cell. The most common “objects” of translocation are chromosomes 14 and 15, less often - on 13, 22, 4 and 5. Such rearrangement of chromosomes can be random or inherited from one of the parents who is a carrier of a balanced translocation and has a normal phenotype. If the carrier of the translocation is the father, then the probability of having a child with Down syndrome is 3%; if the carriage is associated with maternal genetic material, the risk increases to 10-15%.

Risk factors for having children with Down syndrome

The birth of a child with Down syndrome is not related to the lifestyle, ethnicity or region of residence of the parents. The only reliably established factor that increases the risk of having a child with Down syndrome is the age of the mother. So, if in women under 25 years of age the probability of having a sick child is 1:1400, by the age of 35 it is already 1:400, by the age of 40 it is 1:100; and by 45 - 1:35. First of all, this is due to decreased control over the process of cell division and an increased risk of chromosome nondisjunction. However, since the birth rate in young women is generally higher, statistics show that 80% of children with Down syndrome are born to mothers under the age of 35. According to some reports, the father's age over 42-45 years also increases the risk of developing Down syndrome in the child.

It is known that if one of the identical twins has Down syndrome, the other will have this pathology in 100% of cases. Meanwhile, for fraternal twins, as well as brothers and sisters, the likelihood of such a coincidence is negligible. Other risk factors include the presence of persons with Down syndrome in the family, maternal age under 18 years, carriage of the translocation by one of the spouses, consanguineous marriages, random events that disrupt the normal development of germ cells or the embryo.

Thanks to preimplantation diagnostics, conception using ART (including in vitro fertilization) significantly reduces the risk of having a child with Down syndrome in parents at risk, but does not completely exclude this possibility.

Down syndrome symptoms

Carrying a fetus with Down syndrome is associated with an increased risk of miscarriage: spontaneous abortion occurs in approximately 30% of women at 6-8 weeks. In other cases, children with Down syndrome, as a rule, are born full-term, but have moderately severe hypoplasia (body weight is 8-10% below average). Despite the various cytogenetic variants of the chromosomal abnormality, most children with Down syndrome have typical external signs that suggest the presence of pathology already at the first examination of the newborn by a neonatologist. Children with Down syndrome may exhibit some or all of the physical characteristics described below.

80-90% of children with Down syndrome have craniofacial dysmorphia: flattened face and bridge of the nose, brachycephaly, short wide neck, flat back of the head, deformation of the ears; newborns - a characteristic skin fold on the neck. The face is distinguished by a Mongoloid shape of the eyes, the presence of an epicanthus (a vertical fold of skin covering the inner corner of the eye), microgenia, a half-open mouth often with thick lips and a large protruding tongue (macroglossia). Muscle tone in children with Down syndrome is usually low; there is hypermobility of the joints (including atlanto-axial instability), deformation of the chest (keeled or funnel-shaped).

Characteristic physical signs of Down syndrome are meek limbs, brachydactyly (brachymesophalangy), curvature of the little finger (clinodactyly), a transverse (“monkey”) fold in the palm, a wide distance between the 1st and 2nd toes (sandal cleft), etc. When examining children with the syndrome Down's reveals white spots along the edge of the iris (Brushfield spots), gothic (arched palate), malocclusion, and grooved tongue.

With the translocation variant of Down syndrome, external signs appear more clearly than with simple trisomy. The severity of the phenotype in mosaicism is determined by the proportion of trisomic cells in the karyotype.

Children with Down syndrome are more likely than others in the population to have congenital heart disease (patent ductus arteriosus, VSD, ASD, tetralogy of Fallot, etc.), strabismus, cataracts, glaucoma, hearing loss, epilepsy, leukemia, gastrointestinal defects (esophageal atresia, stenosis and duodenal atresia, Hirschsprung's disease), congenital hip dislocation. Typical dermatological problems of puberty are dry skin, eczema, acne, and folliculitis.

Children with Down syndrome are often ill; they suffer more severely from childhood infections and more often suffer from pneumonia, otitis media, ARVI, adenoids, and tonsillitis. Weak immunity and congenital defects are the most likely cause of death in children in the first 5 years of life.

Most patients with Down syndrome have intellectual development disorders - usually mild or moderate mental retardation. The motor development of children with Down syndrome lags behind their peers; There is a systemic underdevelopment of speech.

Patients with Down syndrome are prone to developing obesity, constipation, hypothyroidism, alopecia areata, testicular cancer, early-onset Alzheimer's disease, etc. Men with Down syndrome are typically infertile; Women's fertility is markedly reduced due to anovulatory cycles. The height of adult patients is usually 20 cm below average. Life expectancy is about 50-60 years.

Diagnosis of Down syndrome

For prenatal detection of Down syndrome in the fetus, a prenatal diagnostic system has been proposed. First trimester screening is carried out at 11-13 weeks of pregnancy and includes identifying specific ultrasound signs of anomaly and determining the level of biochemical markers (hCG, PAPP-A) in the pregnant woman’s blood. Between 15 and 22 weeks of pregnancy, second trimester screening is performed: obstetric ultrasound, maternal blood test for alpha-fetoprotein, hCG and estriol. Taking into account the woman’s age, the risk of having a child with Down syndrome is calculated (accuracy - 56-70%; false positive results - 5%).

Pregnant women at risk of having a child with Down syndrome are offered prenatal invasive diagnostics: chorionic villus biopsy, amniocentesis or cordocentesis with fetal karyotyping and consultation with a medical geneticist. Upon receipt of information that the child has Down syndrome, the decision on whether to prolong or terminate the pregnancy remains with the parents.

Newborns with Down syndrome in the first days of life need an echocardiogram, a cardiologist, a speech therapist and an oligophrenopedagogist.

Children with Down syndrome are usually educated in a special correctional school, but within the framework of integrated education, such children can also attend a regular public school. In all cases, children with Down syndrome are classified as children with special educational needs, and therefore require additional help from teachers and social educators, the use of special educational programs, and the creation of a favorable and safe environment. Psychological and pedagogical support for families raising “sunny children” plays an important role.

Forecast and prevention of Down syndrome

The learning and socialization capabilities of persons with Down syndrome are different; they largely depend on the intellectual abilities of children and on the efforts made by parents and teachers. In most cases, children with Down syndrome manage to acquire the minimum household and communication skills necessary in everyday life. At the same time, there are known cases of success of such patients in the field of fine arts, acting, sports, as well as higher education. Adults with Down syndrome can lead an independent life, master simple professions, and start families.

Prevention of Down syndrome can only be discussed from the perspective of reducing possible risks, since the likelihood of having a sick child exists in any couple. Obstetricians and gynecologists advise women not to delay pregnancy until later in life. Genetic counseling of families and a prenatal screening system are intended to help predict the birth of a child with Down syndrome.

From a medical point of view, Down syndrome during pregnancy is the presence of one extra chromosome in the fetus. And from the point of view of life, this is a serious burden and responsibility that falls on the shoulders of parents, since caring for and raising a special child requires considerable moral and material strength.

All children suffering from Down syndrome differ from healthy people in the intellectual and physical sense; it is extremely difficult for them to adapt to independent life in society.

Therefore, raising such a child is difficult in every way. To avoid this, experts suggest that all women undergo screening diagnostics aimed at identifying existing pathologies in the fetus, including signs of Down syndrome during pregnancy.

Down syndrome is a pathology that occurs against the background of a violation of the set of chromosomes that the unborn child receives from both parents. Children with this diagnosis are born not with 46, but with 47 chromosomes.

Down syndrome, from the point of view of geneticists, cannot be called a disease, since a person born with this pathology has a certain set of signs and traits characteristic of such people.

Deviation Features:

Down syndrome cannot be called a rare phenomenon, since for every 700 births there is 1 case of a child being born with this pathology. By the way, these days this statistics has changed significantly, the ratio has become 1100: 1, as the number of induced abortions and births among women who learned about the deviation of their child through a test for Down syndrome during pregnancy has increased.
The percentage of female and male infants with a similar chromosome disorder is the same.
The pathology does not depend on ethnicity and nationality, as well as on the standard of living of parents.

In women under 24 years of age, the probability of having a child with Down syndrome is 562: 1. From 25 to 30 years old - 1000: 1, from 30 to 39 - 214: 1. Expectant mothers whose age has exceeded 45 years are at maximum risk, statistics in this case inexorable - 19: 1. If the child’s father is over 42 years old, the likelihood of having a child with Down syndrome is several times higher.

80% of children with this disorder are born to women under 35 years of age, which is explained by the high birth rate in this age group.

Children born with this pathology are usually called “sunny” children, as they are distinguished by excessive warmth and kindness, and a constant happy smile on their face. Such children do not know how to get angry and envy, but they find it difficult to adapt to life due to physical and mental disabilities. For what reasons are such children born?

Causes

Experts still cannot give an exact list of the reasons that resulted from the birth of a child with Down syndrome. To date, very few decisive factors have been identified in this problem.

Let's list them:

mother's age over 35 years;
father's age is over 42 years;
a random unfavorable combination of circumstances that arose at the moment of fertilization and division of the first cells;
deficiency in the body of the expectant mother (an assumption not confirmed by science).

At the same time, geneticists are confident that the appearance of chromosomal abnormalities is not influenced by negative environmental factors and the lifestyle of both parents. For this reason, spouses should not blame themselves if a fetus or newborn is diagnosed with a pathology.

Diagnostics

In the first trimester, Down syndrome during pregnancy is determined using. But the likelihood of error will be increased compared to laboratory tests that are carried out in the second trimester.

If the ultrasound results are positive, for example, gross developmental pathologies similar to signs of a chromosomal disorder are detected in the fetus, the woman is asked to undergo additional, more accurate research methods.

Additional studies are carried out if the analysis for Downism during pregnancy shows a questionable or positive result.

These include:

amniocentesis - for research, amniotic fluid is taken, with the help of which the chromosome set of the unborn child can be determined in a laboratory;
chorionic villus test - a piece of tissue is taken for diagnosis;
cordocentesis - umbilical cord blood is taken through the skin barrier.

It is worth noting that not all women agree to be tested for Down syndrome during pregnancy, worrying about the possibility of spontaneous miscarriage during the manipulation. It turns out that they are ready to become the mother of an unhealthy child rather than be left without him.

How long does screening diagnostics take?

To determine the signs of Down syndrome during pregnancy, screening diagnostics are carried out at the following times:

Chorionic villus biopsy - 10-12 weeks. The result will be obtained in a few days, the procedure is dangerous with the risk of spontaneous abortion - in 3% of cases.
Placentocentosis - 13-18 weeks. The result is a few days later, the risk of miscarriage is the same.
Amniocentesis - 17-22 weeks. Risk of miscarriage 0.5%.
Cordocentesis - 21-23 weeks. Risk of miscarriage 2%.

With a high degree of probability, it is possible to judge the presence of this pathology in an unborn child based on the results of an ultrasound scan if gross anatomical abnormalities are detected.

These include the following signs of Down syndrome during pregnancy::

Enlarged nuchal space, which may occur due to a large thickness of the neck fold or accumulation of fluid on the back of the fetal neck. Normally, this figure should not be more than 2.5 mm with transvaginal ultrasound and 3 mm when performing the procedure through the abdominal wall. Ultrasound during pregnancy for Down syndrome is not carried out specifically, since during the manipulation the general condition of the fetus is assessed and other anomalies of its development are diagnosed, therefore all women undergo it as planned from 10 to 13 weeks.
The length of the nasal bones of the unborn child is assessed in the second trimester. Every second child with Down syndrome has hypoplasia of the nasal bones. Also, during an ultrasound, an enlargement of the bladder, a decrease in the maxillary bone, tachycardia more than 170 beats per minute, and changes in blood flow in the venous duct can be detected.

If a Down ultrasound during pregnancy reveals one or more signs of abnormality, this does not mean that the result is 100% reliable. In this case, the woman will be referred to the tests listed above, the results of which will be as accurate as possible. An ultrasound examination at the end of the first trimester most accurately determines the risk of pathology and helps to take appropriate measures.

There is also a venous blood test for Down during pregnancy, which consists of determining the concentration of the hormone and alpha-fetoprotein. Alphafetoprotein is a protein compound synthesized by fetal liver cells. A low concentration of this protein indicates the presence of Down syndrome, just like hCG. Diagnosis is carried out at 16-18 weeks.

Is it worth doing?

Screening is strongly recommended for a woman if she is over 35 years old, if the father of the child is a close relative, or if she has previously given birth to children with chromosomal abnormalities. The doctor may also refer a woman for screening who has recently received radiation, x-rays, or other radiation.

In addition, diagnosis is mandatory for expectant mothers who become pregnant against the background of a viral or bacterial pathology, have a history of pregnancy, or have taken illicit medications during conception.

If one of the diagnostic procedures indicates signs of Down syndrome during pregnancy, the woman has the right to terminate it at her own request until the 22nd week.

Of course, the possibility of spontaneous abortion during research may be an unpleasant price to pay for the correct result, especially if the child does not have this diagnosis and turns out to be healthy. Therefore, not all women agree to undergo testing for Down signs during pregnancy.

Even if, due to moral or religious beliefs, the expectant mother knows for sure that she will not terminate the pregnancy if a deviation in the baby is confirmed, in any case, everyone without exception needs to undergo diagnostics. At least in order to find out the truth about the health of your child in time and mentally prepare yourself and your loved ones for his birth, if he turns out to be special.

Prognosis for a confirmed diagnosis

According to long-term observations, children with this diagnosis develop differently. The severity of their intellectual and speech developmental delay does not depend on the existing congenital pathology, but on the individual contribution to a particular child. That is, children with Down syndrome can learn, it’s just that this process is harder for them than for their healthy peers, hence the lag.

Experts believe that with appropriate care and treatment, the prognosis will be as follows:

with a certain delay, but the child will learn to speak, walk, master the basics of literacy, that is, he will be able to do what many can;
there will definitely be speech problems;
training can take place both in a specialized and in a general education school;
marriage unions are possible;
half of women with Down syndrome can achieve the happiness of motherhood, but half of these children will be born unhealthy;
Currently, the average life expectancy of such people is 50 years;
their likelihood of cancer is reduced to a minimum.

It is difficult to predict what a child born with Down syndrome will be like. Everything is very individual. Future parents who decide to leave the pregnancy can be guided by the above-listed forecasts for this gene deviation.

Is it possible to prevent the occurrence of this pathology in an unborn child? Unfortunately, there are no preventive measures to prevent this deviation.

But doctors advise not to ignore the following recommendations::

undergo consultation with a geneticist before and after conception;
give birth to children before 40 years of age;
Take multivitamins, including folic acid, during and during the first trimester.

It is important to understand that no one is to blame for the conception and birth of a special child. This is just an accident of nature, a chromosomal error. Because of her, extraordinary children come into our lives - bright, kind, trusting. Whether or not to accept such a baby into their family is up to each family to decide individually.

Useful video about diagnosing Down syndrome during pregnancy

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How long does it take for Down syndrome to be detected? Late application analysis

How is Down syndrome diagnosed during pregnancy?

What parents of children with Down syndrome need to know.

Causes of Down syndrome

Signs and symptoms of Down syndrome during pregnancy

Screening for genetic abnormalities during pregnancy

Ultrasound

Blood chemistry

Amniocentesis

Cordocentesis

Chorionic villus biopsy

Signs and symptoms of Down syndrome in a newborn

Signs and symptoms of Down syndrome in children and adults

How does a child with Down syndrome develop?

Strengths of children with Down syndrome

Features of the physical development of a child with Down syndrome

Personality development in Down syndrome

Cognitive sphere of a child with Down syndrome

Speech development

Emotional sphere

Games

Pathologies that may be detected in a child with Down syndrome

Prevention of Down syndrome

Description of the pathology

Risk factors

Manifestation of the disease

Prenatal diagnosis

Ultrasonography

Laboratory data

Invasive methods

ICD-10

General information

Causes of Down syndrome

Risk factors for having children with Down syndrome

Down syndrome symptoms

Diagnosis of Down syndrome

Forecast and prevention of Down syndrome

Causes

Diagnostics

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Is it worth doing?

Prognosis for a confirmed diagnosis

Useful video about diagnosing Down syndrome during pregnancy

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