Developmental defects incompatible with life. Congenital anomalies of fetal development

Sadly, according to medical statistics, about 5% of healthy parents are at risk of giving birth to children with mental or physical developmental disorders. Is it possible to find out about fetal pathologies in advance? Is the diagnosis of “fetal pathology” always a death sentence for an unborn baby?

At what stages of pregnancy can you find out about fetal pathology?

Blood screening tests are carried out:

• at 11-13 weeks - “Double test”. It analyzes 2 protein blood indicators, which can be used to judge the child’s risk of developing chromosomal disorders such as Down syndrome and Edwards syndrome.
• at 14-15 weeks - “Triple test”. In addition to the above-mentioned syndromes, it can predict the presence of neural tube defects.

When calculating the risk of pathologies, the following MUST be taken into account: multiple pregnancy, IVF, woman’s weight, diabetes mellitus, the presence of colds at the time of the test, smoking. All of these factors can greatly inflate risk estimates.

Screening studies only determine the PROBABILITY of the occurrence of chromosomal abnormalities! If the indicators are positive, additional examination is necessary: ​​ultrasound, chorionic villus biopsy, amyocentesis, cordocentesis.

Ultrasound at 11-14 weeks of pregnancy can reveal obvious developmental pathologies and some changes indicating chromosomal abnormalities of the fetus.

Ultrasound at 20-22 weeks diagnoses malformations of internal organs.

Attention! If the ultrasound showed the presence of abnormalities, it is necessary to double-check the diagnosis with 2-3 doctors to avoid mistakes!

Chorionic villus biopsy- analysis of placenta cells. It is carried out at 8-12 weeks. Amniocentesis is a cytogenetic analysis of amniotic fluid. It is carried out at 16-24 weeks. The safest of invasive research methods. The risk of complications after it does not exceed 1%. Cordocentesis is puncture of the fetal umbilical cord. Carried out at 22-25 weeks.

If a child has a pathology

Doctors recommend abortion or inducing premature birth only if the fetal pathology is incompatible with life. Most pathologies do not require termination of pregnancy. The level of modern medicine makes it possible to “correct” many developmental defects after the baby is born.

If you find out that a child has a pathology compatible with life, try to collect as much information as possible about the nature of the disorders and which medical institutions can help you. For example, it is now possible to surgically eliminate even complex congenital heart defects within a few days after the birth of a child. After surgery, babies grow and develop in the same way as their healthy peers. Some physical disorders may go away on their own as the child grows, while others require treatment or surgery. So there is always hope!

Ultrasound diagnostics is performed on pregnant women three times. But if the need arises, the doctor may prescribe additional research to confirm or exclude the diagnosis.

At each of the planned ultrasounds, the doctor looks at what the fetus looks like. Do the head, legs, arms, belly, nose correspond to the stage of development at which the baby is. At a later stage, the doctor identifies which organs are developed correctly: heart, stomach, liver, etc.

Ultrasound up to 12 weeks

Ultrasound of early pregnancy

Sometimes ultrasounds are done up to 12 weeks. This is shown in the following cases:

• Complicated obstetric and gynecological history. That is, if in the past there were cases of miscarriages, miscarriage, suspicion of a “frozen” pregnancy, etc.
• Complications during the current pregnancy (bleeding, acute abdominal pain)
• Pregnancy that occurred after IVF
• If during a previous pregnancy fetal pathologies were identified (Down syndrome or other trisomies, hydrocephalus, etc.)

Also, up to 12 weeks, ultrasound can be performed on women with suspected hematoma. A hematoma occurs when the pregnant uterus is exposed to harmful factors (infections, gestosis). Hematoma happens:

• Retrochorionic.
• Retroplacental.

These hematomas differ only in the moment of their formation. If the hematoma has formed without a formed placenta, then it is called retrochorial.

In the early stages of pregnancy, a small hematoma, as a rule, does not cause abdominal pain and is detected by ultrasound. But it happens that in the early stages there is a large hematoma, this is dangerous for termination of pregnancy. In the later stages, the hematoma negatively affects the fetus - it leads to hypoxia and a decrease in fetal size. Early detection and small size of the hematoma will help to heal and give birth to a healthy full-term baby. Treatment of hematoma generally requires hospitalization.

What can be detected in the first trimester?

During the first ultrasound, you can determine the risk of developing Down syndrome and some other chromosomal pathologies. The most important thing is that the fruit is of a certain size. The CTP (coccygeal-parietal size) is measured; it should be no less than 45 mm, but no more than 84 mm. If the fetus is too small or, on the contrary, large, then it will be impossible to interpret such an indicator as the thickness of the collar space or zone (TVP).

First trimester screening can detect some chromosomal diseases of the fetus

The thickness of the collar zone is the thickness of all tissues in the neck area. Normally, this figure does not exceed 2.7 mm, and the average value is 1.6 mm. If the size of the collar zone is more than 3 mm, then the likelihood of Down syndrome in the fetus is very high. Of course, one indicator does not give the right to make such a serious diagnosis. A pregnant woman is advised to undergo a number of examinations, including a biochemical blood test and amniocentesis. The age of the pregnant woman is important in confirming the presence of Down syndrome in the fetus. If a woman is over 35 years old, the risk of having a child with Down syndrome increases markedly.

If Down syndrome is suspected in the fetus, additional measurements of brain structures are performed (if the thickness of the collar zone is normal, then these measurements may not be performed). The cerebellum in Down syndrome is reduced in size, as is the frontal lobe. Also, with this syndrome, ultrasound reveals a shortening of the frontothalamic distance.

The nose in Down syndrome is flattened and shortened, and the bone above the nose has a saddle shape. This is due to the development of the nasal bones. With this pathology, the nose ossifies with some delay, and therefore, at the first ultrasound, the sonologist may simply not see the nose. Of course, with further development, the nose appears, but it decreases in size and is somewhat deformed.

Fetometry at 12 weeks includes measuring the size of individual organs and body parts. The size of the head (biparietal size) is 21 mm, the length of the thigh is approximately 8 mm. In addition, the abdominal and head circumference and shoulder length are assessed.

Suspicion of defects found on ultrasound at 12 weeks is not in all cases confirmed by further examination. But if at this stage there were suspicions of the presence of Down syndrome, then during subsequent ultrasounds the doctor will study the parameters of the fetus in more detail and closely.

Second scheduled ultrasound

Second trimester screening

It is carried out at 20-22 weeks of pregnancy. By this time, the child’s structures are developed and visible much better. It is already possible to evaluate the structure of individual organs and identify their pathology. By this time, the fetal heart is fully formed, as are the kidneys and pelvis. The presence of heart defects with simultaneous dilation of the renal pelvis should suggest the presence of Down syndrome. During this period, an experienced doctor will notice changes in the nose characteristic of Down's disease. The nose is widened along with the bridge of the nose.

Gastrointestinal tract on ultrasound

The baby's stomach is also more formed by this time and must have a cavity. Sometimes it happens that the cavity is not visualized or, on the contrary, its expansion is observed. Sometimes this can only be an accident - the fetus has taken a certain position, a bad ultrasound sensor, and sometimes the absence or expansion of a cavity in the stomach can indicate serious pathologies of the fetus.

First, the specialist needs to make sure that the stomach is there. Because Sometimes it is possible to develop a defect such as a diaphragmatic hernia, in which the stomach moves from the abdominal cavity to the chest cavity. If the stomach is in the right place, then you need to trace its connection with the esophagus and intestines.

With esophageal atresia, the gastric cavity is not identified. If a problem occurs in the pyloric region (the section of the stomach in front of the small intestine), then the cavity may contain hyperechoic inclusions and may even be dilated. Various types of inclusions in the fetal stomach should be differentiated from a tumor. Sometimes the fetus can ingest blood in utero, which will also be noticeable on an ultrasound. But such situations rarely lead to an increase in the stomach cavity; it still remains relatively small.

It is worth noting that the normal size of the stomach is quite variable. As a result, it is difficult to determine the expansion of the cavity or the enlargement of the entire stomach. It is necessary to evaluate the abdominal circumference and correlate it with other parameters.

The small intestine in the second trimester of the fetus is also well formed. It should be approximately the same diameter and not contain hyperechoic inclusions. If an ultrasound reveals high-density inclusions, this may be a sign of certain pathologies that will later be confirmed in the newborn. Meconium ileus syndrome (hyperechoic inclusions in the intestine) can be a sign of genetic pathology (cystic fibrosis, Down syndrome, trisomy 18 and 13).

Brain research

Ultrasound examination of the fetal brain

During the second screening ultrasound, it is possible to evaluate the structures of the brain in more detail. By 22 weeks, the ventricles of the brain are well formed. An increase in their size is called ventriculomegaly. Many specialists initially call this hydrocephalus. But the concept of hydrocephalus also includes increased intracranial pressure and increased head size. Normally, when measuring the lateral ventricles transversely, the size should be up to 10 mm. But in different sources the sizes vary somewhat.

Hydrocephalus can be suspected if genetic pathologies (for example, Down syndrome) are detected in the fetus. There is also a high probability of hydrocephalus in the fetus if the mother suffered some infections during pregnancy. For example, toxoplasmosis, herpes virus, rubella cause multiple pathologies of the fetus, including hydrocephalus

If a specialist diagnosed ventriculomegaly at the second planned ultrasound, then at 30 weeks we can talk about hydrocephalus.

Also, during the second ultrasound, the doctor can look at the fetus’s face. At this stage, it is fully formed - the nose and lips resemble those of newborns. If there is a cleft between the nose and lip, the doctor will also examine it. Clefts can be on one side of the nose or both. Sometimes this defect is combined with a cleft palate. Other nasal pathologies are not visible on ultrasound at this time.

Ultrasound at 30 weeks

At the third planned ultrasound, it is possible to confirm or exclude previously made diagnoses. For example, you can trace the entire gastrointestinal tract to the rectum. Sometimes, the contents of the colon contain hyperechoic inclusions - this is a normal variant. The lumen of the small intestine is small in relation to the large intestine.

The head should not be larger than normal, otherwise it will be evidence of hydrocephalus. Of course, head size alone is not enough to diagnose hydrocephalus; the ventricles must also be enlarged. And if external hydrocephalus has developed, then the subarachnoid space increases.

Diagnosis of hypoxia

In a normal pregnancy, an ultrasound at 30 weeks is the last one before birth. A third ultrasound is often performed using Doppler. This is necessary to assess blood flow in the placenta and identify hypoxia.

In addition to Dopplerometry, the general picture on ultrasound will help in identifying hypoxia - the fetus is small and actively moving. CTG analysis is also important for diagnosing hypoxia. With oxygen starvation, the child’s heart beats too slowly (up to 130 beats when moving, up to 110 at rest).

With hypoxia, the child tries to find a place for himself and moves too intensely, which can lead to entanglement in the umbilical cord.

Why is entanglement in the umbilical cord dangerous?

Quite often, during this ultrasound, the doctor detects the umbilical cord entwined around the head, or rather the neck, of the fetus. In some cases, by the time of birth, the baby moves and turns several more times in utero and “unravels.” If there is no clamping of the umbilical cord and there are no knots on it, then the entanglement itself does not cause discomfort to the fetus, it develops and grows well. And if there were no problems during childbirth (the doctor freed the head from the umbilical cord in time), then entanglement is also not a cause for concern.

Umbilical cord entanglement

You should only worry if there is a tight entanglement in the umbilical cord. In this case, the blood flow between mother and child is disrupted. Tight umbilical cord entanglement can be isolated, or it can be combined with another entanglement (one around the neck, the second around the head, abdomen or other part of the body). At the same time, the umbilical cord itself shortens and limits the mobility of the fetus.

There are cases of repeated entanglement of the umbilical cord around the baby's neck. This option is not very favorable, but if it does not cause hypoxia, it can result in the birth of a healthy baby.

The most unfavorable outcome when the umbilical cord is entangled and the resulting hypoxia is cerebral palsy and other neurological disorders of the newborn.

Causes of cerebral palsy

• Hypoxia before or during childbirth.
• The weight of a premature baby is less than 2000 g.
• Intrauterine infections and other teratogens (drugs).

Married couple planning pregnancy

The development of cerebral palsy can only be prevented through preventative measures - planning pregnancy, avoiding taking harmful medications, and avoiding stressful situations. New scientific research is increasingly revealing a genetic predisposition to cerebral palsy.

It should be noted that a diagnosis such as cerebral palsy is made only after 1 year. Until then, the baby lives with neonatal encephalopathy. Cerebral palsy is diagnosed after a year, because This diagnosis requires some clinical manifestations that need to be monitored during the first 12 months of life.

To confirm cerebral palsy, a number of examinations are carried out: EEG, CT scan of the head, etc. The child’s parents should closely monitor the development of the baby in order to see signs of the development of cerebral palsy or its absence. It is not known for certain how long after birth it will take for the clinic to develop.

Most fetal pathologies are diagnosed by ultrasound. That is why ultrasound diagnostics is included in screening.

The birth of a child with congenital developmental defects is always stunning for the family; this topic is one of the most difficult in obstetrics. At the first moment, the spouses experience an incomparable psychological shock, which then turns into a feeling of guilt; it seems to them that they will never have a healthy child.

It should be said right away that a child with congenital defects can be born into absolutely any family - young, healthy, without bad habits, with a normal pregnancy. According to long-term statistics, around the world, about 5% of children are born with congenital diseases.

Congenital malformations of the fetus can be divided into two large groups - hereditary (that is, embedded in genes and chromosomes, transmitted by inheritance) and actually congenital (acquired during intrauterine development). This division is quite arbitrary, since most developmental defects are caused by a combination of hereditary predisposition and adverse external influences, representing multifactorial anomalies.

The problem of congenital malformations of the fetus is very diverse; various specialists study this issue - geneticists, neonatologists, embryologists, and specialists in prenatal (prenatal) diagnostics. Understanding the reasons is always difficult.

Hereditary diseases

Mutations are the basis of hereditary diseases. Thanks to modern blood-curdling thrillers, this word now evokes almost superstitious horror in many. In fact, the Latin word mutatio means “change” - nothing more. A mutation is a change in the hereditary properties of an organism as a result of rearrangements in the structures responsible for the storage and transmission of genetic information. Diseases associated with pathological changes in chromosomes are usually called chromosomal diseases. Under actual hereditary diseases understand disorders caused by gene mutations.

Table 1 below lists, by way of example, just some of the life-threatening hereditary anomalies.

Anomaly	Inheritance mechanism	Manifestation	Treatment and rehabilitation measures
Phenylketonuria (PKU)	Autosomal recessive inheritance - the birth of a sick child from healthy parents is possible. The frequency in the population is 1:2000.	Severe delay in mental and physical development associated with impaired metabolism of the amino acid phenylalanine.	Examination of ALL newborns for PKU on the 4th-5th day of life. A special diet can prevent the development of the disease.
Hemophilia	Sex-linked recessive inheritance. Mostly men are affected. Passed on from mother to sons.	The disease is caused by a deficiency of certain blood clotting factors. It appears as bleeding.	Treatment for bleeding - blood transfusion, plasma; general hemostatic agents; antihemophilic globulin; prevention of injuries and bleeding.
Colorblindness	Sex-linked recessive inheritance. It is observed mainly in men. Passed on from mother to sons.	Partial color blindness. It is most often distributed in red and green colors.	Color vision disorders are detected using special tables or spectral devices. Color blindness cannot be treated.
Down's disease	Chromosomal abnormality: in the mother, during the maturation of the egg, under the influence of as yet unclear reasons, 3 chromosomes are formed in the 21st pair of chromosomes instead of 2. The frequency in the population is 1:700.	One of the forms of congenital dementia. The degree of mental underdevelopment varies significantly. Patients are generally affectionate, good-natured, and friendly.	Therapeutic pedagogy based on the tendency of patients to imitate. Education in auxiliary schools, occupational therapy.
	Autosomal dominant inheritance is transmitted to children from parents with a congenital form of the disease.	Drooping of the upper eyelid due to underdevelopment of the muscle that lifts it.	Surgery.

Congenital multifactorial malformations

Congenital malformations are very diverse; they can affect almost any organ of the fetus. Their occurrence is caused by various adverse effects on the fetal organs, especially in the early stages of pregnancy. Factors that cause fetal malformations are called teratogenic. The most studied types of teratogenic effects are the following:

• Ionizing radiation (X-rays, exposure to radioactive isotopes). In addition to the direct effect on the genetic apparatus, ionizing radiation has a toxic effect and is the cause of many congenital anomalies.
• Teratogenic infections , i.e. infectious diseases transmitted from mother to fetus.
• Medicines . There are no medications that can be unconditionally recognized as completely safe, especially in the early stages of pregnancy. During pregnancy, medications should be taken only as prescribed by the attending physician and taking into account their possible effect on the fetus. (See S. Gonchar “Medicines and Pregnancy” in this issue of the magazine. - Approx. ed.) You should not go to the other extreme and not treat follicular tonsillitis or a carious tooth just because “the pills are harmful for a pregnant woman.” It’s good for the fetus if the mother feels good!
• Alcohol . Drinking alcohol in large doses by a pregnant woman can lead to the development of fetal (i.e., affecting the fetus) alcohol syndrome - a severe congenital disease, sometimes incompatible with life. But you shouldn’t exaggerate the risk - a glass of champagne drunk before conception is not at all a reason to terminate a pregnancy! If you are concerned about the risk of “drunk conception,” be sure to consult a geneticist.
• Nicotine . Smoking a large number of cigarettes during pregnancy leads to retarded physical development of the child.
• Exposure to toxic chemicals . Women who have contact with active chemicals due to their work should plan pregnancy. 2-3 months before conception and the entire period of pregnancy (especially up to 14-16 weeks), it is advisable to avoid contact with chemicals that can cause a teratogenic effect in the fetus.

Often, however, a factor such as hereditary predisposition plays a role in the development of congenital defects: it is known that if parents or close relatives had congenital malformations, then the risk of giving birth to a child with similar defects increases, that is we're talking about“about the family accumulation” of developmental anomalies. Thus, a woman with a congenital heart defect has a slightly higher chance of giving birth to a child with a defect in the development of the cardiovascular system than all other women. Therefore, it is customary to talk not so much about simply congenital, but about congenital multifactorial malformations . However, a large amount of statistical material shows that the repeated risk of having a child with a congenital malformation is small - on average 2-4%. Let us give several examples of congenital multifactorial malformations compatible with life (see. Table 2).

I would like to emphasize once again that when it comes to congenital malformations, the question “who is to blame?” often remains unanswered, it is more productive to look for an answer to the question “what to do?” Let's talk about this topic.

Developmental defect	Manifestations	Treatment
	The emergence of internal organs or deep tissues from the cavities usually occupied by them, under the skin or into the intermuscular tissue without violating the integrity of the integument.	Massage, if it is ineffective - surgical treatment.
Congenital dislocation and congenital dysplasia of the hip joint	Congenital dysplasia of the hip joint is underdevelopment of the tissues of the hip joint, lack of correspondence between the articular surfaces - a condition that precedes dislocation of the hip joint.	For dysplasia, use of various orthoses (devices for hip abduction) in children under one year of age. In case of dislocation - reduction, application of special orthoses in the first months of life. If such treatment fails, surgery is required.
Cleft lip (cleft lip)	Failure of fusion of the lateral parts of the upper lip with its middle part. Can be one-sided or two-sided. Makes sucking difficult.	Surgery in the first months of life.
Cleft palate (cleft palate)	Non-fusion of the upper jaw and hard palate, resulting in a cleft connecting the oral and nasal cavities. Causes disturbances in nutrition (food entering the windpipe, nasal cavity), breathing and speech. Often combined with a cleft in the upper lip.	Surgery and prosthetics; dispensary observation (change of medical devices) up to 16 years.
Polydactyly	Polydactyly - polydactyly, the presence of extra fingers on the hand or foot. The most common congenital malformation; most often found in a six-fingered form, usually on one limb.	Surgery.
Congenital heart defect	Incorrect intrauterine formation of the heart septum (for example, non-closure of the interatrial or interventricular septum) or the persistence of intrauterine circulation after birth (for example, patent ductus botallus) .	With minor defects of the interventricular septum, as the heart grows, the relative size of the opening decreases - until complete spontaneous closure. In other cases - surgical treatment.

What to do, if…

1. You are planning a pregnancy

It is known that the “risk group” from the point of view of the birth of offspring with congenital diseases includes:

• men and women in whose families one or another hereditary disease has already occurred, even if they themselves are not sick;
• families where there are already children suffering from congenital malformations;
• families in which previous pregnancies ended in miscarriages or stillbirths;
• spouses who are related (for example, first and second cousins);
• women over 35 and men over 50;
• men and women who, due to their occupation, health status or for some other reason, are exposed to the teratogenic factors listed above.

In all these cases, we strongly recommend that partners planning pregnancy attend a medical genetic consultation. Geneticists will draw up a pedigree and determine the risk of having a child with a hereditary disease. The current level of development of medical technologies allows today, in case of an unfavorable prognosis, to resort to artificial insemination with donor sperm or fertilization of a donor egg. In addition, exposure to teratogenic factors should be eliminated or minimized whenever possible.

2. You are expecting a baby

and are part of one of the listed “risk groups”. The first step in this case should be a visit to a medical genetic consultation. It's not fun to talk about, but there are - although very rare - situations when, based on pedigree genetics alone, they come to the conclusion that the fetus is affected by a disease incompatible with life. In this case, of course, termination of pregnancy is recommended. However, we repeat, these cases are very, very rare. As a rule, specialists in medical genetic consultation do not engage in diagnosis, but in assessing the risk of having a child with severe anomalies and, based on this assessment, recommend one or another method of prenatal diagnosis. Further, the decision is made depending on the results of the study. Only a specialist can decide how high the risk of giving birth to a child with developmental defects really is. Do not rush to have an abortion if you read in the annotation that the drug you took at the very beginning of pregnancy is not recommended for use during this period; if you took alcohol, drugs or suffered an acute respiratory viral infection, took an x-ray during pregnancy, etc. Be sure to contact a medical genetic consultation, where they will be able to correctly assess the real risk and recommend the necessary set of studies.

3. You had a child with a congenital malformation

The best way to cope with psychological shock is to try to obtain maximum information about the nature of the developmental defects. Make sure your child is consulted by a geneticist. It is highly desirable that a sick child undergo a cytogenetic study (analysis of a karyotype - a set of chromosome characteristics). The more information about a sick child is obtained, the more effective the treatment will be and the more accurately it will be possible to establish a prognosis for the future. It is better to seek final medical and genetic consultation regarding the prognosis for the future after 2-3 months, when psychological tension has subsided and the spouses will be able to perceive this kind of information more objectively. For most families, subsequent pregnancies are successful. The possibilities of prenatal diagnosis add confidence in a successful outcome for both doctors and patients.

The nuclei of somatic (non-sex) cells contain 23 pairs of chromosomes, of which one pair is sex chromosomes. In women, this pair consists of two identical chromosomes, conventionally called X chromosomes; in men, these chromosomes are different - the X chromosome and the Y chromosome. Non-sex chromosomes are called autosomes. In germ cells there are half as many chromosomes - not 23 pairs, but 23 pieces. During fertilization, the nuclei of the egg and sperm merge, and the future human receives a full set of chromosomes, thus inheriting both maternal and paternal characteristics. Chromosomes are made up of genes. A pair of genes is responsible for each trait in the body - “mother’s” and “father’s”. (The exception is the XY pair of sex chromosomes in men: not all genes on the X chromosome have “partners” on the Y chromosome.) In each pair, one gene is dominant (dominant gene), i.e. the variant of the trait caused by it appears, the other one is “inferior” (recessive gene). Under unfavorable circumstances, both genes in a pair or one of them may turn out to be carriers of a pathological trait. In the first case, their “owner” is undoubtedly sick. If we are dealing with only one “sick” gene, two options are possible: (1) a dominant gene is “responsible” for the disease - then its carrier is sick; (2) the carrier of a pathological trait is a recessive gene - then the person is healthy (more precisely, as doctors say, phenotypically healthy, i.e., if there is a “sick” gene in the genotype, there are no manifestations of the disease). Autosomal dominant type of inheritance The carrier of a pathological trait is a dominant gene contained in an autosome (non-sex chromosome). With this type of inheritance, the birth of a sick child from healthy parents is possible only as a result of a new mutation. Such an event is generally considered to be accidental and the risk of recurrence is low. Another situation is when one of the parents suffers from a disease or has a developmental defect with an autosomal dominant type of inheritance. Moreover, half of the children may inherit such a defect or disease; boys and girls are equally susceptible to the disease. Such developmental defects have varying degrees of severity; in some cases they are mild and, after successful correction, do not interfere with normal life. Autosomal recessive mode of inheritance The carrier of a pathological trait is a recessive gene contained in an autosome. With an autosomal recessive inheritance mechanism, the situation looks paradoxical - healthy parents suddenly give birth to a child with developmental defects, often severe and even incompatible with life. The reason is the latent carriage of mutant recessive genes by both spouses. Just as in the autosomal dominant type, boys and girls are equally susceptible to the disease. The probability of having a sick child again in this marriage is 25%, which is considered a high genetic risk. If there is no reliable prenatal diagnosis of such a disease, then spouses are not recommended to continue childbearing in this marriage. Sex-linked recessive inheritance Sex-linked developmental defects are mainly caused by recessive mutations in the female sex chromosome (this type of inheritance is also called X-chromosomal). This trait is always transmitted through the mother, a carrier of the recessive “sick” gene (i.e., the woman herself is healthy). Almost all those affected are men (the affected gene on the X chromosome does not have a “partner” on the Y chromosome that could dominate it). A sick man never transmits the disease to his sons (after all, they receive from him a “healthy” Y-chromosome, and not a mutant X-chromosome), but all his daughters will be carriers of the “fatal” gene. We have deliberately described the types of inheritance schematically to give the reader a general understanding of the essence of these mechanisms. In fact, everything is much more complicated - much less unambiguous and definite.

And congenital non-hereditary.

Congenital hereditary developmental anomalies

As a result of many years of research in Russia and abroad, it has been established that about 20% of all congenital developmental anomalies (deformities) are hereditary and appear during the embryonic development of the fetus from parents who have abnormalities in chromosomes and genes. About 10% of anomalies are caused by bad habits and the use of certain substances (use of alcohol, drugs and some medications), poor ecology, and for the remaining 70% of deformities the causes have not been established.

Every woman wants to give birth to a healthy and beautiful child. In order to avoid congenital developmental anomalies, it is necessary to know the causes of their occurrence.

Currently, hundreds of chemical reagents have been identified that can cause disruption of chromosomes or genes in parents and provoke intrauterine deformities of the fetus.

Developmental anomalies can be different: the complete absence of an organ (for example, a kidney), underdevelopment of an organ (small size and weight), too much development of an organ (for example, too large a size and weight of the brain - macrocephaly). In all cases, these deviations have a detrimental effect on the physical and mental development of the child, and often lead to his death.

In addition, the structure (narrowing of the intestines, esophagus, underdevelopment of heart valves, etc.), shape and number of organs (for example, a decrease or increase in the number of fingers and toes, the appearance of extra internal organs, for example, an extra kidney and etc.) or insufficient number of paired organs (for example, one eye or one kidney).

The result of these deviations is early childhood mortality (up to 20% of all child deaths). It has been noted that in recent years the percentage of intrauterine fetal anomalies has been steadily increasing.

Not all childhood developmental abnormalities appear at an early age. Some of them appear only at puberty or later.

In addition, anomalies can manifest themselves in metabolic disorders of the child - in the absence of any enzyme, etc.

All disorders of intrauterine development of a child are conventionally divided into 5 groups: anatomical, physiological, functional, biochemical and mental.

Of all the disorders of intrauterine development of the fetus, the most dangerous are diseases associated with a violation of the structure of chromosomes or their number in cells. Most of these anomalies lead to fetal death or the birth of a non-viable child.

Down syndrome

This is the most common hereditary disease (approximately 1 in 800 births). It is a consequence of a violation of the number of chromosomes in cells (instead of 46 chromosomes, a child has 47 chromosomes in his genotype). This disease affects both girls and boys.

Most often, a child with Down syndrome is born to an elderly mother or father (over 40 years old). This syndrome is detected in the early stages of pregnancy using ultrasound and other methods, but the accuracy of the examination is 95% (the remaining 5% is an erroneous diagnosis). To date, the most accurate diagnosis of this disease (up to 99.8%) is obtained from the study of amniotic fluid. If this pathology is detected in the fetus, the parents themselves have the right to decide whether to keep this child or not.

Characteristic external signs of Down syndrome: a fold at the inner corner of the eye, a flat face and back of the head, a small nose, a large tongue, an open mouth, a short neck and skin fold on the neck, shortened limbs and fingers, muscle weakness, and squint may occur. Such children also have heart and duodenal defects and mental retardation.

Expectant mothers need to know that before having an abortion if a child is diagnosed with Down syndrome, they need to think carefully. Such children are very affectionate, kind, and the degree of their dementia varies greatly. Currently, such children, although more slowly than healthy children, can be taught using special methods. They begin to walk, talk, read and write. People with this disease marry and live into old age, but such people need to keep in mind that the likelihood of their children developing this syndrome increases to 50%.

Edwards syndrome

This is the second most common hereditary disease after Down's disease, associated with the presence of an extra chromosome in cells. With this disease, the fetus develops multiple defects. Most often, this syndrome occurs in children born to elderly mothers, mainly girls. Such a child has a violation of the size of the bones of the skull, sternum, foot, and body proportions. In addition, the external auditory canal may be absent, there may be heart and blood vessel defects, abnormalities in the development of the brain, cerebellum, and mental retardation. These children, as a rule, are not viable and die before the age of 3 months, rarely before 1 year. Very rarely such children live longer, but they are all oligophrenic (mentally retarded).

Klinefelter syndrome

This is a fairly common hereditary disease caused by changes in the number of chromosomes. This syndrome develops only in boys born to older mothers. This disease appears only during the child’s puberty; he has underdevelopment of the testicles, there are no or a reduced number of sperm in the semen, and infertility develops. The boy’s external development follows the female type: narrow shoulders, wide pelvis, long legs, enlarged mammary glands. Mental and mental abnormalities may occur. If you notice the first signs of this disease, you should immediately consult a doctor to begin treatment (most often hormonal).

Hemophilia

This hereditary disease is passed on to the child from the mother. This disease occurs only in boys. In hemophilia, blood clotting is impaired. With appropriate treatment, this disease is not a death sentence.

Cystic fibrosis

This is the most common hereditary systemic disease.

Cystic fibrosis affects the respiratory and digestive systems, as well as the liver, pancreas and gonads. Mucus accumulates in large quantities in the body, a painful cough occurs, wheezing in the lungs, the heart is affected, the pancreatic ducts are blocked, diarrhea is replaced by constipation, the stomach is swollen, children grow poorly and gain weight, the limbs are thin, with a characteristic shape of the fingers, the chest is deformed, the skin tastes salty (if you lick it). The mental development of such patients is normal, and sometimes even above average. This severe congenital disease is currently not completely curable, but with proper supportive therapy, such patients can live a long and full life. They must receive certain medications throughout their lives.

Phenylketonuria

This disease is a consequence of a child’s metabolic disorder of the amino acid phenylalanine, resulting in a delay in his physical and mental development. This disease is detected in the first days of a child’s life. It is not a sentence. By prescribing a special diet, the development of this disease can be prevented.

Colorblindness

This hereditary disease is transmitted from mother to son and manifests itself in the fact that the child does not distinguish between some colors (that is, color vision is partially impaired), most often red and green. This disease has no cure.

"Harelip"

This developmental anomaly consists of a non-fusion of the upper lip, which interferes with the baby's sucking. Treatment is surgical, in the first months of the child’s life. This deformity can be provoked by a lack of food in a pregnant woman.

"Cleft palate"

This is a non-fusion of the upper jaw and hard palate, as a result of which the oral cavity is not separated from the nasal cavity. This defect causes food to enter the windpipe and nasal cavity. Very often, a cleft palate is observed together with a cleft lip. Treatment is surgical. The cause of this abnormal development of the child may be a lack of food in the pregnant woman.

Polydactyly

Polydactyly - the presence of extra fingers or a lack of them on the hand or foot, fusion of the fingers with each other, shortening or absence of limbs. Treatment is surgical and prosthetics.

Anencephaly, microcephaly, hypercephaly and hydrocephalus

All these are anomalies of brain development. These developmental anomalies can be provoked by a deficiency in the woman’s body or by rubella, measles and some other diseases suffered by the mother during pregnancy (especially in the first weeks after conception).

If anencephaly (absence of cerebral hemispheres) is detected in a child, the pregnancy is terminated at any stage.

Confusion of twins (so-called Siamese twins)

This is one of the most severe anomalies of intrauterine development of fetuses. Twins can be connected by any part of the body (pelvis, head, etc.), their circulatory and other organ systems can be isolated or connected, one twin can be normally developed, while the other is underdeveloped. These children usually die at an early age. In case of fusion only by soft tissues and in case of independent functioning of each child, the treatment is surgical.

Umbilical and spinal hernias

A navel hernia is an exit from the cavity under the skin of the intestine. Such hernias can go away on their own; in severe cases, treatment is surgical.

Spina bifida are the most severe malformations of the fetus. Most children suffering from these developmental defects die, and those who survive experience paralysis, therefore, if such defects in fetal development are detected, premature termination of pregnancy is indicated.

Malformations of the heart and blood vessels

The cause of these fetal malformations may be a viral or bacterial disease suffered by the mother during pregnancy, as well as a lack of oxygen.

These heart defects, depending on their severity, are treated with medication or surgery.

In severe cases, the child dies in utero or immediately after birth.

All anomalies in the development of the fetal skeleton are caused by genetic or chromosomal abnormalities in the cells of the unborn child.

In addition, other hereditary diseases (Hirschsprung's disease, Huntington's disease, Ponter's disease, von Willebrand's disease, Tay-Sachs disease, Fraser syndrome, Patau syndrome, Turner syndrome, marble disease and many others) are very rare. Developmental defects also include various birthmarks, some congenital skin diseases, congenital hip dislocation, cranial hernias and others.

Currently, more than 3.5 thousand hereditary developmental anomalies are known. It has been established that more than 5% of all children born are born with various pathologies.

All considered chromosomal and genetic hereditary diseases are practically independent of the external environment.

Another group hereditary diseases are those to which the child has a hereditary predisposition, but clinically this disease manifests itself only under certain environmental conditions. These diseases include: diabetes, psoriasis, stomach ulcers, hypertension, gout and some others.

Some hereditary diseases appear only in old age (for example, Alzheimer's disease, atherosclerosis, gout).

If relatives in your family have had various serious hereditary diseases, you must undergo special medical genetic examinations before conceiving a child.

The risk of developing a hereditary disease and various deformities of a child in closely related marriages increases many times over.

There is no need to be alarmed: the congenital hereditary diseases considered are very rare (most often 1 child per several thousand births). Every expectant mother, from the first days of pregnancy until birth, worries about how her baby will be born and whether he will be healthy.

The description of all these developmental defects is given not with the aim of scaring you, but so that you understand that the health of your baby is almost entirely dependent on you.

If you eat properly and your unborn baby receives all the substances necessary for his life and development (proteins, fats, carbohydrates, vitamins, especially folic acid, and mineral salts), the likelihood of having a sick child is negligible.

Folic acid is necessary for proper cell division, including at the embryonic stage, the formation and growth of all internal organs, the metabolism of the fetus, and its hematopoiesis; in addition, it prevents premature birth and miscarriages. In addition, if you lead a healthy lifestyle, do not smoke, do not use drugs or alcohol, and your genetics do not have severe hereditary diseases, then the risk of giving birth to an unhealthy child is practically absent, and you can rest assured about your unborn baby.

If your relatives have any disease that is inherited, you need to be examined by a doctor and begin timely treatment to prevent this disease or promptly terminate the pregnancy in especially severe cases. Women over 40 years of age should avoid pregnancy.

At the present stage of development of medicine, most of the listed developmental anomalies are detected in the early stages of pregnancy.

The most important thing for preserving the health of the mother and the unborn baby is to register with the antenatal clinic as early as possible, visit it regularly and follow all your doctor’s orders.

Tests to detect pathology become a rather serious test for the expectant mother. They are usually carried out from 10 to 16 weeks, that is, in the first trimester. In some cases, doctors are forced to diagnose congenital or genetic abnormalities, due to which termination of pregnancy is recommended. Which is the most dangerous pathology of early pregnancy, How can it affect a child and are there any chances of avoiding it?

Read in this article

Reasons for early screening

Unfortunately, many couples have to undergo tests at the stage of intrauterine development of the fetus. The thing is that, under the influence of certain factors, the child begins to develop irreversible genetic abnormalities. The reasons for the development of defects may be:

• bad ecology;
• exposure to toxic chemicals, radiation, medications;
• transmission of abnormalities from parent to fetus (hereditary family diseases) or acquisition of high-quality genetic information of a couple after combining;
• consanguineous marriages;
• women who have had sad experiences with previous pregnancies, including repeated miscarriages, stillbirths, infertility of unknown etiology;
• women under 18 years of age and “old mothers” over 35 years of age;
• infectious diseases of the mother, disorders of the endocrine and immunological systems.

In the presence of these factors, the chances of developing gene mutations in the fetus are much greater. Detection of pathologies in early pregnancy allows you to detect non-viable embryos. This mainly leads to missed abortion or the birth of children with disabilities.

Types of genetic abnormalities in children

Genetic defects are divided into acquired and congenital ( trisomy ). The latter are more common, the most famous of them being Down syndrome. They can also simply be passed on from generation to generation. For example, if a grandmother was under the influence of toxic substances for a long period of time, it is not a fact that this will affect her child. The results of the toxins may already appear in her grandchildren. Pathology of pregnancy can either completely change the structure of a future person, his physiological abilities, or only slightly damage certain organs.

Down syndrome

It manifests itself in the presence of a third chromosome, despite the fact that there are usually two. In addition to external differences, the most important danger for children with such deviations is considered to be heart defects, which occur in 40% of cases. Also, scientists have long established a pattern between the age of the mother and the birth of a child with Down syndrome: after 45 years, every couple out of 14 who conceives has a Solar Child, that is, a baby with trisomy of the 21st chromosome. As for the father's age, it affects the fetus to a lesser extent.

How Down syndrome manifests itself externally

Edward's syndrome and Patau's syndrome

If a geneticist identifies such types of abnormalities in the fetus, parents will have nothing to encourage: in 90% of cases, babies die in the first year of life, while heart defects occur in 80% of them.

Treacher Collins syndrome

Occurs in the early stages of fetal development as a result of gene mutation. A rather rare deviation, which manifests itself in gross deformations of the facial part of the skull, absence or curvature of the ears, hearing impairment, problems with eating and swallowing in general, and the respiratory tract. However, the child develops on par with his peers.

Angelman syndrome

Deviation is extremely rare, however, it cannot be excluded either. Manifests itself in developmental delays and epileptic seizures. The most famous child with this genetic disorder was born to actor Colin Farrell.

Since the birth of Sunny children has become quite common, we recommend that you read the article. From it you will learn how the pathology manifests itself, what tests will help identify the deviation, and you will also learn advice for parents who are faced with such a diagnosis and do not know what to do.

Results of the influence of an unfavorable environment on the fetus

Fetal pathology in early pregnancy may also arise under the influence of the external environment. That is, a completely healthy embryo, under the influence of certain factors, acquires pathological deviations. Mostly at risk are women living near industrial zones with factories, chemical plants, working with chemicals and heavy metals, and in laboratories.

Under the influence of all these factors, the fetus may experience slow development, deformities, and disturbances in the functioning of vital organs. But, the worst thing is, with long-term influence harmful substances the fetus may die in the womb. That is why a woman should be extremely careful during these already difficult nine months of waiting. Particular attention should be paid to the first trimester, since during this period the embryo is most vulnerable.

Fetal pathologies that develop due to improper lifestyle

Smoking, drugs, alcohol are far from the best companions for an expectant mother. Even at the stage of pregnancy planning, they must be abandoned so that the body has time to cleanse itself and gain strength to bear a healthy child.

The effect of nicotine on the fetus

Under the influence of nicotine, the fetus begins to develop hypoxia (oxygen starvation), which ultimately leads to damage to important vital organs, the meninges and lungs. As statistics show, children are born and grow weaker than their peers, get sick more often and lag behind in physical development. In addition, nicotine significantly increases the risk of stillbirth, miscarriages, bleeding, etc.

The effect of alcohol on the fetus

But it poses the greatest danger to the fetus. Such parents are much more likely to have a child with disabilities and genetic pathologies. The main thing that alcohol affects is the brain. In this regard, the child may later be diagnosed with mental retardation, and in some cases, severe mental disorders.

Statistics are a stubborn thing. According to the latest data, mothers who regularly drink alcohol had spontaneous abortions in 29%, miscarriages and premature births in 22% of cases, children were born premature in 34% of cases, and 26% of pregnant women suffered from toxicosis. In general, pathology during childbearing was identified in 46.5% of cases, and problems during childbirth in 56% of cases.

It is worth noting that children from an alcoholic mother are often born with alcohol syndrome. That is, in fact, the child is already dependent on alcohol, and his body is affected by toxins.

Effect of drugs on the fetus

Children of drug addicts are at greatest risk. The birth of a child with genetic abnormalities from a mother who used barbiturates and other drugs that poison the body is very high. But it is worth noting that if parents regularly “sat on the needle,” that is, they mainly took heroin and cocaine, then with a high probability they will not see their child alive at all, since with a high degree of probability he will die in the womb. If the fetus falls into that small percentage of survivors, in this case it may develop mental disorders, serious illnesses, due to which it will remain disabled for life. With a high degree of probability, children of drug addicts will never catch up with their peers in development.

Moms! Think about it! Is it really possible that imaginary pleasure can forever deprive you of the joy of motherhood, and your baby of a happy and healthy future?

Pathologies developing under the influence of intoxication

Quite often, a child becomes a “spontaneous gift”, before which the parents do not undergo the necessary examinations for the presence of infections. However, the fetus is affectedgenital and extragenital (viral and bacterial, not related to the genital organs) infections. Each of them poses a serious threat to the embryo.

But, no matter how paradoxical it may sound, signs of pregnancy pathology They can also give it to absolutely healthy mothers who have had influenza. Depending on the severity of the disease in the early stages (up to 12 weeks), the embryo either survives and develops normally, or dies in the womb. In the second and third trimester, the consequences of suffering from influenza can be all sorts of pathologies with the placenta, which will ultimately lead to hypoxia andfetal malnutrition.

The following diseases are also considered dangerous:

• listeriosis;
• syphilis;
• tuberculosis;
• gonorrhea;
• cytomegaly and;
• hepatitis (A, B, C, D);
• HIV infection.

Each of the diseases poses a serious threat. For example, with such a minor problem for the mother as rubella, in the first 90 days after conception, doctors will suggest an artificial termination of pregnancy. If the child is kept, there is a high risk of developing deafness, glaucoma, and bone damage.

One of the most dangerous diseases is toxoplasmosis. It develops in pregnant women who regularly come into contact with cats. The result will be hydrocele of the brain, meningoencephalitis, microcephaly, eye and central nervous system damage. That is why it is better to give your pet to another family for a while. It is worth noting that it is also undesirable for small children to have regular contact with a cat.

If the parents have hepatitis, then the chances are almost 50*50: in 40% of cases the child can be cured, and in 40% the children die before the age of two. Even seemingly harmless herpes, which affects more than 30% of people on the planet, if the fetus is infected, can lead to the development of cirrhosis, shortened arms and legs, blindness and other unfavorable abnormalities.

This is why it’s worth getting tested when planning a pregnancy. , to minimize the risk of congenital anomalies and loss of the child.

Diagnosis of fetal pathology development

Determining congenital and acquired fetal pathologies is a complex process. P first blood screening The pregnant woman will be prescribed at 12 weeks, then repeated examinations will be carried out at 20 and 30 weeks. The mother will be tested for developmental defects. In this case, the examination will be carried out on absolutely everyone, regardless of whether the woman is at risk or not. The most popular screening test is the alpha-fetoprotein test.. It is recommended to be carried out before the 12th week of pregnancy, the optimal period is 10-11 weeks. The reliability of the results reaches 95%. A mandatory addition is Ultrasound for pathology of the fetus and uterus.

Chorionic villus biopsy

This blood test for pathology allows you to determine any genetic abnormalities with high accuracy. And it is he who scares the expectant mother most of all. After all, you will have to take it by handa tiny amount of tissue (chorionic villi) from the fetal placenta, and for this it is necessary to either pierce the abdominal cavity with a thin needle or remove the material through the cervix.

It is worth noting that for a pregnant woman the procedure is unpleasant, but practically painless. The probability of harming the fetus or causing a miscarriage is extremely minimal, no more than 1%! After the procedure, slight pain and slight bleeding are possible. The alarm should only be sounded if heavy bleeding begins, contractions are felt, or serious ailments occur.

Amniocentesis

An analogue of Charion biopsy, only in this case amniotic fluid is taken. It is believed that it is safer, although in fact the risks are approximately the same: the probability of adverse reactions after the procedure is 0.5% -1%. But one of the disadvantages is that it is carried out only from the 15th week after conception.

The results of both the first and second analyzes will be received in two to three weeks. To refuse them is to potentially be ready to give birth to a child with genetic abnormalities.

Fetal ultrasound

If previous analysis for fetal pathology allows you to identify gene abnormalities, then ultrasound allows you to exclude congenital pathologies. However, it can only be carried out if the specialist is experienced specifically in issuesprenatal diagnosis of congenital malformation, as well as from 20 weeks after conception. It is not recommended to save money by turning to cheaper diagnostic centers. It is likely that they are using outdated equipment, with which it is impossible to detect pathology.

Unfortunately, medical indications for termination of pregnancy (congenital and acquired during the development of pathologies) can usually be disputed. If a mother decides to give birth even despite doctors’ warnings about possible anomalies and threats to the child’s life, then her pregnancy will be under vigilant monitoring throughout the entire period. If she conceives again, the woman will automatically be placed in a risk group and will be forced to take all tests to determine pathologies.