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Congenital heart defects. Development of the fetal heart. Features of the structure and functioning of the heart in the fetus

Congenital heart defects. Development of the fetal heart. Features of the structure and functioning of the heart in the fetus

30.07.2019

Article publication date: 03/02/2017

Article updated date: 12/18/2018

From this article you will learn: when the fetal heart begins to beat, how to listen to the heartbeat. At what frequency should the embryo's heart beat? What do deviations from the norm indicate?

The heart is one of the organs that is formed first in the embryo. It begins to form at 3 weeks intrauterine development.

Already at 4 weeks, the primitive heart of the embryo begins to beat. But it is possible to register a heartbeat at this stage only with the help of transvaginal ultrasound.

Intrauterine development of the heart

The cardiovascular system is established already in the 2nd week of pregnancy.

Click on photo to enlarge

The primary heart is formed at 3 weeks. At this stage, it still does not have chambers, but is a hollow tube. It is already capable of contracting.

By the middle of the 4th week, the tube turns into a still underdeveloped heart, consisting of 2 chambers: the atrium and the ventricle. In addition, during this period, the conduction system is formed in the heart. Contractions of this structure can already be called a heartbeat.

At the end of the 4th week, one atrium is divided into right and left by the interatrial septum.

At week 5, the interventricular septum begins to develop.

At week 8, the formation of the heart ends: it already consists of 4 chambers.

From the above it is clear that the first trimester of pregnancy is very important. It is during this period that congenital heart defects can occur. The causes are usually bad habits, taking medications that are toxic to the fetus (for example, antibiotics), infectious diseases, and frequent stress. Therefore, it is better to plan pregnancy in advance to avoid negative effects on the embryo initial stage its development.

Listening to the fetal heartbeat

This can be done using:

transvaginal ultrasound;
transabdominal ultrasound ( classic version ultrasound);
stethoscope.

Listening to the fetal heartbeat with a stethoscope

At what time do doctors record the fetal heartbeat?

Methods for detailed examination of the fetal heartbeat:

Cardiotocography (CTG) - allows you to detect oxygen starvation. This procedure is carried out at 32 weeks and before birth. Indications for extraordinary CTG: infection mother, accompanied high temperature body, oligohydramnios or polyhydramnios, delayed fetal development, post-term pregnancy.
Fetal echocardiography (fetal echocardiography, fetal echocardiography). It can be used to identify heart defects. Can be performed starting from the 18th week of pregnancy. Indications: bad habits or taking antibiotics in the first trimester, heart defects in the expectant mother, her direct relatives or her previous children, age over 35 years, diabetes, systemic lupus erythematosus, rubella, toxoplasmosis, Lyme disease or herpes during pregnancy.

What does a weak or absent heartbeat indicate?

A weak heartbeat in the first trimester is a sign of a threat of spontaneous abortion. In this case, an additional examination is carried out and treatment is prescribed, depending on the reason that created the threat of miscarriage. The woman may be put on bed rest, hormonal drugs, natural sedatives, vitamins E and C, antispasmodics or corticosteroids. Follow all the recommendations prescribed by your doctor, and your future pregnancy will proceed normally.

If during a transabdominal ultrasound at 6 weeks of pregnancy the doctor does not register a heartbeat, but sees the fertilized egg and embryo, the examination is postponed for 1–2 weeks. This is explained by the fact that it is very difficult to calculate the exact day of conception of a child, especially with irregular menstrual cycle, and the timing calculations turned out to be incorrect. On a repeat ultrasound, a heartbeat is usually already present. If it is not there, a frozen pregnancy is diagnosed.

If the ultrasound specialist does not register the heartbeat and does not see the embryo, this indicates the so-called anembryony - the absence of an embryo in fertilized egg. In this case, to be sure, a repeat examination is scheduled in 1–2 weeks. If the ultrasound results are the same, the diagnosis is confirmed.

In both cases (both with frozen pregnancy and with anembryonia), curettage of the uterus is prescribed.

If the doctor does not register a heartbeat later in pregnancy, this indicates intrauterine death of the baby (antenatal death). To remove the dead fetus from the body, artificial birth is performed.

Can a woman feel the fetal heartbeat?

Despite the fact that the period when a fetal heartbeat appears is only 4 weeks, the expectant mother will not feel a heartbeat either in the second or in the ninth month.

What women often mistake for the baby's heartbeat is the pulsation of their own aorta. It can be felt in the abdomen or lower back. Occurs due to increased pressure in this vessel.

If you experience palpitations in your stomach or lower back during pregnancy, contact your gynecologist. You may also need to consult a cardiologist.

Normal fetal heart rate

A diagnosis is not made based on minor deviations from the norm. Of clinical significance is an increase in heart rate to 200 beats per minute or more (tachycardia) or a decrease to 100 beats per minute or less (bradycardia) starting from 6–8 weeks.

Possible causes of fetal tachycardia:

Unstable emotional condition future mother.
Chronic fetal hypoxia (due to pathologies of the placenta or umbilical cord or malformations of the embryo itself).
Stuffiness in the room where a pregnant woman spends most of the time.
Iron deficiency in the mother's blood.

The cause of bradycardia is chronic hypoxia. If the heart rate is 80 beats per minute or less, the risk of spontaneous abortion is high.

The development of the human embryo can generally be divided into three stages:

the period from the moment of fertilization of the egg until the moment the developing embryo is implanted into the uterine wall and begins to receive nutrition from the mother;
formation of main organs; the embryo acquires the features of a human body (fetus);
The specialization of the organs and systems of the fetus is completed, and it acquires the ability of independent existence.

Let's look at the individual stages of embryo development:

When does the embryo implant in the uterus?

It has been established that 6-7 days after fertilization are the time when the embryo attaches to the uterine mucosa (implantation process). During implantation, the embryo is completely immersed in the tissue of the uterine mucosa. The process when the embryo attaches to the wall of the uterus lasts an average of 48 hours.

There are 2 stages of implantation: adhesion (adhesion) and penetration (invasion). In stage 1, the trophoblast attaches to the uterine mucosa and differentiation of two layers occurs in it: cytotrophoblast and plasmodiotrophoblast.

In the second stage, the plasmodiotrophoblast produces proteolytic enzymes that destroy the uterine mucosa. Thus, the trophoblast villi are introduced into the epithelium, and then, successively, into the connective tissue and walls of blood vessels. Trophoblast begins to receive nutrition and oxygen from maternal blood

The period when the embryo attaches to the uterine mucosa is the first critical period of its development, and upon successful completion of this stage, the stage of laying down extra-embryonic organs begins.

When is the embryo visible?

The seventh week from the moment of conception is the period when the embryo is clearly visible: the head, torso and its limbs are clearly visible. Registration and assessment of the condition of the embryo and fetal sac using ultrasound allows you to confirm the presence of pregnancy, determine the location of the embryo in the uterus, and the gestational age.

When does the embryo's heart begin to beat?

There are several answers to the question “when does the embryo’s heart begin to beat”:

on the twenty-second day (5 weeks) from the moment of fertilization. The circulatory system of the embryo begins its development at 3 weeks of pregnancy. At this time, the wall of the vascular tube in the bend of the loop of the germinal circle of blood circulation makes the first contraction. During the fourth week, the pulsation becomes increasingly stronger and more regular. The pumping of blood through the vessel begins and the fetus transitions to a type of blood circulation independent of the mother - its own type of blood circulation with a single-chamber heart.
in the sixth week of development. That is, this is the period when the embryo’s heart beats during echoscopy using modern ultrasound machines, and during this period it is already possible to register contractions of the embryo’s heart. By this time, partitions appear in the hollow muscular-connective tissue tube, the heart increases in volume and turns into a two-chamber one. Until the ninth week of embryo development, the formation of heart structures occurs: its atria, ventricles and the valves separating them, inflow and outflow vessels, the conduction system and the formation of feeding blood vessels.
end of the second month of embryo development. At this stage, the heart of the embryo becomes four-chambered and acquires a structure completely similar to that of a human. The time from the fourth to the eighth week after fertilization is the most dangerous in terms of the possible formation of defects cardiovascular systems s. The final formation of the fine structures of the heart is almost complete by 22 weeks. In the future, only the accumulation of muscle mass of the heart muscle occurs, and an increase in the supplying vascular network of both the heart itself and other organs of the fetus.

This is not only an exciting stage for parents, but also a responsible one.

There are critical periods when the process of embryogenesis is associated with high risks of the influence of negative factors that contribute to disruption of the normal formation of organs and tissues with the development of congenital defects. One of these critical periods is the stage when the heart is formed in the embryo and fetus.

Embryogenesis

The cardiovascular system is one of the first to develop, due to the need for blood supply to other organs and tissues. This occurs at 2–6 weeks of gestation.

After the fusion of germ cells, a complex and lengthy stage of embryogenesis is initiated.

The formation of the heart begins in the second week, when 2 heart tubes are formed, which merge together and embryonic blood enters there. At 3-4 weeks, significant growth of the tube is observed, which is expressed in its enlargement and change in shape.

Structures such as the sinus venosus, primary ventricle (venous section), primary atrium, and common truncus arteriosus begin to form. During this period, the heart is a single-chamber structure ─ and the first contractions appear.

At the end of the 4th week, the developing heart has a two-chamber structure. This occurs as a result of an increase in the arterial and venous sections and the appearance of a constriction between them. Blood circulation is represented only by a large circle, and a small one is formed as the organogenesis of the bronchopulmonary system occurs.

At 5-6 weeks, the interatrial septum is formed, and the heart becomes three-chambered, and later the interventricular septum is formed, the valve apparatus is formed, the common aortic trunk is divided into the pulmonary artery and the aorta. This is how the organ becomes four-chambered.

At week 7, the construction of the interventricular septum is finally completed, and all further transformations are associated with an increase in size and the development of the conduction system.

Diagnostics

All future parents are concerned about the question of how long it takes to hear the first heartbeats. And for good reason, since this is an important indicator that helps determine how correctly the cardiovascular system is formed and how the embryo and fetus are developing.

For this purpose, several methods are used:

On early stages embryogenesis, ultrasound examination is performed. It makes it possible to hear the heartbeat of the embryo at 5 weeks when using a transvaginal sensor or at 7 weeks when using a transabdominal one. It should also be mentioned that the frequency of contractions varies depending on the gestational age.

Auscultation with an obstetric stethoscope is a method that comes from antiquity, but has one drawback. It is possible to listen to heart sounds no earlier than the beginning of the third trimester.

During this period, every time a woman visits an obstetrician-gynecologist, this examination is carried out. It allows the doctor to judge the progress of pregnancy and the condition of the baby in the womb. For this purpose, an external obstetric examination is first performed, and then the stethoscope is placed in the place of best listening to the heartbeat.

Cardiotocography is a method of recording the work of the fetal heart and the tone of the uterus with the results displayed on a calibration tape. Diagnosis can be carried out from the 22nd week of pregnancy, however, according to orders, it is prescribed at least 3 times in the third trimester and during the birth process.

This allows you to monitor not only the development of the heart and cardiovascular system as a whole in the fetus, but also the condition during childbirth, and choose delivery tactics. When conducting the study, the following indicators are assessed:

The normal basal rate is 120-160 per minute.
Rhythm variability – 10─25 contractions per minute.
Presence of decelerations (decrease in heart rate rhythm by 30 or more in half a minute).
The presence of 2 or more accelerations (increase in heart rate by 10–25 per minute during movement, contraction of the uterus) for 10 minutes during recording.

In assessing the development of an embryo or fetus, it is important not only to catch the moment when the first heartbeat appears.

It is necessary to control the process of proper organogenesis in order to timely diagnosis congenital anomalies.

For this, echocardiography is performed, which allows you to calculate the size of the heart and large vessels, visualize cardiac structures, as well as existing abnormalities.

With Doppler ultrasound, it is possible to assess blood flow.

If pathological abnormalities are detected, the issue of termination of pregnancy or surgical intervention is decided immediately after birth.

When fetal heartbeat appears, possible problems

From this article you will learn: when the fetal heart begins to beat, how to listen to the heartbeat. At what frequency should the embryo's heart beat? What do deviations from the norm indicate?

The heart is one of the organs that is formed first in the embryo. It begins to form at the 3rd week of intrauterine development.

Already at 4 weeks, the primitive heart of the embryo begins to beat. But it is possible to register a heartbeat at this stage only with the help of transvaginal ultrasound.

Intrauterine development of the heart

The cardiovascular system is established already in the 2nd week of pregnancy.

Click on photo to enlarge

The primary heart is formed at 3 weeks. At this stage, it still does not have chambers, but is a hollow tube. It is already capable of contracting.

By the middle of the 4th week, the tube turns into a still underdeveloped heart, consisting of 2 chambers: the atrium and the ventricle. In addition, during this period, the conduction system is formed in the heart. Contractions of this structure can already be called a heartbeat.

At the end of the 4th week, one atrium is divided into right and left by the interatrial septum.

At week 5, the interventricular septum begins to develop.

At week 8, the formation of the heart ends: it already consists of 4 chambers.

Listening to the fetal heartbeat

This can be done using:

transvaginal ultrasound;
transabdominal ultrasound (classic version of ultrasound);
stethoscope.

Listening to the fetal heartbeat with a stethoscope

At what time do doctors record the fetal heartbeat?

Methods for detailed examination of the fetal heartbeat:

Cardiotocography (CTG) - allows you to detect oxygen starvation. This procedure is carried out at 32 weeks and before birth. Indications for extraordinary CTG: maternal infectious disease accompanied by high body temperature, oligohydramnios or polyhydramnios, delayed fetal development, post-term pregnancy.
Fetal echocardiography (fetal echocardiography, fetal echocardiography). It can be used to identify heart defects. Can be performed starting from the 18th week of pregnancy. Indications: bad habits or taking antibiotics in the first trimester, heart defects in the expectant mother, her direct relatives or her previous children, age over 35 years, diabetes mellitus, systemic lupus erythematosus, rubella during pregnancy, toxoplasmosis, Lyme disease or herpes.

What does a weak or absent heartbeat indicate?

A weak heartbeat in the first trimester is a sign of a threat of spontaneous abortion. In this case, an additional examination is carried out and treatment is prescribed, depending on the reason that created the threat of miscarriage. A woman may be prescribed bed rest, hormonal medications, natural sedatives, vitamins E and C, antispasmodics or corticosteroids. Follow all the recommendations prescribed by your doctor, and your future pregnancy will proceed normally.

If during a transabdominal ultrasound at 6 weeks of pregnancy the doctor does not register a heartbeat, but sees the fertilized egg and embryo, the examination is postponed for 1–2 weeks. This is explained by the fact that it is very difficult to calculate the exact day of conception of a child, especially with an irregular menstrual cycle, and the calculations of the period turned out to be incorrect. On a repeat ultrasound, a heartbeat is usually already present. If it is not there, a frozen pregnancy is diagnosed.

If the ultrasound specialist does not register the heartbeat and does not see the embryo, this indicates the so-called anembryony - the absence of an embryo in the fertilized egg. In this case, to be sure, a repeat examination is scheduled in 1–2 weeks. If the ultrasound results are the same, the diagnosis is confirmed.

In both cases (both with frozen pregnancy and with anembryonia), curettage of the uterus is prescribed.

If the doctor does not register a heartbeat later in pregnancy, this indicates intrauterine death of the baby (antenatal death). To remove the dead fetus from the body, artificial birth is performed.

Can a woman feel the fetal heartbeat?

Despite the fact that the period when a fetal heartbeat appears is only 4 weeks, the expectant mother will not feel a heartbeat either in the second or in the ninth month.

What women often mistake for the baby's heartbeat is the pulsation of their own aorta. It can be felt in the abdomen or lower back. Occurs due to increased pressure in this vessel.

If you experience palpitations in your stomach or lower back during pregnancy, contact your gynecologist. You may also need to consult a cardiologist.

Normal fetal heart rate

Possible causes of fetal tachycardia:

Unstable emotional state of the expectant mother.
Chronic fetal hypoxia (due to pathologies of the placenta or umbilical cord or malformations of the embryo itself).
Stuffiness in the room where a pregnant woman spends most of the time.
Iron deficiency in the mother's blood.

The cause of bradycardia is chronic hypoxia. If the heart rate is 80 beats per minute or less, the risk of spontaneous abortion is high.

Heart formation

So, new life was born. Whether you wanted it or not, whether the fruit of your love is desired or not - it doesn’t matter anymore. The egg formed in the ovary passed through the tubes, settled in the uterine mucosa, received and merged with the sperm. This is already a fertilized egg that will grow and eventually become your child.

This life, while still only one cell, carries all the information contained in your genes, i.e. the smallest protein molecules, and in your partner's genes. We will return to this later. But now, the cells have merged, and in the first two weeks after conception, the processes of formation of cellular systems begin, which will then turn into tissues and organs.

As the amazing poet Dmitry Kedrin once wrote:

“There is still no trace of nausea or spots.

And your belt is just as narrow, just look in the mirror.

But you, by elusive, secret female signs

I was frightened to realize what was inside you...”

At first, new life has the shape of a disk. Sometimes such a small protein disc can be seen in the yolk of broken chicken egg. It is called an embryo and in the first days it is just a collection of wise cells that know exactly what they need to do. With each subsequent hour there are more and more cells. They connect and fold into certain shapes, first forming two tubes, then merging into one. This tube folds and descends from the primary disk to form a loop called the “primary cardiac loop.” The loop quickly lengthens, significantly outstripping the growth and increase in the number of cells surrounding it, and lies to the right, in the form of such a ring as the ring of a mooring rope, which is thrown onto the bollard when mooring a boat or vessel. This loop normally lies only on the right, in otherwise the future heart will lie not to the left, but to the right of the sternum. And on the 22nd day after conception, the first contraction occurs in the thickened lower part of the loop. The heart began to beat. You can try to remember what happened to the future mother then. What condition was she in? What was happening to her? And, if you, like the vast majority of married and non-family couples, did not pay attention to this, I can guarantee that you will not remember. You will say: “So what?” - and you will be right. As a rule, nothing. But still, think about it. The first days may not solve anything. But the next ones will decide a lot.

The cardiovascular system of the fetus is formed first of all its systems, because the fetus needs its own blood circulation for the full development of its other organs. The development and formation of the cardiovascular system begins in the third week and mainly ends by the eighth week of the embryo’s life, i.e. occurs within five weeks.

We will briefly describe these stages, but now let’s ask ourselves the question: “What is 4–5 weeks of pregnancy today?” The woman is not yet sure whether she is pregnant, especially if she is not looking forward to this event too much. She does not change her lifestyle, habits, sometimes harmful ones. She can work in heavy and hazardous production or do heavy physical work Houses. She can carry a viral infection in the form of influenza on her feet. Usually the couple does not think yet, tries not to think about the future, but it - this future - no longer only lives, but also beats, contracts, grows. But wait to punish yourself - there may be other reasons. More about them later. In the meantime, let us remember: today in the world they believe that a child’s life begins not from the moment of his birth, but from the moment of conception.

So, on the 22nd day, the future heart begins to pulsate, and on the 26th day, independent blood circulation begins in the body of the fetus, whose length is 3 millimeters. Thus, by the end of the fourth week the fetus has a contracting heart and circulation. So far it is one stream, one curved tube, in the bend of which lies the “motor” - the heart. But every minute processes take place in it that lead to final formation. It is very important to understand that these processes flow simultaneously in three-dimensional space and in order for “everything to come together correctly and accurately,” they need to be completely synchronized. Moreover, if this did not happen, i.e. at some point something did not connect where it was needed, the growth and development of the heart does not stop. Everything is going as usual. After all, when some musician in the orchestra suddenly plays a false note, the orchestra will still finish the symphony. But the false sound will fly away and be forgotten, and few will pay attention to it, and the developing heart will remember it. And now the growing septum has nowhere to attach, or the valve has nothing to hold onto. This is how birth defects are formed. In order for the heart to become four-chambered and not two-chambered (as in the third week), it is necessary for its partitions to grow (interatrial and interventricular), so that the common arterial trunk is divided into the aorta and pulmonary artery, so that inside the common ventricle it is divided into right and left so that the aorta connects to the left ventricle so that the heart valves are fully formed. All this happens between the 4th and 8th weeks of pregnancy (at this time the length of the fetus reaches only 3.5–4 cm). By the end of the second month of pregnancy, the “inch” (3.5 cm) embryo is already fully formed. Obviously, the earlier in this process a disruption of normal development occurred, the more the heart is deformed, i.e. the more severe his congenital defect. The later this happened, the smaller the structural change will be and the easier it will be to correct the defect in the future.

Now we’ll try to explain why this could happen, and we’ll try to convince you that it’s no one’s fault.

Quoted from the book by G. E. Falkovsky, S. M. Krupyanko. The heart of a child. A book for parents about congenital heart defects

For patients

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Heart defects in the fetus during pregnancy

The term “congenital heart disease” is a cause for serious concern for parents. The situation becomes more complicated if this diagnosis was made before the baby was born.

If children with congenital heart disease have already been born in the family or the woman is over 35 years old, pregnancy should be planned especially carefully. Need to lead healthy image life, make sure there are no infections or cure existing abnormalities.

Of course, it will not be possible to completely minimize the risks of the disease. There is only one piece of advice here: undergo all mandatory screenings and other examinations indicated during pregnancy on time.

Causes and mechanism of development of heart defects in the fetus

The heart is one of the first of all embryonic organs to form. Already in the first trimester it begins its work. Heart defects during pregnancy in the fetus are most often the result of hereditary factors, diseases of the woman, and retribution for the harmful lifestyle of the expectant mother. Less commonly, the formation of congenital heart disease is associated with other anomalies of embryonic development, for example, Down syndrome.

The risk of fetal congenital heart disease is increased in the following women:

suffered miscarriages, stillbirths;
over 35 years of age;
smoked during pregnancy;
living in areas with unfavorable ecology;
recovered from early stages pregnancy with rubella;
who used aspirin, sulfa drugs, antibiotics during pregnancy;
having a strong family history of heart defects.

Congenital heart disease is a defect in the structure of the heart. According to statistics, ten children out of a thousand will have a diagnosis of congenital heart disease in their medical records. And their number will grow, mainly due to increased availability and efficiency diagnostic techniques. Now the diagnosis of congenital heart disease can be made without waiting for the birth of the baby, using standard analytical systems on different terms intrauterine development.

Heart defects are distinguished by a variety of semiotics. Cardiologists divide them into “pale” and “blue”. The former are characterized by pale skin. These mainly include cardiac septal defects. With “blue”, the skin acquires a bluish tint. This is due to the fact that there is not enough oxygen in the blood. The “blue” type of defects includes more severe conditions: Fallot’s disease, transposition of the great vessels and others.

Combined defects include pathologies of the heart valves. They are caused by underdevelopment of the valves, as well as by their gluing, usually due to a viral infection suffered by the mother during pregnancy.

If on any of these important days for the development of the embryo the pregnant body faces a threat, consequences in the form of the formation of a defect in the cardiovascular system are quite possible.

As a rule, future parents learn about many heart defects at the first screening, that is, starting from the 12th week of pregnancy. If the anomaly is too severe, after a series of clarifying examinations, the mother will be asked to terminate the pregnancy. If the congenital heart disease of the unborn child is compatible with life, parents will have time to prepare for the inevitable heart surgery after birth.

In some regions of Russia, intrauterine heart surgeries are already being carried out, allowing the baby to be born completely healthy.

Clinical manifestations of heart pathology in the fetus during pregnancy

As a rule, pregnancy with a fetus with congenital heart disease for a woman is not much different from the typical version. The diagnosis becomes obvious only when performing an ultrasound of the fetus and its heart, Doppler sonography or CTG.

A fetus with congenital heart disease usually suffers from hypoxia and has developmental delays. It is possible for a pregnant woman to be prescribed medications that facilitate the functioning of the fetal heart. But, as a rule, we are not talking about full compensation for the condition.

The main task of a mother carrying a child with a heart defect is to maximize the gestational age in the dynamics of the fetal condition.

Diagnosis and detailing of the fetal condition

The main indicator of normal fetal development is its heart rate.

strokes before the eighth week of pregnancy;
until the end of the first trimester;
before giving birth.

Malformations of the fetal cardiovascular system are indicated by:

bradycardia or tachycardia;
different time intervals between impacts;
muffled sounds of heartbeat are a sign of oxygen starvation of the fetus.

A fetal heart defect on ultrasound becomes obvious when a defect in the organ chambers is visualized. The heart rate of the unborn child can be calculated already in the first trimester of pregnancy during a routine examination using an obstetric stethoscope. More full information CTG will give information about the functioning of the fetal heart, which is prescribed after 32 weeks of pregnancy. Having assessed its results, obstetricians determine the parameters of the baby’s condition.

The main conclusions of the analysis of fetal condition indicators:

below 1.0 is normal;
0.8-1.0 - borderline state;
up to 2.0 - primary deviations. Repeated CTG within a week is indicated;
up to 3.0 - severe deviations. Inpatient treatment is indicated;
more than 3.0 - critical condition of the fetus, indicating severe suffering.

These are examination methods that are accessible to both the patient and the doctor. They do not require special preparation and do not take much time.

But Doppler echocardiography is considered the leader in the study of hemodynamic processes in the heart and blood vessels of the fetus. This method evaluates three main indicators - the direction, speed and nature of blood flow. The procedure is as follows: an ultrasound sensor is installed on the pregnant woman’s stomach. A color image is transmitted to the screen. Red indicates the flow of blood, which moves towards the sensor. Blue color indicates the volume of blood flowing in the opposite direction. The maximum intensity of a particular color indicates increased hemodynamics.

ECHO-CG provides extremely valuable information about the heart and the fetus itself. The test can be prescribed at any stage of pregnancy, but, as a rule, it is performed starting from the 12th week after receiving warning indications from the first screening.

This study will determine:

direction and speed of blood flow in the vessels;
patency of the bloodstream;
the ratio of the volumes of blood entering and exiting the fetal heart;

Studies conducted earlier than this period will not be sufficiently objective due to the small size of the fetal heart. Towards the end of pregnancy, ECHO-CG of the fetus is rarely used due to the large volume of the abdomen, which makes visualization of the organ difficult.

A pediatric cardiologist and cardiac surgeon are involved in resolving issues related to the results of examination of a fetus with congenital heart disease.

Tactics for managing a pregnant woman with suspected fetal heart disease

Obstetric tactics for managing a pregnant woman who is carrying a fetus with congenital heart disease is to raise the question of amnio- or cordocentesis after a thorough echocardiographic examination. Their goal is to obtain material for conducting chromosome analysis. If congenital heart disease is detected in a non-viable fetus, the pregnant woman will be offered an abortion. The timing does not matter at all, especially if the heart defect is combined with genetic abnormalities of the fetus.

If congenital heart disease is compatible with life, then the pregnant woman is under intensive observation by obstetricians until the end of her term. After forty weeks, she will be asked to be hospitalized for delivery in a specialized perinatal center. As a rule, in case of congenital heart disease, delivery of the fetus by cesarean section is indicated.

After birth, the baby will be transferred for examination, treatment and possible surgery to the cardiology department of the children's hospital.

conclusions

Any fetal malformation detected during pregnancy is always a difficult problem both for the expectant mother and for the doctors providing for her pregnancy. Heart disease is no exception. Now there are many reliable methods that allow, in the early stages of pregnancy, to refute or confirm the diagnosis of congenital heart disease, assess the condition of the fetus, and make an assumption about its viability. Almost all of them are widely used and available to patients.

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Heart defect in the fetus in the womb

Heart disease is one of the most dangerous, and when it comes to children, the prognosis can be extremely disappointing. Find a similar disease on early stage development is not always possible, so the pathological process is severe and causes serious consequences. Carrying a child is often accompanied by certain difficulties; problems with the baby’s main organ are not uncommon. Heart defects in the fetus during pregnancy are considered fatal dangerous disease, but medicine can help such children.

general characteristics

The structure of the heart is unique, the organ consists of muscle tissue that constantly contracts to pump blood through the arteries of the body. Normal blood circulation creates all the conditions for the full functioning of all body systems. If this process fails, the delivery of oxygen and other nutrients to the organs is disrupted, causing various pathologies. The heart is divided into four chambers. The upper two sections are called atria, and the lower sections are called ventricles. Blood first flows into the atria, and then into the cavity of the ventricles, and only from there does it enter the heart valves, of which there are also four, and then into the great arteries.

Any congenital defect of a major organ is a serious problem arising as a result of disturbances in the intrauterine development of the fetus. The disease can manifest itself in children immediately after their birth, and sometimes symptoms are completely absent until a certain age of the child. The disease itself is an anatomical defect that occurs in the area of the main organ, its vessels, and the valve apparatus. Statistics show that heart defects during pregnancy are detected in the fetus in 7-8 cases out of a thousand births. No matter how sad it may sound, this pathology is the most common cause deaths in children.

Such ailments are very diverse; the prognosis of the disease and the treatment method depend on their type.

narrowing of the aorta;
anomaly of the development of the septum, interatrial and interventricular;
open type ductus arteriosus;
aortic stenosis;
stenosis of certain arteries, most often pulmonary;
structural changes in large main arteries.

Currently, medicine knows more than a thousand types of heart defects in a child and in the fetus in the womb. Depending on the form of such a disease, a change in shade is distinguished skin children at birth. If the baby has tatralogy of Fallot, fusion of the openings of the arteries of the lungs, incorrect position trunk of the pulmonary artery or the aorta extending from the organ, then the color of the baby’s skin, especially in the mouth, ears and body, will be bluish at birth. In addition, such manifestations can be observed and intensified when the baby is breastfeeding or crying heavily.

A white heart defect in the embryo means that the baby will be pale at birth. Further, in an older period, the tips of the fingers and toes of these patients may become cold. If pregnancy is accompanied by such a serious pathology as defects in the heart area, this is usually detected by a routine ultrasound - the doctor hears noises in the work of the main organ of the fetus. This disease may occur without the presence of symptoms, but when the child turns 10 years old, the disease will make itself known, preventing the little person from living normally.

Reasons for development

The formation of the embryo's heart occurs at 5-8 weeks of gestation, so it is important during this period to protect the expectant mother from various negative influences. If at this time of pregnancy there is any slightest malfunction in the body, this can affect the main organ of the child. Certain diseases that a woman suffered from during the entire period of waiting for the baby can provoke heart defects in the fetus, which will be visible on an ultrasound.

These diseases are very dangerous for any pregnant woman, and if such a disease nevertheless affects the expectant mother, doctors often recommend interrupting pregnancy. In addition, there are many more factors that can cause such abnormalities in the embryo.

Hereditary factor.
Chronic diseases.
Infectious diseases.
Influence medications.
The radiation is radioactive.
Bad habits.
Disorder of metabolic processes associated with hormones and other substances.
Wrong diet.

All these factors are related to the pregnant woman herself. In addition, fetal hypoxia also has negative impact to the embryo. Scientists have proposed a theory that chromosome defects also lead to heart defects in babies, as well as harmful environmental influences. Medications taken by expectant mothers for a long period of time can affect the fetal heart.

What medications can affect:

tranquilizers;
antibacterial drugs;
hormonal agents;
antiviral medications.

Many women are unable to become pregnant on their own and resort to in vitro fertilization. The process of preparing for this manipulation involves taking a large number of medications, hormonal or antiviral, which in the future negatively affects the baby’s health and can provoke disorders in the cardiovascular system.

The presence of infections such as ureaplasmosis, cytomegalovirus, herpes virus, leukoplasmosis or Coxsackie virus in expectant mothers affects the development of the fetus negatively, leading to a large number pathologies. They are the most dangerous factors that provoke heart defects in the baby. Diseases can be asymptomatic when patients are unaware of their existence in their bodies, which further worsens the situation. Identify such viral infections it is possible only with the help of special tests, and they cannot be treated - it is only possible to reduce their activity.

In addition to these diseases, there are many more types of conditions that have not been fully studied, and their effect on the body of the expectant mother and embryo is unknown. The Coxsackie virus is just such a disease; there are many types of it, and the symptoms are mild. The influence of such a disease often leads to termination of pregnancy and other deplorable facts.

If we talk specifically about defects, viruses provoke extremely severe disorders, this is due to the fact that such ailments affect the formation of the heart during an important period when the process of cell differentiation continues. This leads to complex defective changes in the structure of the organ. Taking as an example 8 pregnant women who did not treat such diseases, and 6 of them will give birth to children with anatomical disorders in the left parts of the heart, which will bear the greatest load in the future.

Diagnostics

The study of all aspects of pathology before the onset of childbirth is the main point in deciding the issue of treatment methods. The condition of the baby at birth depends entirely on the accuracy of diagnostic measures and the actions of doctors. Doctors decide what to do if the fetus has a heart defect during pregnancy.

ultrasound method for studying the heartbeat and organ structure;
echocardiography;
genetic karyotyping (very rare).

The doctor can accurately make such a diagnosis immediately after the woman undergoes an ultrasound. Thanks to the fact that this method has been improved, such a fruit defect can be detected at an early stage of gestation, within weeks. When the expectant mother skips this procedure for due date, it is necessary to carry it out at a later stage, weeks. It is at this time that all cardiac-type disorders are available to doctors. It is important that fetal heart defects on ultrasound are studied by an experienced doctor who can make a targeted diagnosis by studying the details of the pathology.

If such abnormalities are confirmed in the baby, there is no need to panic, this will only worsen the child’s health. The main thing is to carry out ultrasound examination in a timely manner for more later pregnancy, so that it becomes clear how the myocardium contracts and whether fluid accumulates in the pericardial area. Such abnormalities usually indicate intrauterine infection, but they can be eliminated with medications before birth.

When heart disorders are of organic origin, then diagnosing them is also not difficult, but it is necessary to treat them in a hospital setting, under the supervision of a cardiologist. Echocardiography is prescribed to pregnant patients already in the third trimester of pregnancy, within a week. This procedure allows doctors to understand at the time of delivery what the anatomical features of the defect are.

Some types of pathologies arise due to chromosomal mutations, then genetic karyotyping must be performed. This procedure is invasive and the purpose of such research is to study fetal cells, but doctors resort to it only in extremely rare cases. More than 50% of all severe defects in babies in the womb occur together with Down's disease. This situation often ends in termination of pregnancy; the doctor will advise the woman to have an abortion. These babies are born in a serious condition; they will not be able to endure surgery, and it is also dangerous to administer anesthesia to them.

Treatment

Despite the severity of the defect, the child needs to undergo surgery. This is the only way to correct the defect. If the baby was born with extremely serious heart problems, then surgical intervention is performed in the first hours or days of his life. Since the main organ is constantly growing, along with the whole body, some structural abnormalities of the heart can be eliminated only after the little patient reaches puberty. If it is not possible to postpone the operation, then it is performed immediately, and after several years they do another one. Sometimes, if the defect is diagnosed as a violation of the interventricular septum, then after a certain period the septum will close on its own.

After surgery, the child is usually prescribed antibacterial agents, which is necessary for prevention. Such events are due to the fact that infectious pathologies capable of affecting the heart, the inner layer of the organ, valves and endocardium. Until the treatment is completed completely, active games are contraindicated for children so that increased stress does not occur. negative influence on the heart valves.

Prevention

Pregnancy planning is one of the most reliable methods of prevention. Today, few people prepare for this important step; usually a child is born by accident. Many parents rely on their health and believe that if they feel good, then there will be no problems with bearing the baby.

Due to the fact that the formation of the heart occurs in the first trimester of pregnancy, namely at 5-8 weeks, then Special attention needs to be focused specifically on this period.

Often women do not yet know that they are expecting a child. The fifth week of the term is especially important, since during this period the processes of separation of all departments of the organ occur. Any, even the slightest, violation of this program can lead to defects in heart formation. Even one can influence in this way taken pill or drinking a glass of alcohol.

If pregnancy is planned, then certain recommendations should be followed.

Nutrition should be healthy and correct, include fruits, vegetables, lean meat, dairy products. It is necessary to remove fatty and fried foods from the diet, as well as smoked foods and fast food.
Daily walks along the street, lasting at least 3 hours.
Regular visit medical institutions for a routine examination.
Avoid excessive physical and emotional stress.
Complete refusal bad habits in the form of drinking alcohol and smoking.

A woman who wants to give birth to a healthy baby is simply obliged to monitor her lifestyle and protect herself from any harmful effects.

Heart defects in the fetus are often detected during pregnancy, but there are techniques to eliminate this defect. However, we should not forget that cases of death are also observed, even after timely surgical intervention. If a similar pathology is discovered while carrying a child, then you should take this issue seriously and follow all the prescriptions and recommendations of the treating doctor. Treatment during pregnancy and the correct actions of doctors immediately after birth allow us to hope for a favorable outcome and complete recovery of the baby. In most cases, such children grow up healthy and are able to live normal life without limiting yourself in anything.

Throughout pregnancy, specialists carefully monitor the frequency of contraction of the fetal heart muscle. And this is natural, because normal development heart and cardiovascular system is an indicator of vitality and proper growth. The heartbeat acts as the most important evidence of favorable conditions for the development of the embryo. The frequency and nature of heart contractions allow specialists to monitor the condition of the fetus during pregnancy and directly during the birth process.

The formation of the heart occurs progressively. Initially similar to a hollow tube, by the ninth week it becomes a full-fledged organ with ventricles and atria. However, the fetal heart has peculiar features that are not found in an adult. The presence of an oval window located between the atria of the duct connecting the aorta and pulmonary artery is due to the fetus’s dependence on the mother’s respiratory system, its inability to independent breathing. Nature took reasonable care of man. Thus, it ensured normal blood supply with oxygen and essential vital substances. internal organs embryo. After the baby is born, the ductus arteriosus no longer exists, and the oval window closes.

Studies determining fetal heart development

Ultrasound examination helps to accurately determine the time when the fetus begins to have a heartbeat. As a rule, this occurs after the third week of pregnancy. At the same time, internal organs begin to form. At five weeks, when the first perceptible heartbeats appear, a beating becomes audible little heart embryo.

An adequate level of the hormone hCG (human chorionic gonadotropin), which appears in a woman’s body already 5-6 days after conception, is responsible for the normal development of pregnancy. In the first trimester hCG level increases sharply, reaching a limit by the tenth week .

Rapid increase and concentration in urine and blood beta hormone hCG is an ideal indicator of pregnancy. In the second half of the term, the level of hCG in the blood decreases slightly, remaining unchanged until the end of the term.

What methods allow you to diagnose heartbeat?

Auscultation - using an obstetric stethoscope, you can hear a small heart beating;
Ultrasound diagnostics (ultrasound);
echocardiogram;
cardiotogram.

Today, ultrasound is used effectively and widely to monitor the functioning of the heart muscle. It is this that shows the most accurate results already in the earliest stages of pregnancy.

There are two types of diagnostics using ultrasound in pregnant women:

transvaginal, involves the introduction of a special device - an indicator into the vagina, carried out starting from the fifth week of fetal development, when a perceptible heartbeat appears;
transabdominal, carried out in the seventh week, using a sensor - indicator located on the woman’s stomach.

No longer five weeks into pregnancy, with the help of ultrasound, a fertilized egg begins to be visualized in the woman’s uterus. What should be the ideal blood hCG level? At the initial stage, it varies from 1000 to 1500 IU/l. If the hCG level is lower, there may be problems with visualizing the ovum even with the help of transvaginal diagnosis. Transabdominal examination establishes the presence of an amniotic sac only if the hCG level is 3000 - 5000 IU/l. Using transvaginal ultrasound, the embryonic structure is visualized in the fertilized egg at six weeks of pregnancy. The beta hCG level should be 7200 IU/l.

Normal heart rate

The frequency of contractions of the heart muscle is an indicator of positive fetal development. There are generally accepted indicators that help determine a favorable degree of pregnancy:

a heart muscle contraction frequency of 130 beats per minute is the norm in the early stages;
170-190 beats per minute - the fetal heart should work at this rhythm in the tenth week of development;
starting from the thirteenth week, the heart rate decreases to 140-160 beats per minute and remains unchanged until birth.

When the fetus does not have a heartbeat, the hCG level must be examined. Low levels of the presence of this hormone in a woman’s body indicate that pregnancy is not developing. “Frozen pregnancy” - such a disappointing diagnosis is made by specialists when hCG rapidly decreases against the background of an absent fetal heartbeat. Intrauterine death recorded at 18-28 weeks, when the contraction of the heart is not heard. In this case, immediate termination of pregnancy is required. Abortion at a later stage can lead to an inflammatory process, complications that pose a threat to the woman’s life, and can also make themselves felt during the next pregnancy.

Heart originally has a paired bookmark, it appears in humans at that stage of development when the embryo is still spread out in the plane. At this time, the heart is a paired large vessel. In animals with less yolk content in the egg (amphibians and lower fish), the heart is formed from the very beginning in the form of a single endothelial tube.

However, in cases where embryo develops from a flat embryonic shield, the anlage of the heart due to the large amount of yolk in the egg (in higher fish, reptiles and, finally, in mammals) must be double, its fusion into a single heart tube occurs secondarily.

basis human hearts is the area of the so-called cardiogenic plate, which is already observed in embryos prostrate in the plane under the cranial, cephalic end of the embryo body in the condensed mesoderm of the splanchnopleura. First, several slits appear dorsal to this plate. irregular shape, which over time merge into a continuous single cavity of the future pericardial (pericardial) cavity.

It is generally the first part of the foundation embryonic body cavity. The area of the cardiogenic plate and the anlage of the pericardial cavity, located on both sides of the body, after the separation of the cranial end of the embryo from the environment, moves, as already described above, to its ventral side, then located ventral to the head intestine.

At the same time, the bookmark of the heart turns in such a way that its sections, which initially lie cranially, turn out to be located caudally, and the anlage of the pericardial cavity moves ventral to the anlage of the heart.

The first laying of the heart tube is a collection of condensed mesenchymal cells lying in the region of the cardiogenic plate. These cells on both sides of the body are distributed into two longitudinally extending stripes, in which gaps subsequently appear; thus, two endothelial tubes running longitudinally and laterally appear, located on both sides of the head intestine in two folds of mesenchyme, protruding into the anlage of the pericardial cavity.

As rapprochement both anlages between each other, both tubes gradually merge with each other along the midline, forming a single heart tube, and the fusion first occurs in a more cephalad region. At the same time, their mesenchymal membrane also merges into a single, so-called myoepicardial tube, which is the rudiment for the heart muscles and epicardium. At first, the caudal parts of the heart tube are not yet connected.

They are double and present constitute the anlages of both future atria. During the process of fusion, both anlages of the pericardial cavity merge into a single pericardial cavity. The primary heart tube in this cavity is attached to its back wall through a double fold of mesenchyme, which is called the cardiac mesentery - mesocardium. Finally, the caudal sections of the heart tube also unite, resulting in a single, generally still straight heart tube.

This stage of development is formed during fourth embryonic week. From the very beginning, the anlage of the ventral cardiac mesentery is absent, and the dorsal cardiac mesentery subsequently disappears almost completely.

Educational video of heart development (embryogenesis)

Table of contents of the topic “Development of the musculoskeletal and cardiovascular systems of the fetus”: