Why and how is CTG done during pregnancy? Interpretation of the fetal cardiotocogram (CTG) Examination of the fetal CTG.

Monitoring the condition of the fetus is an important goal of examining a pregnant woman. It can be carried out using different methods. Cardiotocography is the most common, painless and accessible method of instrumental monitoring of the condition.

Cardiotocography is a technique for assessing the condition of a fetus developing in the womb, which consists of analyzing changes in its heart rate at rest, during movements, and also in response to external factors.

Equipment for this study - cardiotocographs - are available in all antenatal clinics and maternity hospitals.

The methodology of this study is based on the well-known Doppler effect. The hardware sensor creates special ultrasonic waves that are directed into the body and reflected from the surface of media with different sound conductivity, after which they are recorded again by it. When the interface between media shifts, for example, when moving, the frequency of the created and received ultrasonic wave becomes different. The time interval between each contraction of the heart is the heart rate (HR).

Target conducting CTG- timely detection of deviations in the functional state of the fetus, which allows the doctor, if any, to select the necessary therapy, as well as choose the appropriate timing and method of delivery.

Preparation

No special preparation is needed for this study.. But to obtain reliable results during the study, the woman must be relaxed and in a comfortable position, without moving. Therefore, before the procedure, you should go to the toilet in advance.

It is recommended to eat approximately 2 hours before the test and should not be done on an empty stomach. In agreement with the doctor, small snacks with something sweet are allowed during the procedure if the baby is in the sleep phase in order to activate it. To add to this, you can purchase sweet foods in advance.

You should not take painkillers and sedatives 10-12 hours before the examination.

Methodology

During the examination, the expectant mother takes a position on the couch, lying on the right or left side of the body or half-sitting, leaning on a pillow. Special meters are fixed on her stomach - gel is applied to one and fixed in the place where the fetal heartbeat is best felt, the other sensor, which registers excitations and contractions, is placed in the area of the projection of the right angle or the fundus of the uterus. The patient independently notes the periods of fetal movement using a button to register fetal movements.

Monitoring is carried out for at least half an hour to obtain the most accurate information about well-being. This duration of the study is explained by the child’s frequent alternation of sleep and wakefulness phases.

Decoding

Unlike many other research methods decoding CTG at 32, 33, 34, 36, 37, 38, 39 and 40 weeks does not have any significant age-related nuances. There is a slight trend towards a decrease in the average fetal heart rate from 32, 33, 34 to 38 weeks.

Fetal movements on a cardiotocogram

One of the components of CTG recording is currently actography - recording fetal movements in the form of a graph. There are two ways to assess a child's movements. The mother can independently count the movements of the fetus that she feels. Or many modern devices are capable of recording movements themselves using a sensor. The second registration method is considered more reliable. In this case, the movements appear on the actography graph as high peaks.

The fetus moves almost constantly, except during periods of sleep. According to CTG data, during 32.34, as well as 35-40 weeks of a normally developing pregnancy, the motor activity of the fetus generally increases. At 34 weeks, there is an average of 50–70 movements per hour. After 34 weeks, an increase in the number of movements is recorded. Thus, from 60 to 80 movements per hour are recorded. The average duration of episodes of movements is 3-4 seconds. Gradually, as the fetus grows, it becomes more crowded in the uterine cavity, so closer to it it becomes calmer.

Contractions on a cardiotocogram

In addition to the fetal heart rate and its movements, CTG can record contractile movements of the uterus, that is, contractions. The recording of contractions on CTG is called a tocogram and is also depicted as a graph. Normally, the uterus reacts to the movements of the fetus in it with its contractions (contractions). At the same time, a decrease in the child’s heart rate is recorded on CTG in response to uterine spasms. Contractions are the main sign of impending labor. Based on the tocogram, the doctor can determine the force of contraction of the muscular layer of the uterus and distinguish false contractions from true ones.

Based on all of the above, it is clear that CTG is a very important examination of the condition of the developing fetus in the womb, which allows you to obtain information about the state of the heart rhythm, movements and even evaluate contractions. Any deviations on CTG require a thorough cumulative analysis by a competent specialist in order to take the necessary measures that can save the life of the little man. All these properties make CTG an indispensable type of examination.

What is CTG in pregnant women? Cardiotocography (CTG) is a method of functional study of the state of the fetus in the womb of a pregnant woman, which is based on a sequential recording of the child’s heart rate and its changes in accordance with the contractile movements of the uterus, the influence of environmental factors and the activity of the baby himself.

This recording of the heartbeat is carried out within 15 minutes and can be carried out both in a calm state of a woman outside the labor process, and during labor and childbirth. This feature makes CTG quite effective and useful method to resolve the issue of delivery tactics.

What does CTG show? First of all, this type of research is carried out to obtain information about fetal heart rate, the regularity of his cardiac activity, as well as active movements.

In addition, the information content of CTG is very important in determining the frequency of contractions of the smooth muscle cells of the uterus and the child’s reaction to these contractions.

Cardiotocography is effective method research to exclude or timely determination of pathological conditions of mother and child posing a threat to the course of pregnancy and to the future health of the newborn baby, such as intrauterine infection of the fetus, oligohydramnios, congenital abnormal development of the cardiovascular system, fetoplacental insufficiency and the threat of labor starting earlier than planned.

Main indications for CTG

A woman with Rh-negative blood is at risk of developing hemolytic disease of the newborn.
A history of premature labor, miscarriages and abortions.
Feelings of decreased fetal movements in the pregnant woman herself.
Complications during pregnancy (multiple fetuses, polyhydramnios, oligohydramnios, fever or low-grade temperature in a pregnant woman, incorrect presentation of the baby, post-term pregnancy).
Disorders in the child that were previously found with (developmental delay, disorders in amniotic fluid ah, decreased activity, pathological changes in blood circulation in the placenta, the baby’s size is too large or small, inappropriate for the month of pregnancy).
Endocrine and systemic diseases in pregnant women (types 1 and 2, diseases of the cardiovascular system).

This method of studying the condition of a child during his intrauterine life is safe, since the sensor reproduces an ultrasonic wave of weak strength, does not cause negative effects on the baby.

At what stage is fetal CTG done?

The use of cardiotocography can begin with approximately , but high-quality and informative recording of the above parameters that characterize the state of the child in the womb is only possible with .

This is due to the development of periodically alternating cycles in the baby, when he is active or calm in motor terms. The baby is most active in the period from 9 to 14 pm, as well as from 19 to 24 pm.

How to prepare for CTG during pregnancy? CTG is contraindicated after meals, since elevated levels can significantly affect the fetus, increasing its movements and reaction to external environmental stimuli.

How to do fetal CTG during pregnancy

Cardiotocography is performed using specialized sensor, which has ultrasonic effect and is based on the effect.

This device is tightly secured to the front of the pregnant woman's abdomen, where the baby's heart sounds are most clearly heard. Such an area can be preliminarily determined without any problems using an obstetric stethoscope.

The sensor, producing a signal in the form of an ultrasonic wave, directs it towards the baby's heart in the womb. The wave is reflected from the heart, which is perceived again by the same sensor in the end. The received information is converted into values fetal heart rate per minute. The research results are reproduced sound, light and graphically on tape.

If the pregnancy is normal, CTG is performed no more than once a week. In case of a complicated pregnancy, but with good results from previous methods of fetal examination, this procedure is performed with a pause of an average of 6 days.

If it has developed child hypoxia in the womb, CTG is indicated for daily or every other day for constant dynamic monitoring of the child’s condition and timely adoption of measures for emergency childbirth.

Interpretation of fetal CTG results during pregnancy

The results of the cardiotocography analysis are assessed specialist in a number of indicators, which include the basal rhythm, variability, acceleration, deceleration and, finally, the activity of the baby’s movements in the womb. All this is depicted at the end of the manipulation on paper in the form of graphs of various shapes.

How to decipher CTG? You should not try to decipher your CTG yourself, since you, not being a doctor, will make a mistake when deciphering the fetal cardiotocography in calculating points based on the results, which, of course, can harm the child.

Basal rhythm is the average value of the fetal heart rate. Normally, the basal rhythm reaches from 110 to 160 heart beats per minute when the baby and pregnant woman are calm. When the child moves, the frequency of contractions increases to values ranging from 140 to 190 beats.

All normal values of the basal rhythm indicate absence of hypoxic condition baby's body. And the increase, as well as the decrease, are a clear sign of fetal hypoxia, which, first of all, is detrimental to its nervous system, although it is not yet fully developed.

Variability(in other words, amplitude) - a change in the value of the heart rate frequency and its amplitude relative to the obtained values of the basal rhythm of the baby’s heart.
Outside of pathology, the heart rate of a child in the womb should not be constantly the same and monotonous, which is clearly visualized by the continuous change of numerical values on the monitor during CTG. Normal changes in the relevant parameters should range from 5 to 25 beats per minute.

An increase in amplitude may indicate the same fetal hypoxia or, which is undoubtedly a pathology. Reduced amplitude values may be normal if the baby is in a calm state at the time of CTG. In order to “wake up” the baby, the mother can simply eat some sweetness.

Acceleration(acceleration) - an increase in the number of heart beats compared to the level of the basal heart rate. The magnitude of acceleration is expressed on the cardiotocogram in the form of teeth; normally it is at least 2-3 times within 15 minutes. It is permissible to increase the number of repetitions up to 4 times per half hour. What is pathological is their complete absence during the specified time period.

Deceleration(decrease) – a decrease in heart rate values in comparison with the level of basal heart rate. The magnitude of deceleration is expressed in the form of dips (“negative” teeth). Normally, such manifestations on the graph should not be present or be insignificant in depth, duration and occurrence.

The deterioration of the baby's condition in the womb can be confirmed by the occurrence of decelerations after 20 minutes of examination. Also a bad result is their repetition and different appearance throughout the entire chart. All this may indicate decompensated fetal stress.

Overall transcript norms of CTG results the fruit looks like this:

Basal rate – 120-159 per minute at rest.
Variability from 10 to 25 beats per minute.
2 or more accelerations within 10 minutes.
No decelerations.

Pathological CTG as follows:

Basal rhythm – less than 90 and more than 180 per minute.
Variability less than 5 beats per minute.
Absence or small number of accelerations.
Availability different types decelerations.

Fisher ten scale

The results of cardiotocography are assessed by specialists on a ten-point Fisher scale, which is based on assigning points from 0 to 2 to each of the above indicators. These scores are summed up, and a general conclusion is made about the information content of CTG and the presence of pathological changes in the fetus. The so-called "indicator of fetal condition"(PSP).

If total points CTG compiled from 1 to 5, then the baby’s condition in the womb is poor, he experiences hypoxia (lack of air).
What does it mean if the sum of CTG points is 6-7 ? The child shows initial signs of developing oxygen starvation.
What does it mean if the sum of CTG points is from 8 to 10? This indicates the norm and good condition baby.

With a PSP of 1-5 points, immediate delivery is indicated; with a PSP of 6-7 points, repeat CTG is indicated; with a PSP of 8-10 points, continued periodic monitoring of the pregnant woman and fetus using this research method.

How can pregnancy duration affect CTG readings?

If CTG is performed earlier than 29-32 weeks of pregnancy, it can become uninformative and meaningless, since it is by this period that the fetus develops a sleep-wake pattern, and previously it manifests itself only by calmness in the mother’s belly.

Depending on the week, the indicators are approximately the same, but the shorter the week, the higher the variability (amplitude).

The fact that the doctor did not like the results of cardiotocography does not mean a final determination of fetal hypoxia and pathology in principle. There are cases when young doctors without sufficient work experience incorrectly interpreted the information contained in the received graph, although everything was completely normal for the baby and his mother.

Therefore, you should not rush and immediately panic when you get a bad result. But you shouldn’t relax, as this may actually indicate a real pathology that requires immediate treatment and action on the part of medical professionals.

Most likely, if the results are alarmingly abnormal, the doctor will ask you to go to hospital in maternity hospital, where they will conduct regular CTG and will be able to quickly react in a dangerous situation.

How contractions appear on CTG

This study is required indicates the presence of contractions, since normally the uterus should react to the active motor activity of the baby with its spasms. In addition, the uterus has the ability to spontaneously contract. On CTG, in response to contractions, a decrease in the number of baby’s heartbeats and deceleration will be visible, which occurs in rare cases.

The second curve (hysterogram) reflects the increase in the force of contraction of the myometrium (muscular layer of the uterus) during contractions. The higher it is, the stronger the contractions. Some women in labor do not feel contractions; CTG helps determine their strength and frequency.

What is the Fetal Reactivity Index?

This indicator tells the specialist about the state of the fetus’s nervous system reactivity to external influences, which, first of all, affects the state of the cardiovascular system.

Calculation is carried out using a point system and further interpreted:

0 points means an absolute lack of reactivity in the baby.
1 point means severe disturbances in the body's reactivity.
2 points mean severe disturbances in the baby’s reactivity.
3 points indicate a moderate degree of impairment in reactivity.
4 points indicate the initial stage of the pathology of the child’s reactivity.
5 points means normal reactivity in the fetus.

What is a non-stress test?

This type of research into the condition of the baby in the womb is test to determine cardiac activity according to the baby's movements.

A good result is a negative non-stress test (the presence of 2-3 increases in the number of heart contractions by about 15 beats per minute for 15-20 seconds). In the case of a positive or no result at all, we can conclude that the baby is in a hypoxic state, which, in fact, may be a false phenomenon if at the time of the study the fetus was calm and sleeping. In this case, it is recommended to repeat the non-stress test.

Cardiotocography is one of the most precise methods determining baby hypoxia in the womb of a pregnant woman, which is very valuable for its timely diagnosis and taking measures to eliminate it. In the presence of hypoxia, CTG shows the following changes:

Decreased or complete deficiency of fetal heartbeats.
Increased heart rate when the fetus moves or the uterus contracts involuntarily.

Erroneous assessment of CTG results

Errors when interpreting information obtained using cardiotocography are certainly possible. For example, in case of hypoxia, but despite the fact that the baby’s tissues have already managed to adapt to it, CTG is not able to show this pathological condition. The same can happen if there is a sufficient amount of oxygen in the bloodstream, but the tissues cannot adequately accept and use it, which indicates actual fetal hypoxia.

The presence of errors obliges specialists to evaluate the results of CTG only in combination with the results of other studies carried out on a pregnant woman, and then make a final diagnosis.

Video about fetal cardiotocography (CTG)

We invite you to watch a video about fetal CTG. An obstetrician-gynecologist will tell you how and why this examination is carried out, how its results are evaluated, what normal indicators CTG.

Any pregnant woman will sooner or later undergo a CTG procedure; some of the readers have already encountered this study. That's why tell us about your impressions from cardiotocography, how its results were deciphered for you, and what gave you this painless manipulation. Don’t forget to leave feedback and ask questions about CTG, the answers to which most concern you or are still unclear.

It is impossible to determine the condition of the fetus during intrauterine development by external signs. If you refer only to motor activity, you can miss the alarming symptoms that are observed during intrauterine suffering. In times of lack of technical devices, obstetricians relied on the heartbeat. In modern medicine, fetal cardiotocography is used.

What is the technique?

Fetal CTG is literally explained as recording heart rate simultaneously with uterine activity. Special fetal monitors are used for registration. Their work is based on the Doppler principle. During the study, the intervals between cycles of the child’s cardiac activity are recorded. Strain gauges measure the force of uterine contraction. These indicators are recorded on paper tape in the form of a curve. Combining the patterns of two lines in time allows you to analyze the condition of the fetus. The curve of uterine contractions also reflects its mobility.

There are two ways to conduct research:

Outer.
Interior.

The external method is used in the third trimester and during childbirth. The sensor is applied to the anterior abdominal wall. The woman is in a lying position. As long as the belly is not too big, she can lie on her back. At the time of birth, in order to avoid pressure on the inferior vena cava, the pregnant woman is on her left side or in a semi-sitting position.

There are two sensors located on the stomach. The first one shows the heartbeat. To improve transmission, a gel is applied to the location. The point of application is determined by the position and presentation of the fetus. For this purpose, external obstetric techniques are used.

By the time of birth, most babies turn head down. Based on the results of palpating small parts of the body, they decide in which direction the back is turned. The sensor is placed on that side. Usually this is the right or left side at the level of the navel. When readings are recorded separately for each child.

The second sensor records the activity of the uterus. It is applied to the right uterine angle. It is from here that a wave of contractions begins, which spreads to the entire organ.

The patient is given another sensor. With its help, she herself registers the moments of the child’s movements. When you click on the button, a corresponding mark appears in the ribbon.

How long the recording lasts depends on individual characteristics. Usually this period is from 20 to 40 minutes. Interpretation of CTG results requires at least 20 minutes of recorded basal rhythm, in which at least 2 episodes of movement of 15 seconds or more will be noted. The number of heart contractions should increase.

Fetal monitor Bionet FC 1400 for determining the fetal heart rate of the fetus

The duration of the recording depends on the child's sleep and wake periods. In the mother's womb he can sleep for up to 30 minutes.

Internal CTG is performed only during labor. This technique is not as popular as external research. To carry it out, a spiral-shaped electrode is used, which is applied to the baby’s head through the vagina. An intra-amnial electrode is inserted to record uterine contractions. To carry out diagnostics, certain conditions must be met:

leaked amniotic fluid;
The cervix is dilated by 2 cm.

This technique has not found widespread use. During childbirth, it is more convenient to use the external recording method.

Types of functional test studies

A simple CTG recording without the use of various stimuli is called a non-stress test. But in some situations it is necessary to create conditions that resemble the birth process in order to find out how the physiology of the fetus will change during this period, and whether the load will be great for it during childbirth. A stress test was developed for these purposes.

Functional tests are used as stress, which become a model of childbirth. This following types test:

Oxytocin – a small amount of oxytocin is injected intravenously, which causes uterine contractions. CTG shows how the child’s body will behave under these conditions.
Mammary is similar in principle to the first type. When nipples are irritated, oxytocin is released.

Functional tests that affect the fetus are also used:

Acoustic test - the effect of a sound stimulus can increase his heartbeat.
The atropine test is performed by injecting atropine into a vein. A large number of complications and contraindications have led to the fact that this technique is not used.
Palpation - through the abdominal wall, the midwife tries to displace the pelvic end or head of the fetus. This also leads to increased heart rate.

Nowadays, stress tests are rarely performed because they are associated with high risk. With a high-quality CTG recorded, the doctor has enough data to understand what condition the child is in.

In what cases is research informative?

Medical protocols precisely determine at what stage of pregnancy fetal CTG is performed. They are based on the physiology of the child. Mandatory research is carried out from 32 weeks. In most cases, the doctor recommends performing a CTG before each appointment of a pregnant woman. But results can be obtained as early as 26 weeks. In some cases, according to indications, it is possible to carry out manipulation from 27 weeks.

To ensure that fetal indicators can be interpreted, the optimal hours for testing have been determined. This is the time of increased child activity: from 9.00 to 14.00, and from 19.00 to 24.00.

The following conditions distort CTG results:

hunger, in no case should manipulation be carried out on an empty stomach;
a large meal, the optimal time to choose is 1.5-2 hours after eating;
administration of glucose;
use of sedatives, magnesia;
stressful situations;
condition after physical activity of the mother;
smoking and drinking alcohol.

For example, the result will be incorrectly interpreted if the mother climbed the stairs to the 2-3 floor and immediately lay down under the CTG machine.

Diagnosis is difficult in overweight women. A thick layer of fat on the anterior abdominal wall does not allow the sensor to recognize the baby's heartbeat.

Sometimes, if the sensor is applied incorrectly, the device shows a heartbeat of 65-80 beats per minute. Don’t be alarmed, this is the mother’s own rhythm being recorded, and the sensor receives it from the pulsation of the aorta.

During childbirth, the use of CTG is mandatory. This allows you to monitor the condition of the fetus, assess how contractions are increasing or whether they are subsiding. Knowledge about uterine contractions is necessary for correct adjustment of labor. Insufficient contractions are the need to stimulate labor so that they do not tire the woman even at the stage of cervical dilatation and do not turn into weakness of labor.

Preparing for CTG

The procedure is carried out in a antenatal clinic. No special preparation required. It is enough to follow simple rules:

Get enough sleep the night before the procedure. The mother's condition affects motor activity fetus
Have a light snack before leaving the house. You need to take into account the road to the clinic so as not to be too full or, conversely, hungry.
Upon arrival, you need to rest a little and sit to restore your heart rate.
The procedure takes about 30 minutes, so the pregnant woman needs to worry about going to the toilet in advance.
Smoking mothers need to abstain from the bad habit for 2 hours.

No other additional preparation measures are required.

Are there any contraindications?

The technique is non-invasive and does not affect the condition of the fetus or uterus. The harm of CTG can only appear when performing stressful functional tests. But at present, the level of technology and the qualifications of doctors make it possible to identify severe conditions without the use of special stimuli.

Basic concepts of CTG

Fetal cardiotocography

Indicators of normal fetal condition during CTG are assessed according to the following data:

heart rate;
basal rhythm - the magnitude of heart contractions that is observed in the period between contractions for 10 minutes;
basal rate variability - the height of changes in heart rate;
acceleration - a short acceleration of heart rate for 15 seconds or more or 15 heart beats;
deceleration – decrease in heart rate by 15 beats or for 15 seconds.

Each of the above concepts has its own norm. The basal rhythm should be in the range of 120-160 beats per minute. Fetal variability on CTG is 5-25 beats. If you look at the CTG tape, the main fluctuation of the heart rate line should be within these limits.

Accelerations are sudden increases in heart contractions. Must be present for 10 minutes; normally, 2 or more increases in heart rate are recorded.

Decelerations are a decrease in the number of heart contractions. Normally, they are absent or appear episodic, short-lived and shallow. A prolonged decrease in heart rate indicates pathological conditions.

Deciphering the result

To quickly assess the result of CTG and identify initial fetal abnormalities, a system has been developed in which scores are assigned for each indicator. The count is carried out in the number of heartbeats.

Scoring helps determine the CTG result:

8-10 indicates normal condition.
5-7 – initial signs of hypoxia. In such a situation, repeated research is necessary within 24 hours. If the result remains the same, additional examination is carried out. It includes an assessment of blood flow in the vessels of the placenta and uterus, ultrasound, and determination of a biophysical profile.
4 points or less – a serious condition that requires emergency hospitalization. In this case, the decision is made either to carry out intensive care or delivery.

The CTG assessment is carried out not only taking into account the assigned points. In many clinics, the installed devices independently calculate such a value as the fetal condition indicator (FSP). Its norm should be less than 1.0. If PSP is equal to one or slightly higher, then repeated cardiotocography is recommended.

PSP 1.05-2.0 indicates initial signs of deterioration. The woman is prescribed treatment, and after 5-7 days she is monitored by cardiotocography. An increase in PSP to 2.01-3.0 is an indication for hospitalization and serious treatment. If this indicator exceeds 3.01, emergency delivery is necessary.

The normal requirements for the test result differ depending on the stage of pregnancy. By the time of full-term pregnancy (from 38 weeks), all indicators should be within the specified norm. In an immature child at 36 weeks, minor deviations are allowed, but the number of points should not be less than 8; in the tape, there are sufficient numbers of both acceleration and deceleration. Low variability within 3-6 is allowed.

If there are no pronounced accelerations and decelerations in the cardiotocography recording, this cannot be called normal. A monotonous fetal heartbeat is observed, which indicates hypoxia. In some cases, this change in rhythm is observed while the child is sleeping. To make sure, the midwife or doctor tries to move the fetal head through the abdomen.

The ability of the nervous system to respond to stimuli is indicated by the fetal reactivity index. But this indicator is not used in isolation. To decipher it, Doppler data from the placenta and uterine vessels are used. When blood flow decreases, development can be judged.

The information received from the fetal sensor during labor greatly helps to correct its progress. There are situations when the fetus pinches the umbilical cord during a contraction. This is noted on the screen as a pronounced decrease in heart rate and its long recovery. In such a situation, the doctor decides not to administer oxytocin in order to increase uterine contractions. Sometimes it is even necessary to move the head slightly through the vagina to ensure normal blood flow.

In severe cases, the gynecologist can promptly notice a sharp decrease in rhythm after the next contraction, which does not recover during the rest period. If there is information that a woman had infectious diseases during pregnancy, and when the amniotic fluid was opened, it was meconium in nature, then an emergency decision may be made in the interests of the child.

Is CTG harmful to the fetus?

Non-stress tests do not pose any danger to either the baby or the course of pregnancy. This is a good help for the doctor, which helps him react correctly when the situation changes. You should not decipher it yourself: a non-specialist is not able to take into account all the available factors and draw the right conclusions.

One of the methods for determining the condition of the fetus during pregnancy is cardiotocography (CTG). It also allows you to evaluate the contractile activity of the uterus (contractions).

This study is carried out after 32 weeks of pregnancy, and also necessarily during childbirth.

To carry out the examination recorded synchronously uterine contractions and fetal heart rate for 15 or 30 minutes. When performing CTG, special sensors attached to the stomach future mother. The nurse first determines the best location to listen to the baby's heart sounds.

The following indicators are recorded and displayed on the monitor:

Basal fetal heart rate, its variability;
Acceleration - an increase in the fetal heart rate (HR) lasting at least 15 seconds by 15 or more beats per minute. They are usually caused by contractions of the uterus or the activity of the fetus while it is awake.
Decelerations. A decrease in the fetal heart rate during movements or contractions.

In combination with other research techniques, for example, ultrasound and Dopplerography, cardiotocography allows you to quickly and effectively determine pregnancy pathologies and correct them.

What disorders can be detected using CTG?

It is impossible to make a diagnosis using cardiotocography alone. But the CTG method allows us to suspect such deviations:

Fetal hypoxia.
Intrauterine infection.
Umbilical cord entanglement.
Disturbances in the functioning of the fetal heart.
Reduced or increased amount of water in the uterus.
Premature aging of the placenta.

When should a CTG be done?

It is not advisable to conduct an examination before 30 weeks. At such a time, the fetal heartbeat cannot be analyzed using sensors, and the child’s activity and rest cycle has not yet been formed and is chaotic.

Pregnant women usually undergo cardiotocography at 32-33 weeks, when the baby has developed a mode of rest and wakefulness, and the heartbeat can be heard well.

The doctor may prescribe repeated examinations if:

at the first CTG, malfunctions in the fetal heart were detected;
the woman’s previous pregnancies were unfavorable;
the child’s activity suddenly changes (no movements or the kicks are too intense);
the expectant mother suffered an acute illness or her life was under threat;
the woman has developed gestosis (a complication of pregnancy with edema, high blood pressure, and sometimes protein in the urine), or has infectious diseases;
a pregnant woman has bad habits;
The pregnancy period exceeds 42 weeks.

How to make a diagnosis correctly?

It is important to determine the optimal time to record. The expectant mother should be rested and not hungry. You should also rely on the baby’s activity mode - there is no point in conducting CTG when the baby is sleeping. You need to find a comfortable position for the woman - sitting on a chair with support on her back or lying on her side. It is also necessary to focus on the sensations of the pregnant woman - there shouldn't be any discomfort. A gel is applied to the sensor to improve the conductivity of impulses.

Only a doctor should interpret the results. There are many variants of norms and deviations from them, and it is difficult to subordinate them to a single system. We need a complete and objective picture. It also happens that CTG indicators according to conventional decoding methods correspond to the norm, but in combination with other factors they indicate violations.

At normal pregnancy available false entry, indicating pathology. Common reasons such a phenomenon:

recording while the child is sleeping;
obesity of the expectant mother (the large thickness of the abdominal wall prevents normal listening to the fetal heart rate);
lack of special gel on the sensor;
multiple pregnancy.

Types of devices and possible harm

All devices for CTG are divided into two groups. The first ones record the fetal heartbeat and contractions on tape. The result is not deciphered by the device. The tape is analyzed by a doctor using the Fisher scale. The second ones are not only write down, but also decipher the resulting curve. However, in this case, the doctor must analyze the protocol.

Some mothers notice that during the examination the child is very worried or, on the contrary, it calms down. This is probably due to the pressure of the sensor or the sound of the equipment that is heard by the baby. There have been no official studies that 100% prove or disprove the harm of CTG for a child. But it is worth understanding that the discomfort that the baby receives during the examination is not commensurate with the risk of missing dangerous pathological conditions if CTG is abandoned.

Norm of indicators

To evaluate CTG, the Fisher method is most often used. The following indicators are analyzed:

Basal rhythm. This is the average fetal heart rate over the entire period of the examination. The norm is 118-161 beats/min. An increase or decrease may indicate hypoxia.
Variability. This is the amplitude of the heartbeat. The heart rate numbers on the monitor change every second. Normal fluctuations are 5-25 beats up or down. Too large an amplitude indicates fetal pathology.
Frequency of movements. The normal value is more than 6 and less than 10 in 15 minutes.
Acceleration. We can talk about the well-being of the fetus if in 10 minutes the heartbeat increases at least 2 times for 30-60 seconds.
Decelerations. Normally, heart rate decreases by more than 60 seconds must not be. This condition may indicate hypoxia or another pathology.

The most common abnormalities on CTG protocols are monotonous and sinus rhythm. The first is observed when the fetus is sleeping or if there is a pathology associated with impaired oxygen supply. The condition of the fetus is similar to when a person is sick and becomes drowsy.

Sinus rhythm is observed when the child is constantly active. If a woman feels that the fetus is calm, but the CTG produces sinusoids, then we can talk about the serious condition of the baby.

Decoding the results

The doctor evaluates every sign value from 0 to 2 points. When an indicator deviates from the norm upward or downward, it is assigned 1 point. The normal value is estimated at 2 points. If there is a critical decrease or increase, 0 points are given. All points received are added up. The result is deciphered as follows:

0-4 points. An acute condition requiring additional diagnosis and intervention. A medical consultation must be held.
5-7 points. The fetus experiences oxygen starvation. Treatment is urgently required to improve blood flow in the mother-child system. Most often, an additional unscheduled ultrasound is prescribed.
8-10 points. A good indicator. The baby is fine.

Using modern CTG equipment, the result is recorded and printed at the end of the study. The protocol indicates how long the examination lasted and at what point all the criteria for normal fetal heart rate were met. Any device can record one session lasting no more than an hour. Settings are set depending on whether CTG is performed during pregnancy or directly during childbirth. You should not try to decipher the result yourself - there is a high risk of error.

average price

CTG is a routine examination during pregnancy, therefore, in antenatal clinics and maternity hospitals, it is carried out for free. But in some cases, a woman wants to make sure that everything is fine with the child and goes to a private medical center for unscheduled examinations.

Around the country, the price of cardiotocography varies depending on how popular the medical center is, as well as the quality of the equipment. The lowest cost for CTG by region is 300-400 rubles in singleton pregnancy. On average, the price varies from 500 to 1500 rubles. At multiple pregnancy the cost is higher - from 800 to 3000 rubles. If a woman is observed in a private clinic, then CHT, as a rule, is included in the total cost of pregnancy management.

The most joyful time in every woman's life is, of course, pregnancy. But at the same time, this is a responsible period. After all, every mother wants her baby to develop well in the most comfortable conditions. To do this, you have to constantly monitor your lifestyle, take various tests and be constantly examined. One of the most important diagnostic methods is CTG during pregnancy.

What it is?

Cardiotocography (CTG) is a way to assess the functional well-being of a baby in the womb. Makes it possible to record uterine contractions and the baby's heart rate.

At the same level as ultrasound and Doppler, CTG during pregnancy is currently considered an integral part of assessing the well-being of the fetus. Thanks to CTG, it is possible to detect any abnormalities and prescribe treatment. Or, if there is a deterioration in the condition of the fetus, an emergency delivery can be performed and thereby save the baby.

When is it done and how many times?

The first CTG during pregnancy is carried out in the third trimester of pregnancy, starting from the thirty-second week. If necessary, the attending physician sometimes has the right to prescribe it at the 28th week of pregnancy.

Subsequently, they are carried out once every ten days, if the patient’s health is excellent. In case any changes are noticed in the expectant mother, then medical worker has the right to prescribe auxiliary examinations.

This may occur if a woman:

chronic diseases;
risk of miscarriage;
the baby's activity is reduced;
the expected due date has passed.

Only in the third trimester will the baby be able to track his heart rate, since at this time a uniform sleep-wake schedule is established.

CTG during pregnancy: norm and interpretation

Cardiotocography still cannot establish the main diagnosis; the results are only auxiliary information about the child’s condition at certain periods of time. And you shouldn’t judge the child’s health by one cardiotocography; it needs to be done several times throughout pregnancy.

Only a doctor can determine whether there are deviations from the norm. The results of the study are displayed on a special tape on which curves in the form of teeth are depicted. With cardiotocography, the average heart rate is assessed, which is recorded on the tape with the abbreviation HR or BHR.

The normal value at rest will be from 110 to 160 beats per minute. When the baby begins to move, the beats also begin to increase to 130, and sometimes up to 190 beats.

The average height of deviations from the basal rhythm is examined; normally it should be from 5 to 25 beats per minute. In addition, a study of uterine activity (tocogram) is carried out; normally it should be no more than 15 percent of the baby’s heart rate for 30 seconds.

It can be deciphered using a ten-point system, where each indicator scores from 0 to two points. As a result, if the study scores from 9 to 12 points, then everything is fine with the baby, if from 6 to 8 points, then the fetus has hypoxia. In this condition, the procedure must be repeated.

If the score is less than five points, then this indicates severe fetal hypoxia, and prompt medical intervention is required. At this point, the medical professional decides to induce labor.

CTG result

Is it possible to refuse?

Modern cardiotocography devices provide many possibilities:

write down and take into account everything;
record the presence of existing uterine tone;
some make it possible to independently decipher the information and ultimately draw a conclusion.

Medicine does not stand still, and now many wireless sensors are appearing. They do not tie the expectant mother to the bed and do not restrict her movements. For especially demanding women, CTG has been invented that allows recording while lying in a jacuzzi.

Timely examinations allow you to track the progress of pregnancy, and, if there are deviations, help you react in time and give birth to the baby.

The expectant mother should not worry if the attending physician sends her for the required examination in the form of cardiotocography.

How is CTG done?

Preparation

Before performing cardiotocography, the patient does not need the necessary preparation, but it is still better to approach this procedure responsibly. Before cardiotocography, it is advisable to get a good night's sleep and eat some sweet product that will lift your spirits. to the expectant mother mood and, thus, will allow the baby to move more actively.

Before starting the examination, it is better to visit the ladies' room, since the procedure lasts more than thirty minutes. It is carried out mainly in a supine position, but if a woman cannot take this position for a long time, then it is better to warn the doctor about this in advance.

And the most important requirement for the patient is to remain calm during the examination. From an excess of excitement, the baby will begin to move more actively.

The child does not feel the cardiotocography apparatus itself at all, but the expectant mother feels the excitement well. Therefore, you should be more relaxed about the procedure. And all the required work is carried out by equipment and a medical worker.

Video about cardiotocography

Carrying out the procedure

Cardiotocography is a non-dangerous and non-painful procedure for both the expectant mother and the child. The abdomen is treated with a special gel, and a sensor is attached there with a wide tape to record the contractions of the fetal heart. A pressure sensor is installed slightly below the navel area, which records the tone of the uterus.

Every time the baby begins to move, the patient needs to press a special button, which is provided by the medical professional conducting the examination.

Recording of information is carried out at a time when the baby is awake and more active. Based on the results of cardiotocography, a schedule is drawn up for special paper, which displays changes in heart rate.

The procedure is usually performed on a couch. A horizontal position is accepted, for example, lying on your back or on your side, it all depends on the woman’s desire.

Is the examination harmful or not?

Cardiotocography during pregnancy is a harmless procedure for mother and child. If required, it is carried out several times throughout pregnancy, and sometimes even every day. But still, under any circumstances, the study is done only as directed by the doctor.

The results obtained are considered together with the results of other examination methods, such as ultrasonography and Doppler. After this, only the doctor can make a conclusion.