What does fetal ktg mean. What is CTG during pregnancy? Physiological rationale for CTG during pregnancy
After 7 months of pregnancy, the expectant mother can get a referral for CTG. This study in the last trimester is considered one of the most informative. However, it is precisely this that causes the most questions among pregnant women, since it is completely unclear how and what is being investigated and how to understand what is written in the conclusion. In this article, we will talk about CTG in more detail, and also help to decipher its results.
What it is?
Behind the abbreviation CTG is a study called cardiotocography. At its core, it is a constant, continuous recording of the baby's heartbeats, uterine contractions, as well as the child's motor activity. All these parameters are fixed synchronously and are immediately recorded in real time by a chart recorder or a computer program on a calibration tape.
The rhythm of a beating baby heart is captured by an ultrasonic sensor, and uterine contractions are detected by a strain gauge sensor.
The first graph is called the tachogram and the second one is called the histogram. Due to its simplicity, safety and information content, CTG is today the most popular way to obtain information about the child's condition, which before the birth is very little - a couple of months.
CTG is prescribed for all pregnant women who are registered at the dispensary in the antenatal clinic. With an uncomplicated, normal pregnancy, the first study is carried out for a period from 30 to 32 weeks, then a similar examination is carried out immediately before childbirth in the maternity hospital during planned hospitalization. If the baby's condition raises questions, then CTG can be performed earlier, starting from 28-29 weeks. In case of serious complications of pregnancy, the examination can be carried out daily.
CTG is also used in the generic process itself. An examination during pregnancy, when the sensors are placed on the abdomen of the expectant mother, is called external or indirect CTG. Direct cardiotocography is performed when the integrity of the fetal membrane is broken, the water has broken, while a thin sensor-electrode is inserted directly into the uterus.
What does it show?
CTG allows you to find out how the child feels. First of all, the device captures and shows the heart rate (heart rate) - the main parameter that allows you to judge the well-being of the crumbs. An ultrasonic transducer based on the Doppler effect sends out an ultrasonic wave. It bounces off tissues and moving blood cells in the blood vessels and is sent back to the sensor. As a result it becomes obvious with what frequency the small heart beats.
The tone of the uterus and fetal movements are measured by a strain gauge, which is a wide belt encircling the belly of the expectant mother.
If the uterus contracted or tightened, if the baby made a coup or stretched, the stomach will change slightly in volume, which will not escape the sensitive sensor and will immediately be reflected in the graph.
There are some nuances in the study that are very important for correct diagnosis. So, not only the frequency with which the baby’s heart beats is important, but also how this rhythm changes depending on activity, movements and other factors. Therefore, rhythm variability, the myocardial reflex (when moving, the heart beats faster), as well as any other periodic changes in the child's heart, are evaluated.
Indications for examination
Like any other analysis or procedure, CTG during pregnancy is only a recommended technique, the Ministry of Health strongly advises pregnant women not to give it up. But the final word, in any case, remains with the expectant mother - if she does not want to go for this diagnosis, no one can force her.
Doctors try to do research for all pregnant women. But the procedure is especially indicated for certain categories of expectant mothers:
- Any pathology of pregnancy. These include gestosis, oligohydramnios and polyhydramnios, the threat of premature birth, infectious and non-infectious diseases that the expectant mother suffered during the period of bearing the baby, chronic ailments that she has, high or low blood pressure in a woman, etc.
- Strange child behavior. If the baby suddenly began to move rarely and sluggishly, or, conversely, his motor activity increased.
- The appearance of pain in the abdomen of the mother. Any pain syndrome, of any nature and strength, necessarily needs a CTG.
- Burdened obstetric anamnesis. The baby should be monitored more often with the help of cardiotocography if the woman’s previous pregnancies ended in premature birth, the death of the child in utero, and the birth of a child with gross developmental pathologies.
- Severe previous birth or caesarean section. If such facts occurred in the past, then the next pregnancy in the later stages necessarily needs frequent monitoring, including with the help of CTG.
Women from the designated risk group can be diagnosed several times during pregnancy. The frequency is determined by a doctor who is well aware of the peculiarities of the course of pregnancy in a particular woman.
How is it carried out?
This simple examination can be done in the antenatal clinic at the place of residence, as well as in any private clinic that offers pregnancy planning and management services. The procedure is completely painless, it does not cause any discomfort.
In the doctor's office, the woman will be asked to make herself comfortable. She can lie down, sit down or sit in a semi-sitting position, the main thing is that she is comfortable, since CTG lasts quite a long time - from half an hour to an hour, and in some cases longer if the examination fails or its results are abnormal or questionable.
A wide special belt is put on the belly of the expectant mother - the same strain gauge, and a small round or rectangular ultrasonic sensor is fixed under it. They try to position the ultrasound sensor so that it is as close as possible to the baby's heart. As soon as the doctor hears a distinct rhythm, he will fasten his belt, fix the sensors and start the computer program, which will begin to record indicators and draw graphs. If the examination is carried out on an old apparatus, a recorder will draw.
Movement will be captured by a strain gauge belt. If the diagnosis is made on the device, then the woman will have a button in her hand, which she will be asked to press every time she feels a distinct movement of her baby. The decision to stop measurements is made by the program itself, as soon as the amount of information necessary for calculating the results is received, the “session” will end and the result will be printed.
Preparing for the passage of CTG is quite simple. On the eve, it is desirable to have a good rest, sleep, so as not to get distorted unreliable results. You should not go to the study on an empty stomach, it is best to eat before going out, and before going to the doctor's office, go to the toilet, because you will have to sit in one position for a long time. Along the way, it is worth walking to “cheer up” the baby, because the sleeping fetus will not be able to demonstrate the necessary physical activity.
According to expectant mothers, a small chocolate bar eaten before the procedure helps to wake up the baby.
Decoding and norms
Modern devices not only immediately after the end of the examination give the result for each of the determined indicators, but also assess the general condition of the fetus in points. We will talk about the scoring a little later, but for now let's look at what the basic terms mean and what it should be like in the norm.
Basal Rhythm
The rate of contractions of a small heart is constantly changing. This is the first thing a woman sees. In order to average indicators that vary from 120 to 180 beats per minute, a parameter such as basal rhythm was derived. During the first 10 minutes of the study, the device captures changes in heart rate and displays the average basal value. That is what is indicated opposite the line "Basal rhythm" or "Basic heart rate". The norm in the third trimester is considered if the base frequency is in the range from 110 to 160 beats per minute.
Rhythm variability
If the basal rhythm is an average value, then those very rapidly changing indicators of the heart rate of the crumbs are the variability. The term is used to refer to this parameter. "oscillations", which literally means "fluctuations".
These oscillations are either fast or slow. Rapid or (instantaneous) oscillations are oscillations that occur with each beat of the baby's heart. On the monitor, mom will be able to see them like this: 143, 156, 136, 124, 141 and so on, because the heart changes rhythm every few seconds.
Slow oscillations are also different. If in 1 minute the heart of the crumbs changes the rhythm by less than three beats (it was 140, now it is 142), then we are talking about low variability and low oscillations. If in a minute the heart changed the rhythm of the beat by a number from 3 to 6 beats (it was 140, it became 145), then we are talking about average variability. When the heart rate changes by more than six beats per minute (it was 140, it became 150), they speak of high variability and high oscillations.
Oscillations are high and instantaneous.
If the baby has low variability and instantaneous oscillations, this may indicate serious pathological conditions of the crumbs. This is often seen with hypoxia.
Slow fluctuations can be monotonous (if the heart rate has changed by no more than five beats per minute of the study), transient (the rhythm has changed by 6-10 beats), undulating (heart rate has changed by 11-25 beats in 1 minute), as well as jumping (more than 25 beats per minute). Wave-like slow oscillations are considered normal. Any other types of slow fluctuations are regarded as an alarming symptom. Jumping, in particular, occur when entwined with the umbilical cord, and transitional - with hypoxia.
Accelerations and decelerations
These are the same “teeth” and “failures” that are discussed by expectant mothers and visible on the chart. In simple terms, acceleration is the rise in the child's heart rate by more than 15 beats per minute and maintaining this pace for 15 seconds or more. On the graph, this is an upswing. Deceleration is a decrease in the rhythm by the same 15 beats per minute while maintaining the pace for 15 seconds or more. On the chart, they look like a failure.
2 or more accelerations per 10 minutes are considered normal. If the “peaks” on the chart repeat with the same frequency and last the same amount of time, then this may be a sign of fetal distress. Decelerations are not considered normal at all. Most often they talk about possible hypoxia, but minor “dips” can also be a variant of the norm, it all depends on the rest of the CTG indicators.
Fetal movements
Many expectant mothers believe that the number of baby movements per hour is the main parameter that determines CTG. This is wrong. Already at least because there is no single norm for the number of movements of a child per hour. It is conditionally considered a good sign if the baby makes 6-8 or more movements per hour of diagnosis. The number of movements can be affected by the mood of the mother at the time of the CTG, and what she ate, and how her metabolism proceeds. The baby may be alert, or may want to sleep. That's why the number of movements is looked at only in conjunction with the rest of the diagnostic results.
The contractions of the uterine muscles look like smooth wavy lines on the graph, which is located under the graph of the fetal cardiogram.
Movements are noted in the same place, but they look like sharp rises, peaks.
A small number of movements may indicate that the baby is sleeping or in the resting phase, as well as that he has severe disorders, for example, oxygen deficiency. But no conclusions can be drawn from this indicator alone.
Uterine tone
Many pregnant women are concerned about the question of whether CTG will show uterine tone or hypertonicity. Answering it is not as easy as it seems. As mentioned above, CTG can be carried out in two ways - external and internal. The external method in question does not give an unambiguous answer about whether a woman has an increased tone. It only allows you to record individual contractions of the reproductive organ.
It is possible to accurately know the level of pressure inside the uterine cavity (and it increases with tone) only with the help of the introduction thin electrode-sensor into the uterine cavity. During pregnancy, for obvious reasons, this is impossible if the fetal bladder is safe and sound. And in childbirth, there is usually no need for such a measurement, because the baby has already gathered “to go out”, and measurements of external CTG will be informative, which will tell about his heartbeat and activity.
Therefore, by default, intrauterine pressure at the level of 8-10 millimeters of mercury is considered the norm.
If the program, when assessing the contractility of the uterus, shows values higher, they talk about tone, but indirectly and very carefully.
Contractions - true and false
Contractions are contractions of the muscles of the uterus, and they are displayed on the CTG chart. Moreover, both real contractions that accompany the birth process, and false or training contractions that precede the onset of labor, sometimes long before them. On the chart, real contractions are depicted as fairly large waves in the bottom line. Training will look similar, but the "waves" will be less pronounced, and the duration from the beginning to the end of the wave will be no more than a minute.
If we simplify all of the above, then the norms of CTG, under which it will be possible to say that everything is fine with the child, can be displayed in the following table:
Possible violations and their causes
Like any other diagnostic examination, CTG, or rather, its results, can raise a lot of questions, especially if the doctor says that "CTG is bad." What pathologies can be identified, we will describe below.
sinusoidal rhythm
The CTG schedule, which resembles even, identical sinusoids, usually does not inspire optimism for specialists. True, this happens quite rarely - once in 300-350 examinations, only in one woman theoretically cardiotocography shows a sinusoidal rhythm.
On the graph, decelerations and accelerations (ups and downs) are completely absent, while the base heart rate is quite normal, the variability does not exceed 15 beats per minute. Such a schedule usually does not bode well. This is how a child behaves with severe Rhesus conflict, significant fetal hypoxia, in case of poisoning of a pregnant woman and a baby with toxic substances or drugs.
If a woman has not taken poisons and drugs, the risks for the child increase. In this case, a sinusoidal rhythm may be a harbinger of imminent death. Almost 70% of children who demonstrated such sinusoids on CTG were born dead or died in the first hours after birth due to various reasons.
In order to judge the sinusoidality of the rhythm, like this, as in the picture, the graph should be “drawn” for 20 or more minutes. In this case, the woman is urgently hospitalized to perform an emergency caesarean section and try to save the life of the child.
High fetal heart rate
If a child has a clear excess of heart rate on CTG for 10 minutes, the base heart rate consistently exceeds the norm, we are talking about fetal tachycardia. At the same time, great importance is given to how exactly the main values \u200b\u200bare exceeded:
- Heart rate \u003d 160-179 beats / min - a mild degree of tachycardia;
- Heart rate = 180 beats / min and above - severe tachycardia.
The reasons that can make a small heart beat so often can be different. Most often, tachycardia is a sign of oxygen starvation. When a baby does not have enough oxygen, compensatory mechanisms “turn on” in him, which are designed to saturate tissues and organs with oxygen “for future use”. The heart begins to beat faster under the influence of stress hormones.
With a high heart rate, a baby in the womb can respond to a fever. If the mother's body temperature rises to at least 37.5 or 38.0 degrees, the baby will immediately demonstrate an increase in heart rate. If the mother is not sick and does not complain about a rise in temperature, the cause of such CTG may be infection in the baby. Intrauterine infection causes the baby's immunity to begin to produce antibodies and a variety of auxiliary substances that increase the temperature of the child himself and make his heart beat faster.
If the mother has taken any medication shortly before the study, this must be reported to the doctor.
Side effects of some drugs include an increase in heart rate, and not only in the mother herself. Tachycardia can be observed in the children of women suffering from an abnormal thyroid gland. In this case, the baby's body acts wrong hormonal background of the mother.
Slow fetal heart rate
A decrease in the baby's heart rate below normal values is called bradycardia. An alarming indicator is heart rate if it remains at the level of 100 or less beats per minute for 10 minutes of the study or more.
Slow heart rate may be due to severe hypoxia, representing a real danger to the life of the baby. Such indicators during the birth process indicate that the baby's head was tightly pressed when passing through the birth canal. In the second case, bradycardia is considered a variant of the norm, it is called reflex arrhythmia. Some medications that the mother took on the eve of the study can also slow down the heart rate of the child.
monotonous heartbeat
Such a violation can be discussed when slow oscillations (oscillations) do not exceed 5 beats per minute. There are no sharp fluctuations on the chart. If this schedule remains for 10-15 minutes of the study or more, the woman will definitely be asked to undergo additional examinations, for example, ultrasound with ultrasound, because monotony in most cases “signals” about hypoxia and other circumstances unfavorable for the baby.
Fetal hypoxia - oxygen starvation
All expectant mothers know how dangerous and insidious hypoxia can be. The oxygen deficiency that the baby receives with maternal blood through the mother-placenta-fetus system can lead to irreversible processes in the baby’s central nervous system and even provoke his death.
Signs of crumb hypoxia on a cardiotocographic examination are a decrease or increase in heart rate.
At the early stage of oxygen starvation, the heart beats more often than required by the norm, at the late stage of hypoxia, there is a decrease - bradycardia.
The baby, who suffers from a lack of oxygen so important for his development, will “demonstrate” low variability on CTG, accelerations that will be exactly the same in duration and severity, a sinusoidal rhythm and sharp, very frequent movements, which doctors call “painful movements”.
If CTG determines one of these signs, then the woman is sent for additional examinations. But detection of two or more alarming indicators is the basis for hospitalization expectant mother and speedy delivery by caesarean section.
Score by points
To summarize the results of cardiotocography, a scoring system is used. The evaluation of each of the above parameters includes the accrual of a completely certain number of points, which in total give the final result. In obstetrics and gynecology, there are several criteria for "awarding" points.
Fisher scale
Of all the methods for calculating the results, this one is considered to this day the most accurate and correct. When scoring on the Fisher scale, four main values \u200b\u200bare evaluated - the base heartbeat, variability, acceleration and deceleration. This scale was supplemented by Dr. Krebs, who also suggested taking into account the number of fetal movements. This resulted in a clear and simple scoring system:
Fischer rating table in Krebs modification:
| The indicator determined on CTG | 1 point is awarded if: | 2 points are awarded if: | 3 points are awarded if: |
|---|---|---|---|
| Base heart rate | Less than 100 bpm or more than 100 bpm | 100-120 bpm or 160-180 bpm | 121-159 bpm |
| Expression of slow oscillations | Less than 3 bpm | 3 to 5 bpm | From 6 to 25 bpm |
| Number of slow oscillations | Less than 3 during the study period | 3 to 6 per study period | More than 6 during the study period |
| Number of accelerations | Not fixed | 1 to 4 in half an hour | More than 5 in half an hour |
| Decelerations | late or variable | Variable or late | Early or not fixed |
| perturbations | Not fixed at all | 1-2 in half an hour | More than 3 in half an hour |
Normal on this scale is considered if the condition of the fetus is estimated at 9-12 points. This means that the baby feels good, in any case, while the study was being conducted.
If the result of CTG according to Fisher is 6-8 points, then the woman needs further monitoring of CTG, because such an indication is a sign of the child's distress. However, it does not pose an immediate danger to the life of the crumbs. It is recommended to repeat CTG more often to monitor the dynamics.
The most alarming indicator according to Fisher is less than 5 points. This means that the child is in mortal danger, his death can occur at any moment. Usually, with such results, CTG is not sent home, but immediately to the hospital, where a decision on early delivery should be made within the next few hours in order to give the baby a chance to survive. This is the very case in which it is more dangerous for a child to remain in the womb than to be born, even if very premature.
FIGO scale
This scale was created by the International Association of Gynecologists and Obstetricians in order to “equalize” some errors in the assessment of CTG criteria by doctors from different countries. This is the international "gold standard".
FIGO score table:
Common Questions
What is a PSP?
In the conclusion that the pregnant woman will receive after undergoing cardiotocography, it will be indicated that the PSP of the fetus \u003d a certain numerical value. What is PSP is not too difficult to guess. This abbreviation is deciphered as follows: "an indicator of the condition of the fetus." This is a kind of summary that is issued after analyzing all the data received. It is not a person who calculates the PSP, but a special program, and therefore the personal factor and the qualifications of the medical staff do not matter here.
PSP is calculated by complex mathematical algorithms that the expectant mother does not need to know at all. It is enough to familiarize yourself with the general rules of the PSP as such:
Norm - 1.0 and below. A deviation from the norm, which is considered insignificant, for example, 1.03 or 1.05, is a reason to double-check the data, conduct CTG again, perhaps something just went wrong.
PSP \u003d 1.1-2.0. These numerical values indicate the initial disturbances in the condition of the fetus. In this case, CTG should be repeated once a week, the woman is prescribed treatment depending on the causes that caused the violations (fetal hypoxia, placental insufficiency, etc.).
PSP \u003d 2.1-3.0. Such indicators indicate that the baby feels severe discomfort, his condition leaves much to be desired. With such values in CTG, it is customary for a woman to be hospitalized in order to make the final decision in the hospital - to treat or give birth. If it is decided to keep the pregnancy, a cardiotocogram will be shown every 2-3 days.
PSP= 3.0 and above. This result is very worrying. Most often, it indicates that the baby is in critical condition. A woman is hospitalized immediately, sometimes by ambulance, within a few hours a decision is made to conduct an emergency caesarean section to save the baby's life.
Is the gender of the baby visible on the CTG?
The genitals of the child, as well as other features of his appearance and structure, are not indicated in any way on cardiotocography. The sensors that the doctor attaches to the belly of the expectant mother do not give an image of what is happening inside on the screen, they only “write” graphs.
To find out the sex of the baby, it is better to go for an ultrasound or donate blood for a non-invasive DNA test.
These methods will answer with great accuracy the question of who is growing in the stomach - a son or a daughter. Attempts to determine the sex of the child by the heart rate, which is determined by CTG, cannot be explained by any scientific arguments. Folklore says that a boy's heart beats less than a girl's heart. . Traditional medicine can neither confirm nor deny this - this pattern has not been studied.
How to do CTG during twin pregnancy?
This question interests many, but the answer to it is not so simple. One sensor can register parameters for only one baby. If there are two or more children in the mother's womb, this can cause a lot of technical difficulties during the procedure.
To avoid confusion when assessing the condition of two or more babies, the doctor will first determine the location of each of them. Separate ultrasonic sensors will be attached to the area close to the heart area of each baby. If there are two children, then there will be two ultrasound sensors, if there are three, then there will be three sensors. But the strain gauge, as in normal pregnancy, will be one. Thus, a woman will receive two or three graphs, the same number of conclusions on the condition (PSP) of each of the babies she bears.
What is a positive and negative non-stress test?
Additional tests can make CTG results more accurate. CTG with functional tests can be prescribed separately if the results of the first study turned out to be “suspicious”, doubtful or borderline (between the norm and pathology). The tests are different. A stress test is a registration of the reaction of the fetus, its heart rate and other parameters after the introduction of a pregnant woman with a small dose of oxytocin, which causes uterine contractions.
A woman may be asked to walk briskly up the stairs before the examination, hold her breath from time to time, all of these will be options for stress tests.
A non-stress test is when no load and provoking factors from the outside are observed on the child, and the baby will respond to its own movements with an increase in heart rate.
If acceleration after movement is not observed, this is an alarming sign, the test is considered positive. If in 40 minutes the baby makes at least two movements with accelerations, then the test is assessed as negative, and this is considered the norm.
What will the study show if the baby is sleeping?
If the examination is carried out at the moment when the baby is in the resting phase, then his movements, like a sleeping adult, will be minimized. The CTG will record the heart rate, as well as episodic uterine contractions, but there will be no movements or they will be single, there will be no accelerations associated with them. In this case, the doctor will take all measures to wake up the "sleepy", if this does not work out, that the woman will be advised to come to the CTG again, in a few days.
What will the study show if a woman has oligohydramnios?
Cardiotocography cannot confirm the fact of oligohydramnios (as well as polyhydramnios), this can only be clarified by ultrasound. However, with the established fact of oligohydramnios, CTG will be done more often. If the results in dynamics indicate the prenatal suffering of the child, then the woman will be shown early delivery. This is not always the case, and many expectant mothers with oligohydramnios get excellent results of cardiotocography.
Can CTG harm the fetus?
Cardiotocography is considered a completely safe method for the child and mother. Despite this, many women argue that doing ultrasound is harmful, as well as CTG, where an ultrasonic sensor is also used. The harm of ultrasonic radiation for the development of the child has not been proven. True, it is not yet possible to assess the isolated consequences of exposure to ultrasonic radiation on a person (in ten, twenty or forty years).
Thus, only illiterate actions of medical personnel can harm the baby, which can tighten the strain gauge-belt on the pregnant belly too tightly, causing mechanical compression and even injury to the fetus.
Do CTG parameters change week by week?
It makes no difference how long the CTG is performed. The parameters that are determined in this study do not depend on the height, head circumference, chest or limb length of the child, as is the case with ultrasound. Therefore, the results of CTG at 33, 35 and 36 weeks will not differ in any way. If the child is comfortable and well, then this is exactly what the graph will show.
Experienced obstetricians, however, note one curious detail - the baby's heart begins to beat a little less frequently at 32.34, 36 and 38 weeks.
Can the procedure be done at home?
Theoretically and practically, this is possible, but the cost of devices for cardiotocography is high (several hundred thousand rubles), and small amateur devices that only record the heart rate and do not record or analyze other parameters have no special diagnostic value.
Sometimes, when the situation requires daily monitoring, a woman is temporarily provided with a device for home use, this decision is made by the attending physician. Most often this happens with patients of modern perinatal centers, which are better equipped than consultations.
Home measurements will be able to show the condition of the baby, as well as understand that there will be childbirth soon, if the baby is moving strongly or, conversely, has calmed down, and characteristic “waves” appear on the graph, indicating the onset of contractions and preparation for childbirth. This can happen at any time, starting from 37-38 weeks. Women whose onset of labor should not coincide with their stay at home are advised to go to the maternity hospital in advance. In a hospital setting, if necessary, a daily CTG will be performed, and the expectant mother will not have to worry about the condition of her baby.
For information on how CTG is carried out, as well as other useful information on pregnant women, see below.
The number of CTG performed increases during twin pregnancy and overgestation (more than 41 weeks). These conditions require increased attention from doctors. Therefore, how many times CTG is done during a post-term pregnancy is determined by ultrasound indicators, general physical condition, and the results of clinical tests.
Studies are carried out every five days after the expected (estimated) date of delivery. If intrauterine hypoxia is detected, monitoring is carried out daily until the child's condition is normalized. Depending on how long the CTG indicators are taken during pregnancy, the therapy regimen is determined, and a decision is made on the method of delivery.
How to prepare for CTG
Special preparation for CTG during pregnancy is not needed. The optimal time for the study is from 9 am to 2 pm and from 7 pm to 11 pm. When undergoing the procedure at other hours, deviations in heart rate variability may be observed. It affects the indications of CTG during pregnancy and the position that the woman takes at the time of the study. The optimal position during cardiotocography is lying on the left side. A sitting/semi-sitting position is allowed. Body position can affect how long CTG takes during pregnancy.
It is not recommended to lie on your back during the procedure. Due to excessive compression of the uterine cavity of the blood vessels, it is possible to obtain unreliable results. The process of how to prepare for CTG during pregnancy includes a visit to the gynecologist to listen to the heartbeat and determine the location of the fetus. Before the procedure, you need to sleep well, visit the toilet, tune in to a positive mood.
Is it possible to eat before CTG during pregnancy?
Electronic monitoring is not done on an empty stomach and after direct (intravenous) administration of glucose. This affects the activity of the child and causes errors in the tocogram. Therefore, the answer to the question of whether it is possible to eat before CTG during pregnancy is positive. The optimal time interval after eating is 2-3 hours.
Features of the procedure
The main thing that CTG gives during pregnancy is the ability to determine whether the baby has enough oxygen, how he tolerates physical activity during uterine contractions, and whether he will pass through the birth canal. There are two methods of how CTG is performed during pregnancy: indirect and internal.
The second method is used extremely rarely and only in childbirth. The first is actively used during the period of gestation and in the first phase of labor. Cardiotocography during childbirth shows how well the child copes with the load and whether additional stimulation of the birth process is required. Consider how CTG is done during pregnancy.
The principle of how CTG is done during pregnancy includes the main steps:
- Placement of the ultrasound sensor on the anterior abdominal wall in the zone of audibility of the child's heartbeat. The correct location of the controller affects how long CTG will last during pregnancy.
- The imposition of a strain gauge in the right corner of the uterus.
- Fixing the reader with straps.
- Fixing data for an hour / half an hour on a paper tape in the form of graphs.
The results obtained are interpreted by an obstetrician-gynecologist. A comprehensive assessment of CTG, Doppler and ultrasound data is being carried out. If, according to the results, pronounced hypoxia is observed, measures are taken to eliminate it.
Total duration of CTG
How long does CTG do during pregnancy?
The duration of this procedure varies from 30 minutes. up to one and a half hours. You can find out exactly how long CTG will last during pregnancy from the doctor conducting the procedure. In some cases, it takes no more than 20 minutes to compile a complete picture. The main factor affecting how long CTG is done during physiological pregnancy is the motor activity of the child.
The total time of the CTG procedure during pregnancy is 40-60 minutes. The estimated time also depends on the general well-being of the woman and how often CTG is done during pregnancy.
Norms and decoding of CTG during pregnancy
What exactly does CTG show during pregnancy:
- condition of the fetal heart;
- the presence of intrauterine infections;
- developmental anomalies;
- fetoplacental insufficiency.
The study assesses the age of the placenta and the risk of preterm birth.
For a correct assessment of the health of the fetus, it is important to understand how CTG is deciphered during pregnancy. When conducting a study and interpreting the results, it is taken into account that the average duration of fetal sleep is about half an hour.
Changes in the biochemical parameters of the mother's blood affect the general motor activity of the child, the ability to respond to stimuli. For example, a change in glucose levels. A full decoding of the CTG of the fetus during pregnancy is performed by an obstetrician. The obtained data correlate with generally accepted standards. How to decipher CTG during pregnancy on your own? To do this, you can use tabular data.
Table 1. Indications of CTG during pregnancy decoding
Correct interpretation of CTG data during pregnancy helps to determine further treatment tactics, resolve the issue of methods, terms of delivery.
A CTG indicator during pregnancy of 6 points may indicate intrauterine growth retardation, insufficient oxygen supply. Reduced heart rate as a variant of the norm is possible with a breech presentation of the baby.
What does the CTG device show during pregnancy. Decryption:
- SS frequency (basal rhythm).
- Character, amplitude of tones (variability of BR).
- Rhythm (deceleration, acceleration).
Table 2. CTG indicators during pregnancy are the norm by week.
What is CTG analysis during pregnancy? The concept implies an assessment of tokogram indicators to identify deviations from the recommended physiological norm.
Table 3. CTG during full-term pregnancy is the norm (32-38 weeks):
Poor CTG during pregnancy indicates deviations in the reactivity of the baby's cardiac and vascular system. The information obtained during the study reflects changes in the structure of the mother-placenta-fetus. However, by one indicator of cardiotocography, it is impossible to draw final conclusions about the condition of the child. The optimal indicator of CTG during pregnancy is 9 points.
Harm CTG: truth or myth
The CTG procedure during pregnancy is painless and safe. It does not harm the baby and the expectant mother, does not stimulate the premature onset of labor. Timely conduct of cardiotocography reduces the risk of developing pathologies, allows you to identify them in the early stages, take the necessary measures to eliminate them.
Update: December 2018
When the expectant mother feels the fetal movements, this is wonderful: a pregnant woman knows that the baby is doing well. But by motor activity it is impossible to assess the possible onset of intrauterine suffering in a child.
In order to detect and prevent problems in time, it is necessary to use ultrasound research methods (CTG, ultrasound and dopplerometry). Fetal cardiotocography (CTG) is a simple and affordable method for assessing a baby's heartbeat, with which you can notice the initial signs of oxygen deficiency.
In addition, it is possible to identify changes in the muscle tone of the uterus in a woman, which can cause premature birth. CTG is a technique for recording uterine tone and heart rate on special calibration paper. That is, 2 graphs are being maintained, some devices can record the child's motor activity:
- heartbeats detected by ultrasound
- uterine tone, determined by a strain gauge
Is cardiotocography harmful to the fetus?
This is an absolutely safe procedure for both the fetus and the woman, does not cause discomfort and can be performed according to indications even daily (in case of fetal hypoxia), to assess the effectiveness of the therapy and make a decision on emergency delivery.
Indications for CTG
The most informative method in the last trimester of pregnancy. It is after 30 weeks that the biorhythms of the fetus are fully established (“activity-sleep” cycles) and a specific reflex is formed (increased heart rate during fetal movements), by which one can judge the full provision and normal intrauterine development of the child (see). The main indications for CTG during pregnancy include:
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Complicated pregnancy:
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Diseases in the fetus, identified by ultrasound examination:
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Serious illness in a pregnant woman:
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In the cases listed in the table, CTG should be carried out more often, up to daily. The state of the fetus and the effectiveness of labor activity also allows you to evaluate cardiotocography in real time.
Research methodology
Most often, the examination is carried out at 32 - 34 weeks of pregnancy. CTG is performed in the position of the pregnant woman on her back with a small roller under the right side (the optimal position is a slight turn to the left side). It is possible to perform CTG in a position lying on its side, or sitting, leaning back in a chair.
When CTG is done, the study is carried out using sensors with a frequency of ultrasonic waves of 1.5-2 MHz, which is absolutely safe for the fetus even with prolonged exposure. Any modern device has the ability to assess the vital activity of two fetuses at the same time, which is used in women with twins.
Types of devices
In medical institutions, there are various options for assessing the baby's heartbeat. Most often, the doctor simply listens to the baby's heart rhythm with an obstetric stethoscope, but if there is any doubt (or if there is evidence), a special device must be used. What are the types of CTG devices?
- CTG without automatic analysis
These obsolete devices are usually quite rare in modern hospitals, but they can still be found in remote corners of our country. The main inconvenience of these devices is that the doctor must independently evaluate the fetal heart rate graph. If the doctor has experience and owns this technique, then the effectiveness of these devices is no lower than that of new CTG devices.
- CTG with computer analysis
Modern cardiotocographs not only record the graph, but also independently process the data. The doctor only needs to read the finished result and decide on the need for treatment. This variant of CTG is used in medicine most often.
- CTG-online
The modern mobile era offers a great option for monitoring the baby with a special sensor attached to the skin of the abdomen and a smartphone connected to the Internet. Information about the fetal heartbeat is transmitted in real time to the web portal, processed and provided as a ready-made report to the doctor. Unfortunately, while CTG-online is used quite rarely.
CTG decoding: pathology or norm
The table below shows the assessment of the condition of the fetus by CTG, proposed by Dr. Savelyeva, which takes into account all indicators:
- basal rhythm - the average frequency of contractions of the fetal heart
- variability - a change in the frequency and amplitude of the heart rate (deviation from the frequency of the basal rhythm
- acceleration - acceleration of the heart rate from the basal, more than 15 beats, lasting more than 10-15 seconds.
- deceleration - a decrease in the fetal heart rate from the basal one, by more than 15 beats, lasting more than 10 seconds.
- fetal activity
Bad CTG during pregnancy will be when the following indicators are detected:
- prolonged increase in fetal heart rate (tachycardia) more than 160 beats per minute
- baby's heart rate slows down to less than 110 beats per minute
- increased rhythm variability with an amplitude of more than 25 beats per minute
- decrease in variability below 5 beats per minute
- sinusoidal rhythm, in which there is a uniform and monotonous heartbeat without any fluctuations and changes in variability
- appearance of decelerations
After counting the points, the condition of the fetus is assessed:
- 5 or less - the state of fetal hypoxia, the child experiences oxygen starvation
- 6, 7 points - the first signs of fetal hypoxia
- 8, 9, 10 points - no hypoxia, the child feels well
Motor activity in the Savelyeva method is not taken into account, however, you should be aware that increased, excessive fetal mobility, or vice versa, its absence, indicate the presence of oxygen starvation in the fetus.
However, even if deviations are found, this does not always indicate serious problems in the child. It should be taken into account not only CTG during pregnancy, the decoding of which will indicate the presence of hypoxia in the baby, but also the duration of pregnancy, the presence of complications in a pregnant woman, the data of an ultrasound study and dopplerometry.
What to do with a bad CTG
All methods for assessing the condition of the fetus are required for timely therapy aimed at reducing fetal hypoxia, the results of CTG during pregnancy are one of the most informative for this. This is especially true in the case when the examination reveals a pronounced suffering of the fetus and it is necessary to quickly make a decision to save the child's life. As a rule, in this situation, an emergency caesarean section is performed.
If there are moderate signs of insufficient blood supply to the fetus, detected by CTG, complex treatment is carried out. It is optimal to do this in a hospital, in an antenatal ward.
- The pregnant woman is shown complete rest
- Improvement of fetoplacental circulation (blood flow between mother and fetus)
Medicines are used that reduce the tone of the uterus, which leads to a better flow of blood from the uterine vessels to the placenta. To do this, use a solution of Ginipral for intravenous administration in the form of daily droppers. Antispasmodics (,) give a good effect. Also shown are Magne B6, Brikanil.
- Drugs to improve cellular oxygen permeability
It requires the appointment of drugs that improve metabolism - glutamic acid, vitamins C, E, glucose, neuroprotectors, antihypocants. As well as drugs that improve cell permeability - Essentiale forte, Lipostabil.
- Decreased blood viscosity
Considering that small vessels predominate in the placenta, it is necessary to improve the fluidity of the blood in order to prevent the formation of small blood clots. Curantil, Trental, Actovegin, Reopoliglyukin are prescribed, small doses of Aspirin can be used - ¼ tablets twice a day (see)
- Treatment of complications of pregnancy and diseases of a woman
With high blood pressure in a pregnant woman, antihypertensive therapy is indicated. With anemia, it is necessary to increase the level of hemoglobin, which carries blood with oxygen to the fetus (see). Correction of endocrine disorders and impaired kidney function in women are important.
- Accelerating the maturation of the baby's lungs
At a gestational age of up to 36 weeks, the respiratory system has not yet matured in the fetus, and the child may have problems with the first breath. If there is a risk of early delivery due to severe fetal suffering, then the development of lung tissue in the child should be accelerated. For this, injections of a corticosteroid (dexamethasone) are used.
- Oxygen cocktail
A woman can take an oxygen cocktail on her own, which can be purchased at pharmacies or special departments of stores for mothers and babies (“Ecotail”). The cocktail is made very simply, the kit includes gas cartridges, sachets with a mixture. Having diluted the mixture with apple juice, a solution is obtained, which is filled with oxygen through a special tube, 5 minutes and the cocktail is ready. With hypoxia in a child or for prevention, it should be used 3 times a day after 30 weeks (or even the entire pregnancy with 15 day breaks).
- After improving condition
With a decrease in the signs of fetal hypoxia and an improvement in the condition of the pregnant woman, aqua gymnastics, breathing exercises, UVI are recommended.
Complex therapy of fetal hypoxia is carried out under regular CTG control. If the treatment is ineffective or the cardiotocogram worsens for more than 28 weeks, to save the life of the child, doctors may decide on an emergency delivery.
Cardiotocography is an important component of a comprehensive assessment of the fetal condition along with ultrasound and doplometry. With the help of this procedure, doctors record uterine contractions and the heartbeat of a baby that has not yet been born. CTG allows you to identify any problems and start solving them in a timely manner.
Doctors who monitor the development of the fetus give women referrals for cardiotocography from the 30th week, but they can be issued earlier if there are certain indications for CTG during pregnancy.
Usually, the fair sex is advised to undergo CTG during pregnancy several times, namely during the third trimester 2 times. If the pregnancy is accompanied by complications, then medical professionals may prescribe an additional study.
CTG is also performed during childbirth. This is required in order to determine the general condition of the crumbs and decide on the further conduct of the birth process. Special control is required for babies in whom, according to the results of ultrasound, umbilical cord entanglement was detected.
How is CTG done during pregnancy?
Cardiotocography is a safe procedure. It will not harm either the mother or the child.
The question of how CTG is done during pregnancy is of interest to women who have never undergone this procedure. She is absolutely fearless. The doctor asks the woman to take a supine or semi-lying position. You just need to relax and sit comfortably on your back. Several sensors will be attached to the tummy:
- Ultrasonic, recording the baby's heartbeat;
- Strain gauge (pressure sensor), with the help of which uterine contractions are recorded.
Cardiotocography is carried out in a phase that is characterized by fetal activity. The doctor makes an appointment within 30-60 minutes. All data in the form of graphs is recorded by a special apparatus on a paper tape.
A woman should not forget preparation for CTG during pregnancy. It is recommended to sleep well before the procedure, tune in, forget about all the problems and fears and have a snack before it. You can eat a chocolate bar before cardiotocography so that the child does not sleep, but is more active. Before starting the study, you should definitely go to the toilet, as the procedure takes a long time.
Deciphering CTG during pregnancy
The doctor can show the results of CTG during pregnancy on a paper tape, which shows graphs-curves, or say by naming the number of points scored.
Deciphering CTG during pregnancy is not an easy task. Well, if the graphs do not cause absolutely no suspicion. Then the doctor and the expectant mother will not have to worry about anything. However, in life there are different cases. The results of CTG can be alarming. In such a situation, it is very important not to make a mistake. Any decision should be carefully thought out by the doctor, because every action and word affects the child.
Here is a vivid example taken from life: a young doctor, who had not yet gained experience, did not like the results of cardiotocography of one patient. He told the pregnant woman about his concerns, but she categorically did not believe the results of fetal CTG during pregnancy. One can easily imagine how the woman felt at that moment. The specialist called an ambulance, as he was worried about the patient's condition and the life of the fetus. In the maternity hospital in the pathology department, it later turned out that the pregnant woman had absolutely no abnormalities. With what mood will this patient come to the antenatal clinic next time?
It would be nice if the expectant mother would learn to interpret the results of cardiotocography in general terms. So it would be possible to avoid unnecessary waste of nerves and a collision with the above incident.
When deciphering cardiotocography and making a diagnosis, many factors must be taken into account, because the results are influenced by weather conditions, the mood of a pregnant woman, sleep or active wakefulness of children. Based on the results of poor CTG during pregnancy, it is not recommended to draw conclusions about the condition of the child in the tummy, because even an absolutely healthy baby may have “suspicious” graphics.
When deciphering a cardiotocogram, doctors take into account several basic parameters: basal rhythm, amplitude, as well as the frequency of deviations from it, slowing down and increasing heart rate. Each parameter is assigned 0-2 points. At the final stage, the points obtained are added up, and the condition of the fetus is assessed by their sum:
- 8-10 points- the norm of CTG during pregnancy;
- 6-7 points indicate the possible presence of initial signs of fetal distress. The doctor may prescribe an additional study;
- 5 points or less are an indication that a pregnant woman urgently needs hospitalization and care.
Heart rate assessment
The basal fetal heart rate should be 110-160 beats per minute. The graph clearly shows that ups and downs alternate. However, the doctor is not interested in the minimum or maximum values. It evaluates the mean.
A woman can independently evaluate what CTG shows during pregnancy. To do this, you need to move the printout to arm's length and drag your finger over the graph, as if drawing it in the form of a straight line. The level to which the line on the vertical axis will correspond will be the basal rhythm.
The study of cloves and teeth
The next parameter that doctors evaluate is the variability of the child's heart contractions. Having determined the basal rhythm, you can begin to study the frequency and amplitude of deviations from this rhythm.
The graph clearly shows that the curves have many small teeth and several large teeth. Small teeth show deviations from the basal rhythm. It is desirable that there be no more than 6 pieces per minute - this is the norm of CTG at 32-39 weeks of pregnancy. However, counting the number of small cloves is not so simple. Doctors often estimate the amplitude of deviations - changes in the height of the teeth on average, which should normally be 11-25 beats per minute.
Doctors may not like it if the change in the height of the teeth is 0-10 beats per minute. However, this can be quite normal if the baby feels comfortable in the mother's tummy and sleeps, or the gestation period does not exceed 28 weeks. Above the estimated rate of 25 beats per minute, medical professionals begin to suspect the presence of cord entanglement or fetal hypoxia.
Evaluation of accelerations and slowdowns
When evaluating increases and decreases in CTG at 32-38 weeks of pregnancy, you should pay attention to the large teeth shown in the graph. Doctors, doing cardiotocography on old devices, ask pregnant women to press a special button when the baby moves. Modern models no longer require this. They themselves are able to register the activity of the fetus. When a baby pushes, his heart beats faster for a few seconds. On the graph, this will be represented as a large tooth growing upwards. This is called accelerating. If there are at least 2 of them on the chart in a 10-minute period, then this will be considered a good sign.
increases may or may not be detected during the study. Do not panic because of this ahead of time. Maybe the baby hasn't woken up yet.
reductions - this is the complete opposite of acceleration. On the CTG chart for 35-39 weeks of pregnancy, they look like teeth growing down. There is no cause for concern if the acceleration on the graph is followed by a short and shallow decrease, after which the curve returns to the basal rate level. High-amplitude reductions can alert. However, before drawing a conclusion, you should pay attention to the 2nd graph, which is available on the printout. Contractions of the uterus, which are noted on it, can affect the occurrence of contractions.
In conclusion, it should be noted that the CTG method has several undeniable advantages. Firstly, thanks to this procedure, you can learn about the condition of the fetus and the nature of labor, quickly identify existing problems and find ways to solve them, and secondly, when CTG is done during pregnancy, there are no unpleasant sensations. The procedure is completely safe for mother and fetus. Thus, if expectant mothers are concerned about the question of whether CTG is harmful during pregnancy, then the answer is always unambiguous - it is harmless.
Pregnancy is an unusually joyful time for every woman who is preparing to meet her baby. But, in addition, pregnancy is also a very important period, because any mother wants the baby to “comfortably” live in her tummy, without experiencing any inconvenience and lack, so that it develops and forms according to all indications. In order to monitor how comfortable the baby is in the womb, in order to establish and correct any “malfunctions” in this regard in time, the pregnant woman has to undergo certain examinations if necessary. One of the most valuable examination methods doctors call CTG during pregnancy, which allows you to make a comprehensive assessment of the condition of the fetus.
CTG (cardiotocography) during pregnancy is performed in order to obtain results regarding the baby's cardiac activity and heart rate, as well as its motor activity, the frequency of uterine contractions and the baby's reaction to these contractions. CTG during pregnancy, together with doppleometry and ultrasound, makes it possible to determine certain deviations in the normal course of pregnancy in time, to study the contractile activity of the uterus and the reaction of the child's cardiovascular system to them. With the help of CTG during pregnancy, you can confirm (or refute) the presence (or absence) of conditions dangerous for the mother and baby, such as; intrauterine infection, low or polyhydramnios; fetoplacental insufficiency; anomalies in the development of the fetal cardiovascular system; premature maturation of the placenta or threat. If the suspicions of this or that deviation are confirmed, this enables the doctor to determine in a timely manner the need for therapeutic measures, to adjust the tactics of managing the pregnant woman.
When is CTG done during pregnancy?
To conduct CTG during pregnancy, a special apparatus is used, which consists of two sensors connected to a recording device. So, one of the sensors takes readings of the fetal heart activity, while the second one captures uterine activity, as well as the baby's reaction to uterine contractions. An ultrasonic sensor for listening to the fetal heartbeat and a strain gauge sensor for recording uterine contractions are attached to the pregnant woman's abdomen using special belts. One of the main conditions for the most effective fixation of readings is considered to be a comfortable position for a woman during CTG during pregnancy. So, the readings are taken when the pregnant woman is lying on her back, on her side or sitting, in any case, it is necessary to choose the most comfortable position. At the same time, the pregnant woman will hold a special remote control with a button in her hands, which she presses when the baby moves, which makes it possible to record changes in the heart rate during the movement of the fetus.
The most suitable time for cardiotocography is the third trimester of pregnancy, starting at 32 weeks. In addition to the fact that at this moment the fetal cardiocontractile reflex is already formed and the relationship between cardiac activity and motor activity is established, the activity-rest (sleep) cycle is also established. In principle, CTG can be performed earlier than the specified period, but the reliability of the diagnosis in this case is called into question.
The norm of CTG values during pregnancy
CTG indicators during pregnancy cannot be a reason for making a diagnosis, this is just additional information about the condition of the fetus at a given time interval. Moreover, to form a complete and most plausible conclusion about the life of the fetus, a single examination by CTG is not enough: cardiotocography must be performed several times.
The results of the CTG are displayed as a curve on the tape, evaluating the readings on which (curves), the specialist can determine whether there is any deviation from the recommended norm. And during the CTG, several indicators are evaluated:
- basal rate (mean heart rate), displayed as BHR or HR. The norm is 110-160 beats per minute at rest, 130-190 - with fetal movements;
- rhythm variability (mean height of deviations from the basal rhythm). Norm - 5-25 beats per minute;
- deceleration (or deceleration, slowing the heart rate). Shown on the chart as significant troughs. The norm is absent, and if it does occur, it is very short and shallow;
- acceleration (or acceleration, acceleration of the heart rate). On the graph, they are displayed as teeth. Norm - 2 or more accelerations in 10 minutes;
- tokogram (uterine activity). Norm - no more than 15% of the frequency of fetal heart contractions of uterine contractions lasting from 30 seconds.
Deciphering CTG during pregnancy is carried out according to a 10-point system, each of the criteria (moreover, in terms of variability, the amplitude of deviations and their number are assessed) scores from 0 to 2 points. The result is a holistic picture, according to which:
- from 9 to 12 points - the condition of the fetus is normal;
- from 6 to 8 points - the presence of hypoxia, but without high threats, a second procedure is required;
- 5 points or less - severe hypoxia requiring urgent delivery.
In the event that the results of CTG are extremely negative, the doctor decides on an artificial emergency “forcing” of events - inducing labor.
Is CTG harmful to the fetus during pregnancy?
CTG is a completely safe procedure that has no contraindications. Therefore, if the future mother is concerned about the question of whether CTG is harmful during pregnancy, the answer in this case is always categorical - it is not harmful. If necessary, you can conduct an examination for a sufficiently long time, and even daily. Moreover, the examination is very, very informative, it allows you to determine the probable threats to pregnancy and the fetus in time, and take the necessary actions in a timely manner. But, in any case, the obtained analyzes should be considered only in the context of the general course of pregnancy and in interconnection with the results of other examination methods, in particular ultrasound and doppleometry.
Especially for- Tatyana Argamakova
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