What do the percentages per kg of the fetus mean. During pregnancy, KTG: decoding. What is a non-stress test
There are some methods of ultrasound diagnosis of the condition of the fetus in expectant mothers, which are considered absolutely harmless to the baby. One of these methods is cardiotocography ( CTG) during pregnancy, normal or a deviation from it for individual indicators of this diagnostic method can be detected on various scales. Based on the results obtained, it is possible to consider the issue of the condition of the fetus and adjust, if necessary, the management of pregnancy.
CTG is not a mandatory procedure, so the doctor may not refer the expectant mother to this study at all, however, if there are any concerns, the procedure must be carried out several times.
Features of the CTG procedure
This diagnostic method is used in the third trimester of pregnancy, usually from 32 weeks. Some doctors prescribe this study at 28 weeks, but the criteria for diagnosis are considered reliable from 32 weeks, since by this time the activity-rest cycle has stabilized in the fetus.
With the help of fetal CTG, the condition of the unborn child is assessed during natural physical activity. If the baby does not manifest itself in any way or sleeps at all, most likely, the procedure will be transferred or carried out again - there is nothing threatening in this. Since the method is absolutely harmless to the child, it can be carried out an infinite number of times.
If we consider the question, in what cases or when is CTG done during pregnancy, then it usually occurs in the following states:
- pathology of the placenta detected on ultrasound,
- suspicion of fetal growth retardation,
- possibility ,
- decreased fetal activity
- concomitant chronic diseases in pregnant women,
- or ,
- deviations in the last CTG,
- entanglement of the fetus, identified by ultrasound.
There is no special preparation before the procedure. However, every woman wants to be prepared for what awaits her. If appointed CTG during pregnancy, how to prepare to her, common sense will tell everyone. Since the study takes about 40-60 minutes, it is worth setting yourself up for a long pastime: take a light snack (apple, bread, chocolate), a blanket and a pillow for convenience. Be sure to go to the toilet before the procedure, otherwise you will have to endure for a long time, and the results will be unreliable.
The expectant mother will be laid on a couch or in a comfortable chair (you need to be in a state of reclining or lying on your side, you can’t lie on your back), a sensor will be attached to the stomach, information from which will go to the electronic unit. The doctor receives and studies all the data that is reflected in the curve. After the examination, the doctor writes a conclusion, which is given to the pregnant woman.
Fetal CTG results: transcript
The most important issue of this method remains decoding fetal CTG. There are several scales, the most popular are the 10-point Fisher scale and the 12-point Krebs scale. Usually, indicators are evaluated on both scales and two marks are written in the conclusion. It should be borne in mind that the data should not differ on different scales by more than three points.
Below we will dwell on the Fisher scale in more detail. After the CTG interpretation of the results goes according to the following parameters, which are individually evaluated from 0 to 2 points:
1. Basal rhythm (average between the values of the fetal heartbeat, not changing for 10 minutes or longer):
- less than 100 or more than 180 beats per minute - 0 points,
- from 100 to 119 beats per minute and from 161 to 180 beats per minute - 1 point,
- from 120 to 160 beats per minute - 2 points.
2. Variability (amplitude):
- less than 3 beats per minute - 0 points,
- from 3 to 5 beats per minute - 1 point,
- from 6 to 25 beats per minute - 2 points.
3. Variability (frequency per 1 minute):
- less than 3 - 0 points,
- from 3 to 5 - 1 point,
- more than 6 - 2 points.
4. Accelerations (an increase in the fetal heart rate by 15-20 beats per minute relative to the base frequency, which occurs in response to fetal movement, umbilical cord compression, uterine contraction) in 30 minutes:
- 0 (absence) - 0 points,
- 1-4 (periodic) - 1 point,
- from 5 and above (sporadic) - 2 points.
5. Decelerations (decrease in heart rate in response to movement or contraction of the uterus) in 30 minutes:
- severe atypical decelerations - 0 points,
- mild moderate decelerations - 1 point,
- absence or short shallow decelerations - 2 points.
To avoid subjectivity when deciphering fetal CTG data, in the modern world of medicine they are trying to create devices and computer programs that automate the decoding process as much as possible.
Normally, CTG during pregnancy on the Fisher scale ranges from 8 to 10 points. A result of 6-7 points is considered prepathological, and doctors are likely to prescribe a second examination. If the results of CTG are less than 6 points, this most likely means intrauterine fetal hypoxia and requires immediate hospitalization or urgent delivery.
Fetal Health Index (PSP)
According to the results of the graph obtained with CTG, doctors find the value of PSP (indicators of the state of the fetus), which during normal development is less than 1. If these values are in the range from 1 to 2, this may indicate the beginning of the onset of violations in the fetus. If the PSP value is greater than 3, this indicates a critical condition of the fetus. However, based only on these data, no decisions are made, the entire history of the pregnancy is considered. The reasons for the deviation of indicators can be not only problems in the development of the fetus (heart failure, anemia, hypoxia), but also some conditions in the expectant mother and child that are not associated with disorders (fever in a pregnant woman, sleep phase in a child).
It should be noted that the CTG method is auxiliary or additional, therefore, its results are based only in conjunction with other diagnostic data. This mainly affects small deviations from the norm, so it is not worth sounding the alarm in case of diagnosing results that are different from the norm before talking and discussing the results with a gynecologist.
What is cardiotocography? CTG is a simple and absolutely safe procedure that is performed in late pregnancy. But not every mother can decipher the results of the study, understand what the norm of fetal CTG should be and what this study gives.
Cardiotocograph is a device that is available in all maternity hospitals and antenatal clinics. With it, you can assess the state of health of the child after 32 weeks of pregnancywhen the baby establishes a connection between movements and heart rate, that is, his heart beats differently during rest and during active movements. The main parameter that is monitored on CTG is the child's heart rate. But with the help of CTG, other characteristics of the course of pregnancy can also be assessed: fetal hypoxia, malformations of the placenta, oligohydramnios and other anomalies. The sooner diseases and problems are identified, the more time doctors will have to take action and save the child's life. In fact, CTG is an extended cardiogram that monitors not only the baby's heartbeat, but also its movements and uterine contractions.
The first planned CTG is prescribed to a woman at 32 weeks. But if there is reason to suspect malformations, then this study can be carried out as early as 20 weeks. The study at this time of weekday is not so informative, but it accurately recognizes the disease and abnormal heart rhythm.
CTG is a non-stress test, absolutely safe for the mother and the baby, and does not have any harmful effects. This study shows both the basal rhythm of the baby's heart, and the state of his health, and the readiness of the uterus for childbirth. Only on CTG it is possible to distinguish training fights from real ones.
How is the fetal CTG procedure performed?
Despite the fact that fetal CTG is a non-stress test and a routine procedure that every pregnant woman does, many girls are afraid to go for the first time because they do not know what exactly will happen in the doctor's office. The procedure is absolutely painless and does not harm the baby. It is based on the Doppler effect, and works on the principle of ultrasound diagnostics. The device sends a beam of ultrasound into the body and captures its reflection. Based on how quickly the reflected waves return, the doctor makes inferences about the health of the baby, the speed of its heartbeat, the position and tone of the uterus, and many other things that can be diagnosed.
The study takes at least thirty minutes, so pregnant women are advised to eat and go to the toilet in advance. It is not recommended to eat immediately before the procedure, it is better to eat 1.5-2 hours before the doctor's appointment. It is forbidden to take sedatives and drink painkillers the day before CTG.
During the procedure, the woman lies on the couch in a comfortable, relaxed position. Gel is applied to her stomach and sensors are installed, one in the place where the baby's heartbeat is best heard, the second below, in the area of the fundus of the uterus. These sensors will record the baby's heart rate and the condition of the uterus, and based on the results, the doctor will assess the condition of the fetus and the health of the mother. In the hands of the woman will be a remote control with a button that must be pressed whenever the child moves. If the baby is sleeping, the doctor allows the mother to eat something sweet to increase blood sugar and “wake up” the little patient.
The device records all movements for at least 30 minutes in a row, and, as a rule, this is enough to catch all the states of the fetus, both sleep and wakefulness. In children in the womb, conditions change very quickly, and the doctor can assess his health and activity.
Deciphering fetal CTG during pregnancy
An assessment of the condition of the fetus is carried out by the doctor after the recording is completed. The main parameters that the doctor pays attention to:
- The basal rate, that is, the average value of the heart rate during the baby's sleep and during active movements. If the mother and child are calm, the frequency of contractions should be in the range of 110-160 beats per minute, during wakefulness the fetal pulse can reach 190 beats;
- The amplitude (variability) of the heart rate is the difference between the number of heartbeats in different periods of sleep and wakefulness of the child. Identical periods are compared in this parameter, and the difference between the number of heart beats can reach 20 beats per minute;
- Acceleration is displayed on the CTG chart as teeth. It means an increase in the number of baby's heart beats per minute and should appear about 1 time in 5-7 minutes or a little more often. The absence of acceleration within 15-20 minutes indicates the pathology of fetal development;
- Deceleration is another aspect of the fetal condition, a slowing of the heart rate. On the graph, decelerations are indicated by “dips” of the graph line, and normally this should not happen, but often the device does not record a slowdown in the heart rate, but the baby’s movement and uterine contraction. That is why a woman is given a remote control with a button that she presses every time the child moves inside: only in this way can the doctor separate the normal activity of the child from deceleration and signs of illness;
- The activity of the uterus is another parameter that is displayed on the record. The contraction of the uterus occurs in response to the movements of the child, and if this happens too often, there is a threat of early birth.
Normal readings can vary, but usually they are:
- Basal rhythm - 120-160 beats per minute;
- Variability - 5-25 beats / min;
- 1-4 accelerations in 15 minutes;
- Not a single deceleration;
- The activity of the uterus is less than 15%.
But not always the output of any indicator beyond the norm means a mandatory pathology of the development of the fetus and pregnancy. Both the human factor and technical errors cannot be ruled out. The mother might not have noticed or noted the movement of the baby in the womb, and a "failure" of deceleration appeared on the graph. The doctor in the antenatal clinic could incorrectly set the gestational age, and the norms have shifted. Even the CTG instrument may be faulty or out of calibration.
If the chart data is outside the normal range, there is no need to panic. An accurate diagnosis can only be made by a doctor who correctly reads the results of the CTG of the fetus during pregnancy, and not by the mother herself. But the excitement of a woman is harmful to the nervous system of the fetus.
If the results of the study cause doubts in the doctor, he will prescribe another study 2 hours after the first one to compare the indicators, or recommend using other diagnostic methods.
To make it easier to evaluate the results of the study, the Fisher scale is used, the points of which indicate the condition of the fetus during pregnancy. The child is considered healthy if the total score according to the results of the study is 8 or 10. If the score is 6 or 7, then this means that the baby is experiencing slight oxygen starvation, and the doctor will most likely monitor his condition further to correct the condition with medications or send the mother to the hospital. And if the score is less than 5, then the pregnancy is at risk, and the child may die. In this condition of the child, the mother is immediately hospitalized and, possibly, an emergency caesarean section is performed.
If the child receives little oxygen from the mother's blood, he will slowly develop hypoxia. This can happen if the mother smoked before pregnancy and smokes during it, if the child is tangled in the umbilical cord, and in several other pathological conditions. With hypoxia on CTG, the basal rhythm will be reduced, and the baby in the abdomen will move little and rarely.
Main pathologies:
- Silent CTG, that is, a static heartbeat curve, without accelerations and decelerations;
- Sinusoidal CTG speaks of hypoxia experienced by the child;
- The alternation of accelerations and decelerations is most often a sign of cord entanglement or clamping of the umbilical cord. In both cases, it is dangerous for the fetus.
Difference in CTG results in different weeks of pregnancy
Conventional studies and analyzes show different results in different periods of pregnancy. But the results of CTG during the period of carrying the child do not change much: there are radical differences between the heart rate of the fetus at 20 weeks and 36 weeks of pregnancy, but the difference between the results of the study at 34 and 35 weeks is almost not noticeable.
For longer periods, the child's heart beats a little slower than in the early ones. This is due to the maturation of the child's nervous system and the establishment of an intrauterine regimen, a change in the cycles of movement and rest. In addition, in the later stages, the amplitude of the heart rate is higher.
CTG is also removed during the onset of labor, when the mother's contractions begin. This study shows the contraction of the uterus and its condition and allows you to monitor the baby's heartbeat during childbirth, so that doctors can respond in time to a slowdown in the rhythm and save the baby's life.
Timely completion of all examinations is the key to the birth of a healthy child. Such a simple non-stress test as CTG will help keep the baby healthy and the mother's nerves, and if the pregnancy is not going too smoothly, it will help doctors notice this in time and take action. You can do CTG as in a free antenatal consultation, if there is reason to believe that the child in the womb is developing incorrectly, or in private clinics. This is a simple procedure, although it takes a lot of time, but it gives good accurate results. CTG is included in the third screening and is carried out not only in the middle of the term, but also just before the birth and even during them.
Despite the high accuracy of the study, it is impossible to draw a conclusion about malformations and developmental anomalies, looking only at the CTG recording. Only a doctor can make a decision and make a diagnosis, and only on the basis of several studies, such as a blood test, ultrasound, dopplerometry and CTG for several periods. Therefore, if the results of one study are not too good, this does not mean anything, and it is possible to diagnose a mother and child only after several days of observation.
Every mother remembers how many manipulations she had to go through for the healthy development of her baby.
Yes, there are many of them today. But today we will talk specifically about fetal CTG and its norms in pregnant women.
CTG is a method designed to diagnose ultrasound direction.
With its help, specialists can fully tell you what condition your baby is currently in, how he develops, and they receive this information precisely by studying the fetal heartbeat.
The method takes into account all aspects concerning the child. Since specialists measure the frequency of contractions of the fetal heart when it is at rest, they also note what changes take place during its direct movement.
In addition, an important indicator is his behavior and heartbeat at the time when the muscles of the uterus contract and when they are influenced by any external factors.
Why do you need to undergo a cardiotocogram?
KGT can fully provide the specialist with all the information regarding whether the baby has enough oxygen, to what extent there is water, there is not enough of it or, on the contrary, too much, and much more.
Ultrasound is performed shortly before the birth itself in order to be able to determine the state of the woman’s and baby’s body at the moment.
Therefore, it is determined whether the child can be born naturally. It is worth noting that this process must be carried out at least three times during the entire pregnancy.
But there are times when this amount is exceeded. An additional ultrasound can be performed for the following reasons: if a woman does not feel the baby’s direct movement within eight to twelve hours, or vice versa, the fetus has become too active.
In most cases, such “unhealthy” activity is evidence that there are any problems with the child.
Also, additional manipulations regarding CTG are carried out if:
- pregnant women experience excessive swelling;
- delayed pregnancy;
- there is polyhydramnios or oligohydramnios.
Basically, this feature occurs with gestosis, if, according to the results of urine tests, an excessive amount of protein was found in a pregnant woman, etc.
CTG research methodology
The fetal cardiotocogram is a process when sound waves reflected from moving objects produce the corresponding result, recording the parameters on a graphic tape.
This manipulation is performed using a special sensor that is able to capture high-frequency sound, or, more simply, using. By moving along the woman's abdomen in the area of the anterior wall, the specialist listens to the fetal heartbeat.
Reflecting from the fetal heart, the signal that has already been changed returns to the sensor. And after further processing on a computer with the help of special programs, they are displayed on a computer monitor.
Deciphering a cardiotocogram
Do not forget that only a doctor can correctly decipher the results of an ultrasound scan correctly.
The specialist compares all the data with the norms, thanks to which he determines the condition of your child. It is worth noting that the results obtained through manipulation should be compiled with other examinations in order to fully be able to accurately determine the condition of the fetus.
But if, after the doctor deciphered your data, for some reason you still have doubts, try to compare your results yourself with the norms for pregnant women provided in the table at the thirty-sixth week.
| Norm | Possible violations | Serious violations (threat to the life of the child) | |
| Number of points | 9-12 | 6-8 | 5 or more |
| BHR (bpm) | 119-160 at rest, 130-190 - in the active phase | 100-119 or more 160 | 100 and less or more than 180 |
| Variability | within 5-25 per minute | less than 5 or more than 25 | less than 5 or more than 25 |
| Rhythm | inducing or saltatory | monotonous or slightly undulating | monotonic or sinusoidal |
| Number of accelerations | 2 or more | less than 2 or absent | few or absent |
| Number of decelerations | No | shallow and short | late and variable |
| Fetal Health Index (PSP) | less than 0.8 | 1,05-2,0 | 2.01-3.0 and up |
Deciphering CTG: pathologies and norms
The results of the manipulation are on a paper tape and look like a broken line. It is this kind of curve that is an indicator of the baby's heartbeat.
And now let's clarify what indicators of such a check represent the norm of fetal KGT, so: the heart rate should not exceed one hundred and ten - one hundred and sixty beats per minute. This rate should be with a calm fetus.
But if your child, let's say, frolics in your tummy, then the indicators should be one hundred and thirty - one hundred and ninety beats per minute, but not higher. It is worth noting that even with such data, the heartbeat should be as calm and even as possible.
But there are naturally pathologies in which the indicators are from five to twenty-five beats per minute. This pathology is called deceleration.
It is a slow contraction of the baby's heart during optimal development, and the indicators for such a disease show no more than fifteen beats per minute.
Accelerated frequency of contractions of the heart muscle or degree of acceleration - a maximum of two in a period of thirty minutes with an immediate amplitude of about fifteen beats per minute. It is worth noting that for the fetus, the most optimal indicator is less than one.
Uterine activity or tokogram has no more than fifteen percent relative to the child's heart rate in a period of thirty seconds.
Any of the surveys we reviewed are rated against the application of a scale of one to ten. If the fetus develops well, then its indicator should be equal to the data from nine to twelve.
Can CTG detect contractions?
Contractions can be determined using a special test that is used to determine how the baby's heart behaves in relation to its movements.
With it, you can determine how closely at the moment the fetal vessels interact with the mother's placenta. If the level of exposure is high, then this indicates first of all an impending fight.
Fetal reactivity index with CTG
The reactivity index indicates the direct response of the baby's nervous system to external stimuli.
It should be noted that it quite closely correlates precisely with placental indicators regarding feto-placental insufficiency and the results of Dopplerography studies regarding fetal vessels.
The rate of CTG fetal movement per hour
First of all, it is worth noting that the fetus moves almost all the time, the only thing is that it can stop moving only while sleeping.
The average and normal indicator is at least two hundred movements per hour. Moreover, in the middle of pregnancy, this range increases three times. But the fetus grows, and there is less space for it, it is for this reason that its movements become less intense. And the closer the time to childbirth, the less and less he “frolics”.
How to determine hypoxia by CTG?
To determine hypoxia, it is necessary to take into account the factors inherent in it, namely:
- high or low rate of rhythm (basal);
- rhythmic monotony of BCHSS (the most dangerous is sinusoidal);
- low degree of BHR variability;
- a significant number of decelerations (if they are variable or late enough);
- the minimum number of accelerations, or their absence;
- non-stress and stress positive tests.
Errors during CTG assessment
Undoubtedly, there have been cases when the results of fetal CTG were erroneous. It is for this reason that it is impossible to consider specifically only the data of KGT separately from clinical studies.
Since ultrasound is just a kind of reflection of the nervous vegetative system of the baby on the load, it may be that the fetus will not have enough oxygen, but his body quickly adapted to the shortage and, therefore, a check through KGT simply will not detect any violations.
Attempts to create a device for recording fetal heart sounds - a kind of electrocardiogram for an unborn baby, led to the appearance of a cardiotocograph. Cardiotocography or CTG is the simultaneous recording of fetal heart rhythms and uterine contractions. I would like to note right away that at the moment fetal cardiotocography is the gold standard of the World Health Organization for assessing the condition of the fetus during pregnancy and the only objective criterion for such an assessment during childbirth.
The result of CTG recording - a cardiotocogram - is a graphic image in the form of two curves - fetal and uterine. The first is a record that reflects the change in heart rate every second. The second is similarly changing uterine activity. Scientists and practitioners around the world have created many evaluation tables and criteria for evaluating the received record. Below we will talk about how to make and decipher CTG.
How is fetal CTG done?
You can listen to the fetal heartbeat from a fairly early pregnancy - about 12-16 weeks, but on the recommendation of the World Health Organization, the record carries relevant information starting from the 28-30th week of pregnancy.
Modern CTG recording devices are small devices that can be easily carried and moved. The device is equipped with two sensors - uterine and fetal, as well as special elastic belts for fixing them on the belly of a pregnant woman. Both sensors are lubricated with a special gel before use to improve conductivity.
The uterine sensor is installed on the bottom of the uterus, and the second midwife leads along the belly of the expectant mother, trying to find the best point for listening to the fetal heartbeat. Most of the devices have a second fetal sensor to simultaneously record the heartbeat of twins. After finding the heartbeat point, the fetal sensor is fixed with a belt, and the patient assumes a comfortable position. You can record the fetal heartbeat while sitting, lying down or even standing. Also, a woman is offered a special button, which she must press with each movement of the fetus.
Recording time is very variable. The minimum recording time is 10 minutes, but can be up to an hour. The fact is that the intrauterine life of a child implies an alternation of periods of rest with periods of wakefulness. If the baby is sleeping at the time of recording, then the graph turns out to be uninformative - the so-called monotonous type of CTG. Such a record cannot be used to assess the condition of the fetus, so such a cardiotocogram must be rewritten after a while.
By the way, there is a little secret to "wake up" the baby and get a good record. 10-20 minutes before the procedure, the expectant mother needs to eat some sweets, take a quick walk in the fresh air or drink an oxygen cocktail.
CTG decoding rules
Of course, only a doctor is engaged in evaluating and decoding cardiotocograms. Self-assessment of the records is completely unacceptable, since in especially difficult cases even experienced doctors doubt the diagnosis for a long time.
As we have already mentioned, there are many evaluation criteria for deciphering CTG. I would like to note that domestic scientists are also involved in the creation of such criteria - Savelyeva, Voskresensky, Gerasimovich and others. At the moment, two rating scales are widely used - Dose-Redman and Fisher. Despite the variety of scales and tables, they all mainly use several basic cardiotocogram indicators:
- Fetal heart rate. Normally, this figure ranges from 120-160 beats per minute.
- The presence of special indicators of the curve itself - accelerations and decelerations. These are special surges and drops in the fetal cardiac activity, by the presence of which it is possible to predict the state of the fetus with a high degree of probability.
- The frequency of oscillations, that is, how varied the rhythm curve is.
- The reaction of the child's cardiac activity to movements and uterine contractions. This indicator is extremely valuable in childbirth.
- Uterine activity - the presence of contractions, their frequency, duration and strength.
Assessment of CTG according to the Dawes-Redman criteria
The Dawes-Redman criteria are embedded in most CTG devices with the ability to automatically analyze cardiotocograms, that is, at the end of the recording, the cardiotocograph displays a column of numbers:
- The number of accelerations and decelerations.
- Fetal activity - fetal movements per hour.
- Time of CTG recording.
- The average fetal heart rate, as well as peak - its minimum and maximum values for the recording period.
- The sum of all these is the so-calledSTV-short-teamvariation or heart rate variability.
It is STV that is the criterion for assessing the condition of the fetus. It is important to understand that scale Dose-Redman is relevant only for the evaluation of a pregnant woman, but not relevant in the period of childbirth. Here is a gradation of variability values:
- For healthy fetuses, the limits of normal variability will be 6-9 ms.
- STV values of 5-3 ms are borderline and should definitely be assessed by doctors as suspicious.
- STV from 2.6 to 3 ms means a high risk of fetal pathology and requires constant monitoring and fairly intensive treatment.
- STV less than 2.6 is estimated as preterminal, that is, the risk of fetal death in the next three days is about 80%.
- There is no upper limit of normal for STV in utero. This means that variability above 9 ms while maintaining other indicators (accelerations, basal rate, etc.) is normal.
Automatic assessment of cardiotocograms necessarily takes into account the duration of pregnancy. That is why the decoding of the CTG of the fetus at 36 weeks of pregnancy will be slightly different from that at 28 weeks.
CTG assessment according to Fisher's criteria
The Fisher scale is used for the so-called manual assessment of cardiotocograms. This scale is used in childbirth. There is a special table for evaluating each of the indicators in points: basal rhythm, the presence of accelerations and decelerations, the amplitude and frequency of oscillations. The sum of points received is evaluated as a result:
- The normal state of the fetus is 8-10 points. Such numbers indicate a normal heart rate and an adequate supply of oxygen to the fetus.
- Doubtful condition of the fetus - 5-7 points. This may indicate oxygen starvation of the fetus - hypoxia. Such indicators require close attention of the doctor. Additional studies and re-recording of CTG during the day are recommended.
- Unsatisfactory condition of the fetus - 0-4 points. In this case, fetal hypoxia can become fatal, therefore, active medical action is required, up to urgent delivery by caesarean section or the imposition of a vacuum extractor.
What does CTG show
As we have already found out, cardiotocography evaluates the heart rate of an unborn baby, its physical activity and uterine contractility. Based on this, we list the conditions that can be tracked and suspected using CTG.
- Fetal hypoxia - oxygen starvation. This situation occurs for a variety of reasons: placental insufficiency, increased uterine tone, inflammatory processes in the uterine cavity, high blood pressure and diseases of the mother's cardiovascular system, and much more. Cardiotocography will not show the cause of hypoxia, but will only establish the fact of its presence.
- Anomalies of the fetal heart rate. For example, a constant increase in the fetal heart rate - tachycardia - may indicate pathology of the fetal heart, fetal anemia, Rhesus conflict and other alarming conditions.
- Threatened or started premature birth. In this case, recording of uterine activity comes to the rescue. Frequent and regular contractions up to 37 weeks of gestation may indicate the threat of preterm labor.
- Anomalies of labor activity. CTG shows irregular, rare or weak contractions in childbirth, as well as the reaction of the birth process to the administration of drugs - oxytocin or prostaglandins.
What to do if the result of CTG is bad
We emphasize once again that the obstetrician-gynecologist should deal with the decoding of CTG. It is the doctor who, having evaluated all the indicators of the cardiotocogram, decides whether its result is satisfactory. Further actions of the doctor will depend on how bad the result is:
- Repeated recording of CTG during the day, as well as CTG monitoring, that is, daily recording for several days in a row.
- Ultrasound examination of the fetus with dopplerometry - measurement of blood flow in the uterus, placenta and vessels of the fetus.
- If the results of the studies establish mild or moderate fetal hypoxia, then the patient is prescribed drugs that improve fetal and uterine blood flow - antispasmodics, pentoxifylline, curatil, actovegin and others.
- With mild degrees of hypoxia, hyperbaric oxygenation is indicated. To do this, the pregnant woman is placed in a special chamber, where an increased atmospheric pressure is created, which facilitates the absorption of oxygen by the tissues.
- It is also important to eliminate conditions that cause hypoxia from the outside - a sedentary lifestyle of a pregnant woman, adjust the hemoglobin level, blood pressure, and find out if the pregnant woman has a Rh conflict with the fetus.
- In severe cases of hypoxia, immediate hospitalization of the patient to the hospital is indicated and, most often, early delivery in the name of saving the child.
It is very important in case of certain issues with CTG to carefully follow the doctor's recommendations, since this method is very informative and really accurately predicts the well-being of the fetus.
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 fetal biorhythms 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:
|
Complicated pregnancy:
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Diseases in the fetus, identified by ultrasound examination:
|
Serious illness in a pregnant woman:
|
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 Doppler.
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.