Analysis of ktt. Planned appointment of the survey. When to do CTG

Cardiotocography is an important study of a still very small human heart and helps to identify pathologies at an early stage, to begin to correct problems. What does fetal CTG show, how to decipher the tests and how to determine if the baby's condition is normal?

What is CTG in pregnant women

CTG during pregnancy is a method for assessing uterine contractions and the baby's heartbeat, which is still developing in utero. The study is important because it allows you to identify deviations from the norm at an early stage. Doctors, using an apparatus for listening to the fetal heartbeat, determine this procedure as mandatory for the expectant mother, like ultrasound and dopplerometry.

A check with a cardiotocograph is prescribed, starting from the 30th week, only women who have indications for CTG during pregnancy are examined before this period. The procedure confirms whether the baby is healthy, whether there are dangerous pathologies for the pregnant mother or baby. If the specialist has identified any anomalies, then the doctor from the antenatal clinic should correct the process of pregnancy management, and in some cases, therapeutic measures are taken. These diseases include:

• hypoxia in a child;
• oligohydramnios or polyhydramnios;
• functional disorders in the placenta;
• fetal tachycardia;
• disorders of the cardiovascular system.

When is fetal cardiotocography indicated?

Heartbeat and uterine contractions on CTG are checked in such cases:

1. If the condition of the baby and mother is normal, then CTG is done once during a normal pregnancy. If the recording recorded pathological changes, a re-recording is assigned. The procedure is carried out from the 30th week of pregnancy.
2. If past pregnancies were unfavorable (death of a child in utero, genetic and chromosomal disorders).
3. Feelings of the mother that something is wrong with the child. Every mother already knows how the baby behaves in the womb. If there is a change in the regimen, the activity of the child, then the pregnant woman should pay attention to this.
4. With the course of acute diseases (flu, tonsillitis, SARS), chronic infections in a pregnant woman and outpatient or inpatient treatment.
5. With gestosis in a pregnant woman.
6. If a woman is subject to bad habits: during pregnancy she smokes, takes alcohol or drugs.
7. If the pregnant woman suffers from chronic diseases of the internal organs.
8. If the pregnancy is delayed.

At what time do fetal CTG

If the pregnancy proceeds normally, there are no complications, then CTG is recommended to take place in the third trimester 1-2 times. If during the first studies some pathological changes are detected, then an additional examination procedure is prescribed. A check-up procedure is carried out during childbirth in order to comprehensively assess the general condition of the baby. During the contraction, a CTG record is kept, according to which the condition of the child is assessed, and decisions are made on further delivery. This is especially true for babies with cord entanglement.

Why do CTG pregnant

Using only this research method, one cannot be sure of the reliability of the diagnosis. The condition of the baby inside the mother can change due to the medication taken by the woman, depending on the food taken, mood, reactions to external stimuli. CTG helps to identify such pathologies during pregnancy:

1. Umbilical cord wrap. This condition is dangerous by a violation of the supply of oxygen from the mother to the child. Blood flow not restored in time can lead to a serious condition.
2. Irregularity of the fetal heartbeat. This is a signal that there are anomalies of the heart.
3. Hypoxia. During the study, small signs of pathology will be noticeable.

The procedure is carried out quickly, which gives real chances to assess the condition of the child even during childbirth, to resolve labor activity as correctly as possible. If the mother has pathologies that affect the fetus, then the woman is sent to the hospital, observed and recorded daily. If abnormalities are detected, the expectant mother is examined for ultrasound and dopplerography is performed. If the diagnosis is confirmed, then treatment is prescribed, in which CTG is done 1-2 times daily to assess the effectiveness of the treatment, monitor the condition of the fetus.

How is CTG performed for pregnant women and during childbirth

The procedure is safe, but you need to prepare. A woman should sleep well, not experience nervous breakdowns, stress, be completely calm. In order for the study to give the most accurate result, the child must be active. To do this, the mother needs to eat something sweet before the procedure, preferably a chocolate bar. The woman takes a lying or reclining position, is conveniently located. A pressure sensor (load cell) and an ultrasonic sensor are attached to the abdomen. The first controls uterine contractions, the second controls the fetal heartbeat. The recording lasts 30-60 minutes.

Deciphering fetal CTG

The Fisher way of explaining the results is the most used and takes into account the following parameters:

1. The average heart rate is the norm from 119 to 159 beats in 60 seconds.
2. Fluctuations in the frequency of heart contractions - the norm is from 5 to 25 beats.
3. The frequency of changes is the normal state with 6-10 teeth on the curve.
4. An increase in the child's heartbeat (acceleration) - within 10 minutes at least 2 accelerations.
5. Deceleration is the reverse process of the previous one, in the absence of pathology it should not be.

Each attribute is rated on a scale from 0 to 2. How many points should be given for each? The indicator of the norm - 2 points, a slight deviation up or down - 1 point, critical inconsistencies - 0 points. The transcript of the survey looks like this:

• 4 or less points - the index shows an acute condition, the doctor must prescribe treatment, observe the patient regularly;
• 5-7 points - an indicator of oxygen starvation;
• 8-10 - the child is fine.

Video: what is fetal CTG during pregnancy

CTG - cardiotography - a completely safe method of monitoring the condition of the unborn baby. Without any discomfort for the baby, you can get the necessary information about his heart rate and contractions of the mother's uterus.

CTG is usually prescribed after the 26th week of pregnancy, since before that it is difficult to unambiguously decipher the data obtained. Without fail, you will be sent for CTG twice in the third trimester of pregnancy. If something alerts the doctor, he will prescribe a second (or additional) study of CTG.

How is the CTG procedure performed?

The procedure takes quite a long time - 40-60 minutes. Mom is laid on a couch (sometimes they offer a comfortable chair), a sensor is attached to the stomach, which sends information about the heartbeat and uterine contractions to the electronic unit. All data is graphically displayed on a curve, which is then studied by the doctor.

How the results are evaluated: CTG scores

After the study, the doctor examines the tape with indications (curves) and writes a conclusion.
When CTG evaluate:
Basal Rhythm (BHR or HR)- average heart rate. Norm: 110-160 beats per minute in a calm state of the fetus (130-190 when moving).
Rhythm variability— average height of deviations from heart rate. Norm: deviation height - 5-25 beats / min.
Accelerations (accelerations)- acceleration of heart rate (on the graph they look like high teeth). Norm: 2 or more accelerations in 10 minutes.
Decelerations (Decelerations)- deceleration of heart rate (they look like significant depressions on the graph). Normal: absent or shallow and very short.
Tokogram - uterine activity. Norm: uterine contraction is not more than 15% of BHR, duration - from 30 sec.

To decipher CTG, a 10-point system is used, where each of the six criteria (basal rhythm, variability (amplitude), variability (quantity), acceleration, deceleration, fetal movement) is estimated from 0 to 2 points.

Assessment of the condition of the fetus by points:

from 9 to 12 points - the fetal condition is normal, further observation is recommended;
from 6 to 8 points - oxygen starvation (hypoxia) without emergency threats, a repeat of the CTG procedure is necessary;
5 points or less - severe oxygen starvation, emergency delivery is necessary.

With many studies, a woman meets for the first time, some diagnostic procedures are not familiar to her, therefore, the expectant mother is alarmed, they make her doubt that everything is in order with her and the baby. One gynecologist said that for the first time a young woman came to the CTG procedure all in tears, with the full conviction that once an examination was scheduled, then a pathology was suspected ... a specific purpose. So what is this procedure - ktg? Why is she appointed? Let's look into these issues in detail.

1 Why appoint KTG?

Cardiotocography (CTG) is a research method that is based on the analysis of the variability of the fetal heart rate (in medical terminology, the fetus is the unborn baby from the eighth week of intrauterine development until the moment of birth). With fetal CTG, the frequency of the baby's movements and the contractile activity of the uterus are also recorded. CTG is carried out using Doppler-based cardiac monitors, which record changes in the intervals between individual cycles of the fetal cardiac activity.

Analyzing the results of CTG, one can assess the functional state, frequency of fetal movements, understand whether he is comfortable, whether there is enough oxygen, the frequency and strength of uterine contractions. Thanks to the fetal CTG procedure, the doctor can timely notice deviations in the course of pregnancy and provide the necessary assistance to the pregnant woman and the unborn baby in time. Fetal CTG is prescribed both for prophylactic purposes from 30-32 weeks of pregnancy to all women, and for medical reasons (in this case, the terms may be different).

Usually, if the pregnancy is going well, a woman undergoes a CT scan of the fetus in the 3rd trimester at least twice, if there are indications (aggravated obstetric history, entanglement of the umbilical cord, scars on the uterus, placental insufficiency, polyhydramnios or oligohydramnios, features of the development of the fetal cardiovascular system) - more often according to doctor's instructions. With planned hospitalization a few weeks before childbirth, women undergo daily fetal CTG, this procedure becomes familiar to them, and most are looking forward to it, because it shows the heartbeat of their crumbs, some devices reproduce the sound of the baby's beating heart.

2 How is the procedure?

Fetal CTG is completely painless for both the expectant mother and her future baby. A woman occupies a comfortable position half-sitting or reclining on her back or on her side; lying down is not recommended for the procedure, because. in the supine position, compression of the inferior vena cava may occur and the recording results will be distorted. Two sensors connected to the monitor are attached to the belly of the pregnant woman. One sensor captures the fetal heartbeat, and the second - uterine contractions.

Older heart monitors have another fetal movement sensor with a button that is placed in the woman's hands and she has to press the button every time she feels her baby move. New modern devices do not have such a device. The procedure lasts 30-35 minutes, so before it is carried out, the woman is recommended to get enough sleep, go to the toilet. If the child during the CTG is not active and sleeps in the mother's stomach, the procedure will not be informative.

To increase the activity of the fetus, a woman in the absence of allergies is recommended to eat one or two slices of chocolate. It is not recommended for a woman to worry, get upset, worry, these factors can contribute to the distortion of the results. The fetal CTG procedure is completely harmless, painless, has no contraindications and side effects from both the mother and the fetus. Also, fetal CTG can be carried out directly in childbirth in order to understand how the baby feels.

3 How does the doctor "read" CTG?

Deciphering the CTG of the fetus is the prerogative of gynecologists, but every woman can have an idea of ​​\u200b\u200bwhat the results of the CTG mean, what the indicators are and whether they are the norm of the CTG. As a rule, by the 32nd week, the child’s cardiac reflex has already been formed, and for every movement he has a reaction of the cardiovascular system in the form of an increase in heart rate. Sensors record these indicators, which are recorded as a curve on a tape - a cardiotocogram. The gynecologist evaluates the curve in points from 1 to 10. According to this assessment, it can be concluded how the child feels in utero, how much his body, including the cardiovascular system, is provided with oxygen, whether there is fetal hypoxia.

4 What parameters does the doctor evaluate?

It is difficult for an unprepared person to say what a cardiotocogram means. It shows a continuous line and teeth, directed mainly upwards, less often downwards. But how to decipher these indicators? On the cardiotocogram of the fetus, the doctor evaluates the following indicators:

• The basal rate is the arithmetic mean of the fetal heart rate over 10 minutes. The normal basal rate is 110-160 beats per minute.
• basal rate variability (amplitude and frequency). On the film, variability stands out in the form of teeth and teeth. Sometimes such jumps scare a woman, in fact, this is even good. The ktg line should not be flat.
• acceleration is an increase in heart rate of 15 beats or more within 15 seconds. On ktg they look like teeth pointing upwards. Occur during fetal movement. Normally, accelerations are 2-3 or more in 10 minutes.
• deceleration is a slowing of the heart rate by 15 or more within 15 seconds in response to a contraction or with uterine activity. On ktg they look like teeth pointing down. If decelerations are rare, shallow, after which a normal basal rhythm is quickly restored, then there is no cause for concern. The physician should be alerted by frequent, high-amplitude decreases in heart rate on the film.

For each of the four indicators, the doctor assigns points, from 0 to 2. And then, summing up the result, he receives the final number of points, which gives an assessment of the condition of the fetus and its cardiac activity.

Fisher's rating scale is as follows:

• 8-10 points - the norm of fetal CT, the child's condition is good. The mother-to-be has no reason to worry.
• 6-7 points - a borderline condition that requires repeating the procedure and reinforcing the results with additional research methods (ultrasound with Doppler ultrasound).
• 5 points and below - a threatening condition of the fetus. 1-2 points of CTG during pregnancy are critical points, they require the patient to be hospitalized as soon as possible in a hospital and the issue of further management of pregnancy should be resolved.

5 Normal results

Normal CTG indicators are a concept that fits into very specific criteria, namely: the basal rhythm should be 119-160 beats per minute, the deviation amplitude is 7-25 beats per minute, at least 2 accelerations in 10 minutes, the absence decelerations or mild decreases in heart rate. These are normal indicators. But you should always remember that one record does not make a diagnosis, and small deviations from the norm are not a pathology. The graph data may vary depending on whether the baby is sleeping or awake, is in a calm or active state, and also on which week of pregnancy the examination is performed.

6 indicators to watch out for

The doctor should be alerted to the results of CTG, which have significant deviations from the normal range: if the basal rhythm is less than 110 or more than 190 beats per minute. A low frequency of 110 or less indicates a slowing of the heartbeat in the fetus, and a high one, on the contrary, indicates a pronounced increase. Both can indicate fetal hypoxia, oxygen starvation. A basal rhythm over 190 and under 110 is scored as 0 points. It is also not very good when there are no accelerations in response to the movement of the fetus. This may indicate tension and exhaustion of the fetal compensatory reactions, immaturity of the cardiac reflex.

Deep and frequent decelerations always alert the doctor, they may indicate a violation of placental blood flow and require careful study. A monotonically variable basal rhythm or an amplitude of less than 10 or more than 25 beats also raises questions for the doctor. If the decoding of fetal CTG gives a dubious result of 6-7 points, it is necessary to repeat the study and supplement it with other examination methods to determine the reasons that led to this result. But do not immediately panic, it can only harm the condition of the unborn baby.

The reason for the immediate hospitalization of a pregnant woman is threatening indicators on the Fisher scale 1 point - 5 points.

7 I was not prescribed CTG?

You are pregnant, you feel how your baby is growing, kicking, and your meeting with him will take place very soon, but the doctor has not yet prescribed CTG for you? Why? Perhaps your pregnancy is going well, and its term has not come to 32 weeks, you have no indications for an earlier pregnancy. This is just a reason for joy, and in no way a reason for concern.

8 Is it possible to diagnose by CTG?

No. If any deviations as a result of the procedure were identified, the doctor will refer you to other examinations (laboratory, instrumental). And already in a comprehensive assessment, taking into account the data of all studies, a diagnosis will be made, the results of deciphering the CTG of the fetus will be confirmed or refuted.

Cardiotocography (CTG)- this is a method for assessing the condition of the fetus, which consists in recording and analyzing the frequency of its heartbeat at rest, movement, with uterine contractions and exposure to various environmental factors . This study allows you to identify signs of hypoxia (oxygen deficiency) of the fetus, which significantly reduces its ability to adapt to changing environmental conditions that affect it through the mother's body. Hypoxia also leads to a delay in the growth and development of the fetus, increases the likelihood of various disorders during childbirth and the early postpartum period.

additionally A cardiotocogram is a simultaneous recording of uterine contractions and fetal cardiac activity. This allows a comprehensive assessment of the reactivity (the ability to change heart rate under the influence of various factors) of the fetal cardiac activity.

According to the method of obtaining information, two types of CTG are distinguished:

• indirect (external);
• direct (internal).

With external CTG, the fetal cardiac activity and the force of uterine contraction are determined non-invasively (without breaking the integrity of the skin) through the anterior abdominal wall of the woman's abdomen. To register the heartbeat during CTG, ultrasonic is used, and for measuring tensometric (pressure sensor for measuring the strength and spontaneous contractions of the uterus) sensors superimposed on the belly of a pregnant woman. The indirect method has practically no contraindications and does not cause any complications; it is used both during pregnancy (antenatal CTG) and in childbirth (intranatal CTG).

Internal CTG is used extremely rarely and only in childbirth. To register the heartbeat, an ECG electrode is used, which is attached to the skin of the fetal head, and to measure intrauterine pressure, a strain gauge or catheter into the uterine cavity is used.

When is CTG done?

CTG can be used already starting from the 28th-30th week of pregnancy, however, it is possible to obtain a high-quality record for the correct characterization of the fetal condition only with, since at this time the activity-rest cycle is established, when the fetal motor activity is regularly replaced by rest modes. On average, the duration of fetal sleep is 30 minutes, this must be taken into account when conducting and evaluating the results of the study in order to avoid erroneous conclusions.

In the normal course of pregnancy, CTG is usually performed no more than once a week (on average, 1 time in 10 days). With a complicated pregnancy, but favorable results of previous studies, CTG is performed at intervals of 5-7 days, and with any changes in the woman's condition. In case of fetal hypoxia, the study is carried out daily or every other day until the fetal condition normalizes or until a decision is made on the need for delivery.

Information In the normal course of labor, repeated CTG recordings are performed every 3 hours in the first stage of labor, in the presence of complications, the frequency of studies is determined by the doctor. The second stage of labor is desirable to conduct under continuous monitor control.

The optimal time of day for conducting a cardiotocographic study of the fetus, when its biophysical activity is most pronounced, is from 9 00 to 14 00 and from 19 00 to 24 00 hours. It is undesirable to carry out CTG on an empty stomach or within 1.5-2 hours after a meal, as well as during or within an hour after the administration of glucose. If for some reason the recording time is not observed, and at the same time deviations from the normal nature of heart rate variability are detected, a second study must be carried out in compliance with this rule. This is due to the fact that the body of the fetus is directly dependent on the mother, and a change in the level of glucose in her blood can affect its motor activity and ability to respond to external stimuli.

How is cardiotocography performed?

With an indirect method, cardiotocography is performed in the position of a woman on her left side or in a sitting position. The choice of position depends on the position of the woman in which the fetal heartbeat is heard as well as possible. Recording in the supine position is undesirable due to the possibility of squeezing the main blood vessels by the uterus and, as a result, obtaining unsatisfactory test data. An external ultrasonic sensor is placed on the anterior abdominal wall of a woman in the place where the fetal heart sounds are best audible, and a strain gauge sensor is placed in the area of ​​the right corner of the uterus. The average duration of CTG recording is 40 minutes, however, if satisfactory data are obtained, the examination time can be reduced to 15-20 minutes. When conducting functional tests, there is a baseline recording (10 minutes) plus the time of the test.

During childbirth, CTG is performed for at least 20 minutes and / or for 5 contractions. With changes in the condition of the woman in labor and the fetus, the duration of the study is determined by the doctor.

According to the method of obtaining information, cardiotocography is divided into two types and includes the following varieties:

• Non-stress cardiotocography

1. Non-stress test - a recording of the fetal heart activity in the natural conditions of its habitat is carried out with the registration of movements and marks about them on the cardiotocogram.
2. Fetal movements are a method for determining the motor activity of the fetus indirectly through changes in the tone of the uterus. Used when there is no motion detection sensor.

• Stress cardiotocography (functional tests) used for unsatisfactory results of a non-stress test for additional diagnostics:

Tests that simulate the birth process:

• Oxytocin stress test. They induce contractions by intravenous administration of an oxytocin solution and observe the reaction of the fetal heartbeat to the resulting uterine contractions.
• Mammary test (nipple stimulation test, endogenous stress test). Contractions are caused by irritation of the mammary glands by twisting the nipples with your fingers. Irritation of the nipples is produced by the pregnant woman herself before the onset of contractions, which is judged by the readings of the cardiotocograph. This method is safer than the previous one and has fewer contraindications.

Directly affecting the fetus:

• Acoustic test - determination of the reaction of the fetal cardiac activity in response to a sound stimulus.
• Atropine test (currently not used).
• Palpation of the fetus - produce a limited displacement of the presenting part of the fetus (head or pelvic end) above the entrance to the small pelvis.

Functional trials that change the parameters of uterine and fetal blood flow (now practically not used)

Reflex tests- the reaction of the fetal cardiac activity in response to an irritant, which is due to neuro-reflex connections between the mother's body and the fetus (rarely used).

CTG decoding

To characterize the condition of the fetus using cardiotocograms, the following indicators are used:

• heart rate (HR);
• basal heart rate- this is the heart rate that persists for 10 minutes and in the intervals between contractions;
• variability(change) basal rate;
• acceleration- short-term acceleration of heart rate for 15 seconds or more by 15 or more beats per minute;
• deceleration- deceleration of the heart rate by more than 15 beats per minute for 15 seconds or more;

Indicators of normal CTG:

• basal rhythm at 120-160 beats / min;
• amplitude of basal rhythm variability – 5-25 beats/min;
• decelerations are absent or very rare shallow and very short decelerations are noted.
• 2 accelerations and more are recorded during 10 minutes of recording.

Evaluation of CTG by points

To simplify the interpretation of antenatal CTG data, a scoring system was proposed.

Table 1. Scale for assessing fetal cardiac activity during pregnancy [Savel'eva G.M., 1984]

Grade 8-10 points indicates the normal state of the fetus.

5-7 points indicates the initial signs of hypoxia, repeated non-stress CTG is required during the day, if the result has not changed, then an oxytocin or mammary test is necessary, the use of additional research methods: (a method based on measuring blood flow in the vessels of the fetus and placenta), assessment of the biophysical profile fetus (a set of parameters of the state of the fetus determined using).

4 points or less- for serious changes in the condition of the fetus. It is necessary to immediately make a decision on emergency delivery or intensive care of a woman to stabilize her condition and the condition of the fetus.

Important Cardiotocography is an important and integral method for diagnosing the condition of the fetus, but the value of the method increases when the results are combined with data from other research methods and a general examination of the pregnant woman. Only on the basis of a comprehensive assessment can a conclusion be made about the necessary treatment or method of delivery.