RU2688022C1 - Method for determining cardiocotography type of human fetus - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, specifically to obstetrics. Foetal heart rhythm is recorded and significant parameters are isolated and analysed on curve of 30-minute recording segment. When registering four or more consecutive sections with continuous increase or decrease in the range of frequency fluctuations of foetus (FFF) and / or when recording the predominance of growth or reduction of FFF on 2 or more oppositely directed sections of the recording curve, the number of growth pairs and the number of subsequent reduction pairs are set on these sections. If the number of growth pairs exceeds the normal type of cardiocotography. When recording on a fragment of a recording curve of 2 consecutive pairs of oppositely directed sections with more than double difference in the span of oscillations and the transition point between them, coinciding with the transition point between their largest sections, the pathological cardiocotography type is stated. In the absence of signs of normal and pathological types of cardiocotography a suspicious cardiocotography type is established.

EFFECT: method increases accuracy of determining the type of cardiocotography by introducing uniformity and simplifying evaluation of its significant parameters.

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Description

The present invention relates to medicine, namely to obstetrics and can be used to diagnose the condition of the human fetus according to its cardiotogram.

Cardiotocography is known to be a method of assessing the condition of the fetus, consisting in recording and analyzing the frequency of its heartbeat at rest, in motion, with contractions of the uterus and the effects of various environmental factors. This study allows you to identify signs of hypoxia. Such electronic monitoring of the fetal heartbeat is carried out periodically during pregnancy, as well as periodically and continuously in labor.

The determination of the type of cardiotocogram (CTG) of the fetus includes the analysis of such parameters of the fetal heart rate as the baseline and its variability, the presence and number of accelerations and decelerations. On their basis, three types of cardiotogram are distinguished: normal, suspicious or suspicious, and pathological.

There is a method of determining the type of cardiotogram, including recording of the fetal heart rate, the selection and analysis of relevant parameters on the recording curve of a 30-minute segment. To do this, in the place of the best listening of the fetal heartbeat, on the anterior abdominal wall of the mother, an ultrasonic transducer is applied and fixed with rubber tapes and the fetal heart rate is recorded. On any 10-minute segment of the 30-minute fragment of the FSS recording curve, the baseline (BL) is distinguished - the average value of both the highest and the lowest FSS rounded to the nearest frequency level in the direction of its increase. Normocardia is determined with BL from 110 to 160 beats per minute, tachycardia with BL is higher than 160 beats / min, bradycardia with BL is lower than 110 beats / min. Then, baseline variability (VBL) is selected and the absence (0 beats / min), low (1 to 5 beats / min), normal (6 to 25 beats / min) and high (25 beats / min and above) VBL are determined . Next, establish the presence of acceleration or variable deceleration (VD) of PSP, for which the achievement of the top or bottom, respectively, should be carried out in less than 30 seconds. As for accelerations in the period of 32 weeks of pregnancy and above, and for VD, the severity of deviations from BL and the duration are 15 beats / min and 15 seconds, respectively. The height and duration of accelerations up to 32 weeks is 10 beats / min and 10 seconds, respectively. For early decelerations (RD) and late decelerations (PD), a connection with contractions can be traced, both synchronous development with them and those beginning with a peak of contraction, while the time to reach the depression of decelerations is more than 30 seconds. The duration of prolonged accelerations and decelerations must be more than 2 and less than 10 minutes, and for their duration of 10 minutes or more, a new BC will be installed. Then, the average frequency of contractions (ES) over three 10-minute intervals is estimated and in case of an emergency, normysystalline is set to 5 or less, and in an emergency more than 5, uterine tachysystole is established.

With BL from 110 to 160 beats per minute, VBL from 6 to 25 beats per minute, the presence or absence of accelerations, and the absence of recurring RD, PD and VD determine the first category or normal type of CTG.

In the absence of VBL with repeated PD or VD, or BL less than 110 beats per minute, as well as with a sinusoid-like form of the recording curve (CG), category III CTG is established - a pathological type CTG.

In the absence of traits characterizing the I and III categories, CTG is classified as category II — a dubious type (Intrapartum fetal heart rate monitoring: nomenclature, interpretation, and general management principles. ACOG Practice Bulletin No. 106. American College of Obstetricians and Gynecologists // Obstet Gynecol. - 2009. - T. 114. - P. 192-202).

The weakness of this method includes the insufficient accuracy of determining the type of CTG associated with the subjectivity of estimating significant parameters, which is due to different variants of their isolation and interpretation, as well as the variability of PTP and the inconsistency of the selection of the key parameter CTG - baseline (BL), relative to which and evaluate the acceleration and deceleration of PSP, because BL is installed in the absence of a record of accelerations and decelerations on the curve, although at the same time, it itself is a visual support for their determination.

Also to the disadvantages of this method include the need to highlight five intermediate signs of CTG: BL, VBL, acceleration, deceleration, ES, each of which is divided into several levels.

In addition, the disadvantages of this method include the inability to determine the type of CTG when recording PSP less than 10 minutes due to the lack of conditions for the selection of the main parameters.

The closest in technical essence to the present invention is a method for determining the type of cardiotocogram (CTG) of a human fetus, including recording a heart rhythm, isolating and analyzing significant parameters on the recording curve of a 30-minute segment.

The known method, as well as a similar one, involves the imposition and fixation of a transducer on the region of the best hearing of the fetal heartbeat on the anterior abdominal wall of the mother. BL and its levels are also distinguished; they determine the variability, but not only BL, but also the variability of decelerations (from 0 to 5 beats / min - low, from 5 to 25 - normal, above 25 - high). At the same time, the presence or absence of accelerations and decelerations of PSP is established, their forms are distinguished (RD, PD, VD, prolonged (PLD).

With BL from 110 to 160 beats per minute, VBL from 5 to 25 beats per minute, the presence or absence of acceleration, and the absence of repeated decelerations establish the normal type of CTG. At the same time, in the presence of accelerations and repeated decelerations, the normal type of CTG is also determined.

Pathological type CTG is established when one or more of the following symptoms are detected: BL less than 100 beats per minute, VBL less than 5 and more than 25 beats per minute, sinusoidal form of CG, late decelerations (PD) or PLD associated with more than 50% of contractions in for more than 30 minutes with VBL 5 or more beats per minute or for 20 minutes with VBL less than 5 beats per minute, the only PDD more than 5 minutes.

In the absence of at least one sign of a normal type of CTG, but without signs of a pathological type of CTG, it is referred to as suspicious (Ayres-de-Campos D., Spong C.Y., Chandraharan E. FIGO consensus guidelines on intrapartum fetal monitoring: Cardiotocography / / International Journal of Gynecology & Obstetrics. - 2015. - T. 131. - No. 1. - C. 13-24).

The disadvantages of this method, as well as the analogous one, include the low accuracy and specificity of determining the type of CTG associated with a disagreement in the assessment of its significant parameters. So, by the same doctor, but at different time intervals, as well as by different doctors, especially when identifying and evaluating slowdowns, variability, and when classifying CTG type as doubtful and pathological, the determined short-circuit parameters initially rated as normal or doubtful , with a retrospective assessment (in cases with a known adverse outcome of labor for a child) became pathological.

In addition, the types of CTG determined by this method have low specificity due to a fuzzy difference in the signs of normal and pathological CTG, which adds the risk of unnecessary obstetric intervention for the mother and fetus (Ayres-de-Campos D., Spong C.Y., Chandraharan E. FIGO consensus guidelines on intrapartum fetal monitoring: Cardiotocography // International Journal of Gynecology & Obstetrics. - 2015. - T. 131. - No. 1. - C. 13-24).

As well as in the similar, the disadvantages of this method include the multiplicity of procedures for isolating and classifying parameters, the need to compare the established changes in FSP with fetal movements and contractions of the uterus, as well as the impossibility of determining the type of CTG during intermittent recording of FSP associated with loss of the ultrasonic signal.

The task of the invention is to optimize the method of determining the type of CTG of the human fetus.

The technical result of the invention is to improve the accuracy of determining the type of CTG, due to the introduction of uniformity of evaluation of its relevant parameters and simplify their analysis.

The technical result of the proposed method is achieved by the fact that the method of determining the type of cardiotocogram of a human fetus includes recording a heart rhythm, isolating and analyzing significant parameters on the curve of a 30-minute recording segment.

Distinctive techniques of the proposed method lies in the fact that when registering four or more consecutive sections with a continuous increase or decrease in the range of fluctuations of the fetal heart rate (FSP) and / or registration of the prevalence of growth or decrease in PSP at 2 or more oppositely directed parts of the recording curve , establish on these sites the number of pairs of growth and the number of subsequent pairs of decline and when the number of pairs of growth is exceeded, determine the normal type of CTG.

Distinctive techniques of the proposed method also consist in the fact that when registering on a fragment of the recording curve, 2 consecutive pairs of oppositely directed sections with a more than twofold difference in the range of oscillations and a transition point between them, which coincides with the transition point between their largest sections, type CTG.

In the absence of signs characterizing the normal and pathological type of CTG, establish a doubtful type of CTG

Comparative analysis with the prototype showed that the proposed method differs from the known one by the methods listed above and, therefore, meets the patentability criterion of "novelty."

From the analysis of the patent and special literature, the authors found that the proposed method has features that distinguish it not only from the prototype, but also other technical solutions in this and related fields of medicine.

The authors of the proposed method found that based on the allocation of four or more consecutive sections with a continuous increase or decrease in the range of PSP, sequences of pairs of oppositely directed sections of the recording curve with a predominance of growth and decrease of PSPs and excess pairs of growth, repeating 2 consecutive pairs of oppositely directed sections of the curve recordings with more than twice the range of vibrations and the transition point between them, which coincides with the transition point between their largest sections, The uniformity of definition of various types of CTG is stalled.

Proposed by the authors of the proposed method, the relevant parameters will be equally perceived by different doctors, because they are identified and highlighted as consistent, clearly different from each other elements of the curve of the PSP.

Simplification of determining the type of CTG is achieved by eliminating the diversity and gradations of intermediate features (baseline, baseline variability, accelerations, decelerations), the conditions for their selection, eliminating the need to retain all the established features and multiple comparisons with standards of normal and pathological CTG.

The authors of the proposed method have established that the proposed method “works” both with an intermittent signal and in the absence of registration of contractions by means of a dynamometer, therefore, to determine the type of CTG, it is possible not to take into account the connection of changes in FSP with contractions or fetal movements when the signal is interrupted with penetration skin of the head with a spiral electrode.

In contrast to the known methods, the authors of the proposed have reduced the number of significant parameters allocated for the analysis, by establishing the connection of each of them with the type of CTG. It has been established that the normal type of CTG is characterized by a continuous increase or decrease in the range of oscillations of the PSS or “stepwise” growth of the PSP, i.e. steady increase or attenuation of oscillations or their changes in the direction of growth of PSP. And for a pathological type of CTG, there are 2 pairs of oppositely directed sections with a more than twofold difference in the range of vibrations and a transition point between them, which coincides with the transition point between their largest sections.

From the above it follows that the proposed method meets the criterion of "inventive step".

The method of determining the type of CTG of a human fetus, constituting the claimed invention, is intended for use in practical health care. The implementation of its capabilities is confirmed by the methods and means described in the application. From the above it follows that the claimed invention meets the condition of patentability "industrial applicability".

The proposed method is as follows:

On the recording curve (CC), four or more consecutive sections are determined with a continuous increase or decrease in the range of fluctuations of the fetal heart rate (FSP) and / or a sequence of pairs of oppositely directed sections of the recording curve with a predominance of growth and decrease in FSP and growth pairs exceeding and establish the normal type of CTG .

When registering on a fragment of the recording curve, 2 consecutive pairs of oppositely directed sections with a more than twofold difference in the range of oscillations and the transition point between them, which coincides with the transition point between their largest sections, establish the pathological type of CTG.

In the absence of short-term signs of normal and pathological types of CTG, a doubtful type of CTG is established.

The proposed method for determining the type of CTG is illustrated by examples of specific performance and "stretched" (for better understanding) cardio-togramgrams (Fig. 1-6), in which the positions are indicated:

1 - baseline;

2 - one-minute interval on the baseline;

3 - two pairs of oppositely directed sections on the recording curve with a more than twofold difference in the range of PSP oscillations;

4 - transition point between pairs of oppositely directed sections, which coincides with the transition point between their largest sections;

5 - variable deceleration;

6 - acceleration,

7 - four consecutive sections with a continuous decrease in the range of oscillations of the PSP;

8 - four pairs of growth of PSP;

9 - two subsequent pairs of declines;

10 - early decelerations.

Example 1

Pervibury, primipara V., 27 years old, was admitted to the maternity ward of the Irkutsk city perinatal center at 22 hours 20 minutes. Height is 178 cm. Weight is 80 kg. Body temperature is 36.8 degrees Celsius. Blood type A (II), Rh positive. Pelvis dimensions: distantia spinarum 28 cm., Distantia cristarum 32 cm., Distantia trochanterica 36 cm., Conjugata externa 19 cm., Conjugata diagonalis 13 cm. The position of the fetus is longitudinal, presented to the head, pressed to the entrance to the small pelvis. Fetal heartbeat during auscultation is clear and rhythmic, 148 beats per minute. Generic activity is regular: 3 contractions in 10 minutes, each 45 seconds.

From the anamnesis and the exchange card, it was found out that the woman has a gestation period of 39 weeks, is somatically healthy, the pregnancy was uneventful, the weight gain during the gestation period was 12 kg. In the study through the vagina at 22 hours and 30 minutes: the vagina of the fetus, the cervix - along the wire axis of the pelvis, soft, 1.5 cm long, opening the uterine throat 3 cm. The fetal bladder is intact, opened. A small amount of light green amniotic fluid has poured out. Slated to be head pressed to the entrance to the pelvis. Cape is not reachable. Diagnosis: Pregnancy 40 weeks. 1 period of labor. Amniotomy. Suspected intrauterine hypoxia.

At 22 hours 31 minutes, an external electronic monitoring of the fetal heart rate (FSP) was started. After 30 minutes of recording, the cardiotogram was evaluated.

When analyzing the recording curve of PSP at 23 hours 01 minute (Fig. 1), the following parameters were set:

- According to the method prototype: baseline 1 is determined from 22 hours 50 minutes, was 135 beats / min (normocardia); baseline variability is calculated on a one-minute interval of 2, a value of 10 beats / min is obtained; normal; There are no accelerations, no decerations. Conclusion: the normal type of cardiotogram, showing the observation of the fetus.

- By the present method: a recurring symptom of pathological CTG is established - 2 pairs of oppositely directed sections 3 on the short-circuit with more than twice the difference in the range of vibrations and the transition point between them 4, which coincides with the transition point between their largest sections. Conclusion: pathological type of CTG, emergency help is shown to the fetus.

Evaluation of the prototype method and the claimed method did not match.

Deliveries were continued conservatively.

At 24 hours 00 minutes (1 hour and 40 minutes after admission), the study was repeated through the vagina: the opening of the uterine mouth 3-4 cm, the amniotic fluid leaked light green, the head remained pressed to the entrance of the pelvis.

At 24 hours and 20 minutes (2 hours after admission) labor pain relief was initiated by epidural anesthesia.

At 24 hours 41 minutes (2 hours 21 minutes after receipt), CTG was recorded again.

When analyzing the curve of a 30-minute recording of PSP at 01.11 am (2 hours and 59 minutes after arrival), the following parameters were set (Fig. 2):

- According to the method prototype: baseline 1 is determined from 24 hours 01 minutes, was 140 beats / min (normocardia); baseline variability was calculated on a one-minute interval of 2, a value of 6 beats / min (normal) was obtained, no accelerations, repeated variable decelerations 5. Conclusion: questionable type of cardiotogram (CTG), clarification of the causes of deterioration of CTG, conservative treatment and evaluation of its effectiveness.

- By the present method: the same symptom of pathological CTG is established, as in FIG. 1 - positions 3 and 4 (Fig. 2). Conclusion: pathological type of CTG, emergency help is shown to the fetus.

Evaluation of the prototype method and the claimed method did not match.

Due to the fact that the conflict on the umbilical cord was suspected, it was decided to end the delivery by cesarean section. At 01.30 am (3 hours and 10 minutes after admission) the woman in labor was transferred to the operating room. At 01 h. 36 minutes, a female fetus was extracted 3870 g, 54 cm. With no signs of life.

Final diagnosis: Pregnancy 40 weeks. Urgent operational delivery. Intranatal fetal death. Amniotomy. Laparotomy by Pfannenstiel. Caesarean section according to Gusakov.

Conclusion: when establishing the pathological type of CTG using the proposed method, it was possible to revise obstetric tactics and provide emergency aid to the fetus 2 hours 35 minutes earlier, i.e. 40 minutes after the woman enters the perinatal center. Example 2

Repeated, repeated B, 33 years old, on July 28, at 9.20 am, she entered the antenatal department of the Irkutsk city perinatal center for preparation for childbirth and delivery during 39 weeks of pregnancy.

During the inspection and on the basis of the data of the exchange card it was established: the 4th pregnancy, the birth was coming on the 2nd; first childbirth - in 2004, a girl of 3840, without complications; subsequently there was a medical abortion and miscarriage for 16 weeks with curettage of the walls of the uterus. Weight gain during pregnancy was 10 kg; height 160 cm, weight 79 kg; blood type A (II), Rh positive. Pathological abnormalities in the size of the pelvis, the position and presentation of the fetus was not detected. The abdominal circumference is 112 cm, the height of the bottom of the uterus is 39 cm. In the period of 22 weeks after the ultrasound examination and examination by a therapist, the diagnosis is made: Urolithiasis. Chronic pyelonephritis. Chronic renal failure 0 degrees; located in the dispensary in the AIDS center. When vaginal examination established "immature" cervix.

Upon receipt, the fetal CTG was recorded, after which it was analyzed (Fig. 3) and the following parameters were set:

- According to the method - prototype: baseline 1 was 147 beats / min (normocardia); baseline variability is calculated on a one-minute interval of 2, a value of 4 beats / min (pathological) is obtained, there are no accelerations, no decelerations. Conclusion: the pathological type of cardiotogram (CTG), emergency aid to the fetus is shown.

- By the present method: a sign of normal CTG is established - four consecutive sections 6 with a continuous decrease in the range of PBS oscillations. Conclusion: normal CTG, shown to observe the fetus.

Evaluation of the prototype method and the claimed method did not match.

This type of CTG has been interpreted by the attending physician as transient (the resting phase of the fetus) and preparation for childbirth has begun with Mifepristone.

July 29, at 9 hours and 36 minutes (1 day after receipt), CTG recording was repeated (Fig. 4) and the following parameters were set:

- According to the prototype method: baseline 1 was 160 beats / min (normocardia), baseline variability was calculated on a one-minute interval 2, a value of 6 beats / min was obtained (normal), no acceleration, repeated variable deceleration 5. Conclusion: questionable type of CTG It is shown that the cause of the deterioration of CTG, conservative treatment and evaluation of its effectiveness.

- By the present method: a sign of pathological CTG is established - 2 pairs of oppositely directed sections 3 on faults with a more than twofold difference in the range of oscillations and a transition point between them 4, which coincides with the transition point between their largest sections. Conclusion: pathological type of CTG, emergency help is shown to the fetus.

Evaluation of the prototype method and the claimed method did not match.

Continued monitoring of the fetus. With the onset of labor at 12 o'clock, it was examined in the antenatal department: at the opening of 3 cm amniotomy was performed, a moderate amount of light amniotic fluid was discharged. The fetal heartbeat during auscultation was 144 beats / min, clear and rhythmic.

At 12 hours and 50 minutes on July 29, she was admitted to the delivery room, intravenous administration of the retrovir was started, and the fetal heartbeat was not recorded. At 13.25 it is examined: the general condition is satisfactory, the blood pressure is 110/70 mm Hg, the pulse is 80 beats per minute, the contractions are arrhythmic after 1-2-3 minutes for 45 seconds, the opening of the uterine mouth 6-7 cm there is no fetal bladder, amniotic fluid is light, leakage, fetal heartbeat is dull and arrhythmic 80 beats / min. In connection with the distress of the fetus, it was decided to end the delivery with a cesarean section. At 13 hours and 40 minutes, a boy was extracted 3550 g, 53 cm, without signs of life.

Final diagnosis: Pregnancy 39-40 weeks. Urgent operational delivery. Intranatal fetal death. Z21. Urolithiasis disease. Chronic pyelonephritis. Anemia 1 degree. Amniotomy. Laparotomy by Pfannenstiel. Caesarean section according to Gusakov.

Conclusion: the establishment of a pathological type of CTG according to the proposed method made it possible to change obstetric tactics 4 hours earlier and end the labor in an operational way in the interests of the fetus.

Example 3

Repeated recurrent T., entered the Irkutsk Perinatal Center at 15 hours 00 minutes, gestational age 39-40 weeks. A history of 2 births without features weighing 3000 g and 3200 g. The pregnancy was without pathology. It was observed from 13 weeks. On examination: somatically healthy, blood pressure 120/80 mm Hg, pulse 78 beats / min., Contractions regular No. 2 for 10 minutes, no external deviations of the pelvis were detected, vaginal examination cervix shortened, uterine opening pharynx 4 cm, the fetal bladder is intact, it is presented head, pressed to the entrance of the pelvis, the basin is capacious.

At 15 hours 21 minutes (21 minutes after receipt), CTG was recorded, after which it was analyzed (Fig. 5) and the following parameters were set:

- According to the prototype method: baseline 1 was 144 beats / min (normocardia), baseline variability was calculated on a one-minute interval 2, a value of 8 beats / min (normal) was received, repeated acceleration 6, repeated variable deceleration 5. Conclusion: normal type CTG, shown to monitor the fetus.

- By the present method: a sign of normal CTG is established - the predominance of growth of PSP on 6 oppositely directed sections of the recording curve. In these areas: 4 pairs of growth - 8 and two subsequent pairs

reductions - 9. The number of pairs of growth exceeds the number of pairs of decrease. Conclusion: the normal type of CTG, shown to observe the fetus.

Evaluation of the method - the prototype and the claimed method coincided.

Continued monitoring of the fetus.

At 16 o'clock amniotic fluid was poured out and at 4:30 pm she gave birth to a lively girl 3090 g, 51 cm with Apgar score of 9 and 10 points. Final diagnosis: Pregnancy 39-40 weeks. Urgent delivery.

Example 4

Repeated recurrent inhomogenous in the period of childbirth S., Entered the Irkutsk perinatal center at 6.30 am with amniotic fluid at 4.00 am with the subsequent development of labor. When viewed, and also from the exchange card installed: Height 158 cm. Weight 73.9 kg. Blood group A (II), Rh positive. 5th pregnancy, 3rd birth (the first pregnancy is ectopic, the second is frozen, the next two pregnancies in 2013 and 2015 ended in spontaneous childbirth fruits weighing 2900 g, without complications. Blood pressure 100/60 mm.rt. The weight gain for pregnancy is 7 kg. Somatically healthy. The pregnancy was uneventful. The regular contractions were 3 in 10 minutes, 45 seconds each. When examined through the vagina, the cervix is softened and shortened to 1 cm, the opening of the uterine throat is 4 cm. Amniotic fluid leaks bright. Head pressed to the entrance in the pelvis. Taz capacious.

At 6 hours and 54 minutes, CTG recording was started, after which it was analyzed (Fig. 6) and the following parameters were set:

- According to the method - prototype: baseline 1 was 125 beats / min (normocardia), baseline variability was calculated on a one-minute interval 2, a value of 4 beats / min was obtained (reduced), no acceleration, early deceleration 10. Conclusion: pathological type CTG, emergency help to the fetus is shown.

- By the present method: signs of pathological and normal types of CTG is not installed. Conclusion: suspicious type of CTG, determination of the cause, conservative treatment and evaluation of its effectiveness are shown.

Evaluation of the prototype method and the claimed method did not match.

The mother was turned on its side, but after that it was not possible to check the change in the heart rate. At 8 hours and 25 minutes (1 hour and 55 minutes after admission), the birth was resolved by a live, full-term boy weighing 2,740 g, 49 cm long, with Apgar score of 9 and 10 points.

Final diagnosis: Pregnancy 38 weeks. Urgent delivery. Premature rupture of membranes.

Under the conditions of the Irkutsk city perinatal center, 40 birth histories were analyzed using a simple random selection method. Of these, 25 stories are childbirth without asphyxia with Apgar scores at the 1st and 5th minutes of 7-10 points and 15 stories - births in critical condition, of them: intranatally dead - 5, antenatal dead - 10.

According to the prototype method, 5 resident physicians assessed CTG of fetuses with hidden (overwritten) findings of doctors who observed them during childbirth or during pregnancy.

With differences in determining the type of CTG, the majority point of view was taken; the average evaluation time was 92 ± 7 minutes.

After that, training was conducted with the same resident physicians - determination of the type of CTG using the proposed method. There were no differences in the definition of CTG type; the average evaluation time was 42 ± 5 minutes.

As a result, it was found that determining the type of CTG by the present method, compared with that of the prototype method, takes 2.3 times less time (Student's test t = 5.934, p = 0.001) and the differences in determining the type of CTG were significantly less (0 out of 40 against 9 out of 40; Fisher's exact two-sided test, p = 0.002), i.e. In both respects, differences were statistically significant.

The results of the comparison of determining the type of CTG in the prototype method and the proposed method, as well as the presence and absence of the critical state of the fetus are presented in the table below.

From the table it follows that when establishing the type of CTG in the prototype method, statistically significant differences were identified in determining the pathological and normal types of CTG. At the same time, for suspicious and pathological, as well as for normal and suspicious types of CTG, no significant differences were found, which indicates the similarity of the analyzed signs.

By the proposed method is a statistically significant difference between the pathological from the normal and suspicious types of CTG.

The sensitivity, specificity, accuracy of establishing the critical state of the fetus by the proposed method and the method of the prototype was 93%, 88%, 90% and 80%, 40%, 68%, respectively.

Thus, the proposed method makes it possible to increase the information content of determining the critical state of the fetus when compared with the method of the prototype, by increasing the sensitivity, specificity and accuracy, respectively, by 13%, 48% and 22%. This is achieved by reducing the number of analyzed parameters and the number of estimated differences, the lack of the need to group them and multiple comparisons with the parameters of the normal and pathological types.

Claims (1)

The method of determining the type of cardiotocogram (CTG) of a human fetus, including recording heart rhythm, selecting and analyzing parameters on the curve of a 30-minute recording segment, characterized in that when four or more consecutive sections are recorded with a continuous increase or decrease in the range of vibrations of the fetal heart rate ) and / or when registering the predominance of growth or decrease in PSP in 2 or more oppositely directed sections of the recording curve, the number of pairs of growth and the number of subsequent pairs decrease in these areas Nia and growth in excess of normal type steam define CTG; When registering on a fragment of the recording curve, 2 consecutive pairs of oppositely directed sections with a more than twofold difference in the range of vibrations and the transition point between them, coinciding with the transition point between their largest sections, establish the pathological type of CTG, and in the absence of signs characterizing normal and pathological type of CTG, establish a doubtful type of CTG.

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