home » Diary » Decipher the results of dopplerography. Normative indicators of the systolic-diastolic ratio in the fallopian tubes

Decipher the results of dopplerography. Normative indicators of the systolic-diastolic ratio in the fallopian tubes

Doppler ultrasound during pregnancy is a modern diagnostic method using ultrasound, which allows you to objectively and fully examine the blood circulation of the fetus, placenta and uterus. According to the state of the circulatory system, it is possible to assess the condition of the fetus, the rate of its development - whether the baby suffers from a lack of oxygen, as well as possible pathological changes. Dopplerometry of the fetus is the only technique that can show the exact location of vascular pathology (in the uterus, umbilical cord or placenta).

Doctor's consultation based on the results of tests or ultrasound - 500 rubles. (at the request of the patient)


Why and when to conduct dopplerometry during pregnancy

Today, vascular disease is one of the most common problems in medical practice. Timely diagnosis makes it possible to identify such pathologies at an early stage of development, and at the same time, many factors that can cause the development of circulatory disorders.

The value of the procedure lies in its high information content, thanks to which the doctor is able to identify not only the already developed pathology, but also almost imperceptible preclinical symptoms of the disease. The procedure is prescribed after the complete formation of the placenta - not earlier than 18 weeks, more often at 32-34 weeks as a routine check.

If there is even a slight suspicion of fetal developmental disorders, Doppler ultrasound is performed at any time. Doppler is done in combination with , while the sensations for a pregnant woman, the procedure is no different from the classic ultrasound examination.

The essence of the method

This method of studying the circulatory system is based on the application of the Doppler effect.

For examination, the same ultrasound is used as with ordinary ultrasound examination. The difference lies in a special sensor based on the Doppler effect and the interpretation of the received data. In the study, ultrasonic waves are recorded that are reflected not from static tissues, but from moving objects - blood cells, as a result of which the frequency of the reflected rays varies greatly in comparison with those being studied. The device processes the received data and creates a two-dimensional color image. Thanks to this, it is possible to assess the speed and direction of blood flow, the anatomy and patency of blood vessels.

The duration of Doppler ultrasound is 20 - 40 minutes. It has no contraindications, no complications, no negative impact on the body. The study is completely painless and safe.

Indications

Gynecologists recommend undergoing a Doppler examination 1-2 times during pregnancy, along with . If there are problems, a fetal doppler should be done as soon as possible. Basically, dopplerometry is prescribed when the size of the fetus does not match the gestational age. The procedure is also carried out in the following cases:

  • complications in bearing a child;
  • fetoplacental insufficiency;
  • the mother has chronic and severe diseases (diabetes mellitus, hypertension, anemia, systemic diseases);
  • Rhesus conflict between a pregnant woman and a child;
  • multiple pregnancy;
  • non-immune dropsy of the fetus;
  • incorrect position of the fetus in the uterus;
  • premature maturation of the placenta;
  • entanglement of the child's neck with the umbilical cord, suspicion of hypoxia;
  • pronounced oligohydramnios / polyhydramnios;
  • preeclampsia (late toxicosis, accompanied by a deterioration in the functioning of the kidneys, blood vessels and brain - protein appears in the urine, pressure rises);
  • injury belly in a pregnant woman;
  • chromosomal abnormalities of the infant;
  • the fetus moves less than usual or no movement is felt at all;
  • unsatisfactory results of cardiotocography;
  • complications in carrying a previous pregnancy ( premature birth, miscarriage, etc.).

Also, a fetal ultrasound with Doppler should be done in cases where the mother is not 20 years old or she is over 35 years old.

What does fetal dopplerometry reveal?

Doppler helps to detect fetal hypoxia in a timely manner and avoid the problem even before the child is in danger, or to reduce Negative consequences to a minimum. With its help, the doctor can find out the reasons for the entanglement of the umbilical cord and see how many times and how tightly the baby's neck is wrapped around. Without this vital necessary information specialists will not be able to choose the correct tactics of childbirth, which endangers the health and life of the child.

Also with the help of Doppler you can see:

  • the state and rhythm of the fetal heart at rest and movement;
  • the condition of the heart valves of the main blood vessels, arteries and veins;
  • speed and volume of blood flow of the peripheral circulatory system;
  • blood circulation in the umbilical cord and placenta;
  • condition of the circulatory system, heart and kidneys of a pregnant woman.

The information obtained allows the doctor to evaluate:

  • patency and condition of the vascular bed, the presence of deviations that block the blood flow of the fetus;
  • saturation with blood and nutrients of all tissues of the child;
  • patency and condition of the umbilical cord, entanglement of the baby's neck;
  • efficiency of the placenta;
  • the state and work of the circulatory system of a woman during pregnancy.

Preparation and features of fetal ultrasound with Doppler

The procedure does not require any preparatory measures: neither diet nor fullness Bladder and stomach do not affect the results of the examination. The only recommendation is to take a break from eating for a couple of hours before the examination.

A pregnant woman needs to take the following with her: the direction and results of past tests and examinations (ultrasound, CTG, ECG), an exchange card for a pregnant woman. paper napkins and a disposable diaper or towel is not needed - everything is provided free of charge in our clinic.

The Doppler ultrasound technique is similar to transabdominal ultrasound. The woman lies on the couch with her back and exposes her stomach. The doctor applies a special gel to the area under study to improve the permeability of ultrasonic waves and then moves the sensor over it, simultaneously examining the data obtained on the monitor. An interpretation of the results is issued to the woman on the same day.

Doplerometry during pregnancy can be performed in several ways:

  • Doppler ultrasound is used to assess the direction, intensity, nature of blood flow in the vessels.
  • Duplex study - differs from the previous method in greater accuracy and information content. It is used to assess the blood flow of blood vessels and their anatomy.
  • Color mapping - the state of even the smallest vessels and their patency is coded by color.

Interpretation of the results of fetal dopplerometry

Assessment of the state of blood supply using Doppler is formed on the basis of the following indicators:

  • The systolic-diastolic ratio is the ratio of the maximum and minimum blood flow velocity;
  • Index resistance - the ratio of the difference between the maximum and minimum blood flow velocity to the maximum during the period of compression;
  • Pulsating index - the ratio of the difference between the maximum and minimum blood flow velocity to the average velocity for a complete heart cycle.

Fetal Doppler: weekly norm and prognosis for deviations

In order for the results to be deciphered correctly and all deviations to be identified, it is necessary to compare the data obtained with the standard values, taking into account the gestational age.

Indicators of the norm of the index of resistance of the uterine arteries

Gestational period (weeks)

The average index of IR of the uterine arteries

Possible fluctuation range

0,52

0,37 – 0,7

0,51

0,36 – 0,69

0,36 – 0,68

0,36 – 0,68

0,35 – 0,67

0,49

0,35 – 0,66

0,49

0,35 – 0,65

0,48

0,34 – 0,64

0,48

0,34 – 0,64

0,47

0,34 – 0,63

0,46

0,34 – 0,62

0,46

0,34 – 0,61

0,45

0,34 – 0,61

0,45

0,34 – 0,59

0,45

0,34 – 0,59

0,45

0,33 – 0,58

0,44

0,33 – 0,58

0,44

0,33 – 0,57

0,44

0,33 – 0,57

0,43

0,33 – 0,57

0,43

0,32 – 0,57

0,43

0,32 – 0,56

Normative indicators of the pulsation index of the uterine arteries

Gestational period (weeks)

Average PI of uterine arteries

Possible fluctuation range

1,54

1,04 – 2,03

1,47

0,98 – 1,96

1,41

0,92 – 1,9

1,35

0,86 – 1,85

0,81 – 1,79

1,25

0,76 – 1,74

0,71 – 1,69

1,16

0,67 – 1,65

1,12

0,63 – 1,61

1,08

0,59 – 1,57

1,05

0,56 – 1,54

1,02

0,53 – 1,51

0,99

0,5 – 1,48

0,97

0,48 – 1,46

0,95

0,46 – 1,44

0,94

0,44 – 1,43

0,92

0,43 – 1,42

0,92

0,42 – 1,41

0,91

0,42 – 1,4

0,91

0,42 – 1,4

0,91

0,42 – 1,4

0,92

0,42 – 1,41

Indicators of the right and left uterine artery may be different. The main thing is that both indicators do not go beyond the limits of the norm. If both indicators do not correspond to the norm, this indicates a violation of the uteroplacental circulation. If one indicator is for asymmetry of uteroplacental blood flow

It is important to note that at 18-21 weeks there may be deviations in indicators due to the incomplete adaptive physiological process of cytotrophoblast invasion. In this case, fetal Doppler should be repeated after 2-3 weeks.

Normative indicators of the systolic-diastolic ratio in the fallopian tubes

Doppler norm: umbilical arteries

Normative values ​​of the index of resistance of the umbilical arteries:

Gestational period (weeks)

The average index of IR of the umbilical arteries

Possible fluctuation range

0,74

0,63 – 0,84

0,73

0,62 – 0,83

0,72

0,61 – 0,82

0,71

0,6 – 0,82

0,59 – 0,81

0,69

0,58 – 0,8

0,68

0,58 – 0,79

0,67

0,57 – 0,79

0,66

0,56 – 0,78

0,65

0,55 – 0,78

0,64

0,54 – 0,77

0,63

0,53 – 0,76

0,62

0,52 – 0,75

0,61

0,51 – 0,74

0,49 – 0,73

0,59

0,48 – 0,72

0,58

0,46 – 0,71

0,57

0,44 – 0,7

0,56

0,43 – 0,69

0,55

0,42 – 0,68

0,54

0,41 – 0,67

0,53

0,4 – 0,66

Normative values ​​of the pulsation index of the umbilical cord arteries:

Gestational period (weeks)

Average PI of umbilical cord arteries

Possible fluctuation range

1,72

1,53 – 1,9

1,62

1,45 – 1,78

1,45

1,25 – 1,65

1,35

1,18 – 1,51

1,35

1,17 – 1,52

1,25

1,09 – 1,41

1,12

0,96 – 1,27

1,15

0,98 – 1,33

1,01

0,86 – 1,16

1,01

0,86 – 1,16

1,05

0,87 – 1,23

1,03

0,88 – 1,17

0,95

0,76 – 1,13

0,85

0,71 – 0,99

0,84

0,67 – 1,1

0,84

0,59 – 0,93

0,83

0,58 – 0,99

35 – 37

0,81

0,57 – 1,05

38 – 41

0,74

0,37 – 1,08

Obtaining zero and reverse values ​​of diastolic blood flow is considered a pathology. This indicates a critical condition of the fetus, the death of which will occur in 2-3 days. In this case, a cesarean section is immediately prescribed (if the gestational age is more than 28 weeks) to save the baby's life.

Normative values ​​of the systolic-diastolic ratio of the umbilical arteries:

Violation of blood flow in the umbilical cord entails a delay in the development of the child.

Doppler ultrasound norms: fetal middle cerebral artery

Gestational period (weeks)

Average PI in the middle cerebral artery

Possible fluctuation range

1,83

1,36 – 2,31

1,87

1,4 – 2,34

1,91

1,44 – 2,37

1,93

1,47 – 2,4

1,96

1,49 – 2,42

1,97

1,51 – 2,44

1,98

1,52 – 2,45

1,99

1,53 – 2,45

1,99

1,53 – 2,46

1,99

1,53 – 2,45

1,98

1,52 – 2,44

1,97

1,51 – 2,43

1,95

1,49 – 2,41

1,93

1,46 – 2,39

1,43 – 2,36

1,86

1,4 – 2,32

1,82

1,36 – 2,28

1,78

1,32 – 2,24

1,73

1,27 – 2,19

1,67

1,21 – 2,14

1,61

1,15 – 2,08

1,55

1,08 – 2,01

Maximum velocity in the fetal middle cerebral artery:

Gestational period (weeks)

Average

Possible fluctuation range

19,7

16,7 – 23

21,8

18,1 – 26

23,9

19,5 – 29

20,8 – 32

28,2

22,2 – 35

30,3

23,6 – 38,1

32,4

24,9 – 41,1

34,6

26,3 – 44,1

36,7

27,7 – 47,1

38,8

29 – 50,1

40,9

30,4 – 53,1

43,1

31,8 – 56,1

45,2

33,1 – 59,1

47,3

34,5 – 62,1

49,5

35,9 – 65,1

51,6

37,2 – 68,2

53,7

38,6 – 71,2

55,8

40 – 74,2

41,3 – 77,2

60,1

42,7 – 80,2

62,2

44,1 – 83,2

64,4

45,4 – 86,2

Normative values ​​of the systolic-diastolic ratio in the middle cerebral artery:

Normal fetal doppler readings: fetal aorta

Violations in the blood circulation of the fetal aorta can be detected only after 22-24 weeks of pregnancy.

Normative value of the pulsation index of the fetal aorta:

Gestational period (weeks)

Mean PI of the fetal aorta

Possible fluctuation range

1,79

1,49 – 2,16

1,79

1,49 – 2,16

1,79

1,49 – 2,17

1,49 – 2,18

1,49 – 2,19

1,81

1,49 – 2,2

1,81

1,49 – 2,21

1,82

1,5 – 2,22

1,83

1,5 – 2,24

1,82

1,51 – 2,25

1,81

1,51 – 2,26

1,81

1,52 – 2,28

1,53 – 2,29

1,53 – 2,31

1,79

1,54 – 2,32

1,79

1,55 – 2,34

1,79

1,55 – 2,35

1,92

1,56 – 2,36

1,93

1,57 – 2,38

1,94

1,57 – 2,39

1,94

1,57 – 2,4

1,95

1,58 – 2,41

Normative values ​​of the resistance index of the fetal aorta:

Normative values ​​of the systolic velocity of the fetal aorta:

Gestational period (weeks)

Average systolic rate

Possible fluctuation range

26,88

12,27 – 44,11

28,87

14,1 – 46,28

30,52

15,6 – 48,12

31,95

16,87 – 49,74

33,23

18 – 51, 2

34,39

19 – 52,55

35,47

19,92 – 53,81

36,47

20,77 – 55,01

37,42

21,55 – 56,13

38,32

22,3 – 57,22

39,17

23,02 – 58,26

40,01

23,66 – 59,27

40,8

24,3 – 60,26

41,57

24,92 – 61,21

42,32

25,52 – 62,16

43,06

26,1 – 63,08

43,79

26,67 – 64,02

44,52

27,24 – 64,93

45,24

27,8 – 65,81

45,96

28,37 – 66,72

46,7

28,95 – 67,65

47,47

29,57 – 68,62

Normative values ​​of the systolic-diastolic ratio of the fetal aorta:

Doppler norms during pregnancy: venous duct

The venous duct is not evaluated using indexes. An indicator of pathology is zero or negative blood flow values. Typically, these values ​​​​are obtained with fetal malnutrition, congenital heart disease, non-immune dropsy.

In the case when the blood circulation in the umbilical cord is in a critical state, but no deviations in the blood flow were detected in the venous duct, it is possible to extend the gestation to the optimal time for delivery.

How will the gynecologist understand if there is fetal hypoxia?

The doctor compares the normal Doppler readings with the result.

  • An increase in IR and LMS in the uterine arteries is a sign that the baby is not receiving enough oxygen. This will delay development.
  • An increase in Doppler for the umbilical artery is a sign of feto-placental insufficiency. This is a vascular pathology, so the fetus is already suffering. It is also a sign of gestosis.
  • If the indicators of IR and LMS in the umbilical cords with multiple pregnancy differ, this indicates that one of the babies is experiencing hypoxia (transfusion syndrome).
  • Exceeding LMS and IR in the aorta is a symptom of poor health of the child due to prolonged pregnancy, due to diabetes in a pregnant woman, with a conflict over the Rh factor, etc.
  • A decrease in LMS and IR with dopplerometry in the carotid and cerebral arteries is observed in an extremely difficult condition of the fetus, since in this case only the main organs that support life are supplied with blood. In such a situation, an artificial birth should be carried out immediately.

I noticed that the majority of pregnant women who came to me for dopplerometry, moreover, who paid for this service, have no idea what is hidden behind this word and whether they need this study at all.
Despite such a complicated title, I will try to tell you as simply as possible what it is, why, when and why this study is needed, whether it is necessary for all pregnant women in a row, and also how it relates to the results of this study.

The activities of obstetricians and gynecologists in the Russian Federation are regulated by the Order of the Ministry of Health of the Russian Federation dated November 1, 2012 No. N 572n "On approval of the procedure for rendering medical care by profile "(excluding the use of assisted reproductive technologies)"

So, in Appendix No. 5 of this order it is written: “Screening ultrasound of the fetus in the period of 30-34 weeks with dopplerometry, cardiotocography (hereinafter - CTG) of the fetus after 33 weeks.”

Thus, dopplerometry in the Russian Federation is a screening study (that is, it is done by all pregnant women) in the third trimester. Moreover, dopplerometry is performed for all patients hospitalized in an obstetric hospital in the 2-3 trimesters until childbirth. To what extent this is appropriate, we will try to figure it out a little later.

Placental insufficiency and the associated disturbance of blood flow in the mother-placenta-fetus system is the main cause of intrauterine growth retardation among fetuses without malformations, as well as one of the possible causes of pregnancy complications such as preeclampsia, premature birth, premature placental abruption, antenatal fetal death .

With the help of dopplerometry, it is possible to diagnose a violation of the utero-placental-fetal blood flow and assess the severity of hemodynamic disorders.

But if you ask an obstetrician-gynecologist who has sufficient experience in an obstetric hospital, does Doppler at a time “close to term” help reduce antenatal losses? He will most likely answer no.

A bit of history

Christian Andreas Doppler (1803-1853) - Austrian mathematician and physicist, professor, honorary doctor of the University of Prague, member of the Royal Scientific Society of Bohemia and the Vienna Academy of Sciences. Best known for his research in the field of acoustics and optics, he was the first to substantiate the dependence of the frequency of sound and light vibrations perceived by the observer on the speed and direction of movement of the wave source and the observer relative to each other.
The physical effect discovered by Doppler is an integral part of modern theories about the origin of the Universe (such as the theory of the Big Bang and redshift), is used in weather forecasting, in the study of the movement of stars, and underlies the functioning of radars and navigation systems. The Doppler effect has been widely used in modern medicine - it is difficult to imagine a modern ultrasound machine without the possibility of conducting studies based on the Doppler effect.
The first publication on the use of dopplerometry in obstetrics dates back to 1977, when D. FitzGerald and J. Drumm recorded blood flow velocity (BFR) curves in the umbilical artery using a continuous wave transducer. For the first time in Russia, dopplerometry was used to assess the condition of the fetus by A.N. Strizhakov and co-authors in 1985.
The first experience of using color Doppler mapping (CDM) in obstetric practice is associated with the names of D. Maulik et al. and A. Kurjak (1986).

What are we actually measuring?

The blood running through the vessels consists of many particles moving at different speeds at the moment of contraction of the heart (systole) and at the moment of its relaxation (diastole). If the ultrasonic wave emitted by the transducer is reflected from a stationary object, then its reflection returns to the transducer with the same frequency, and if the reflection comes from moving particles (blood flow in the vessels), then the frequency changes. The difference between the frequency of emitted and returning ultrasonic waves is called the Doppler shift.

The ultrasound machine is capable of registering a set of Doppler shifts and displaying them on the screen as a Doppler spectrum curve. Based on the data obtained, we can calculate the blood flow velocity in systole and diastole and, by evaluating the blood flow velocity curves (BFRs), draw conclusions about whether there are hemodynamic disturbances or not.

In order to assess hemodynamics in the mother-placenta-fetus system, blood flow velocities can be measured in the uterine arteries, umbilical arteries, fetal aorta, middle cerebral artery, as well as in the venous duct and vein of the umbilical cord.

The minimum mandatory volume of Doppler studies is the assessment of CSC in both uterine arteries and the umbilical artery. In the vast majority of cases, this is quite enough to exclude hemodynamic disturbances in the mother-placenta-fetus system.

If necessary, in cases of intrauterine fetal growth retardation, revealed violations of the CSC in the umbilical cord, the study can be supplemented by the study of blood flow in other vessels.
The assessment of blood flow in the middle cerebral artery based on the measurement of Peak Systolic Velocity is necessary mainly as a method of dynamic monitoring of the state of the fetus in hemolytic disease.

A little about the pathogenesis of placental insufficiency (without a medical education, this part is easier to skip and just watch placenta video )

Problems are laid already in the very early stages of pregnancy.
There are the following stages of violation of uteroplacental circulation: violation of endovascular migration of the trophoblast, insufficiency of invasion of the extravillous chorion, violation of the differentiation of placental villi.

  • Violation of endovascular trophoblast migration in the first trimester of pregnancy leads to a delay in the formation of uteroplacental circulation with the formation of necrotic changes in the placental bed, up to its complete delimitation, and subsequent death of the embryo.
  • Lack of invasion of the extravillous chorion leads to incomplete transformation of the spiral arteries, which is considered one of the main mechanisms for the reduction of uteroplacental circulation with the development of fetal hypotrophy. As a result, some of the spiral arteries do not transform throughout their entire length, while in the other part, transformations occur only in their decidual segments, without affecting the myometrial ones, which preserves the ability of the vessels to respond to vasoconstrictor stimuli.
  • Violations of the differentiation of placental villi are of great importance in the pathogenesis of PN. They are manifested by their slow development or uneven maturation with the presence of villi of all types in the placenta. At the same time, the processes of formation of syncytiocapillary membranes are disrupted and / or the placental barrier thickens due to the accumulation of collagen and fibroblast processes in the basal layer, against which the metabolic processes through the placental membrane become more difficult.
Violation of placental angiogenesis and the absence of the formation of a normal villous tree leads to circulatory disorders, impaired transport of oxygen and nutrients through the placenta. This causes a decrease in the rate of fetal growth up to a complete stop, and the consistent development of hypoxemia, hypoxia and asphyxia, against which irreversible changes occur in the cells of vital organs, final decompensation occurs, which can lead to fetal death.

The mechanism that provides an increase in uteroplacental blood flow is based on a decrease in preplacental resistance to blood flow. As a result of a complex process of trophoblast invasion, the sheath of the spiral arteries is completely devoid of smooth muscle elements and becomes insensitive to the action of various endogenous pressor agents.

From the foregoing, it becomes obvious that the study of CSC in the uterine arteries allows us to actually judge the state of the spiral arteries, the pathological changes of which are the main ones in the pathogenesis of placental insufficiency and preeclampsia, and the study of CSC in the umbilical arteries allows us to evaluate the peripheral vascular resistance of the fetal part of the placenta.

Classification of hemodynamic disorders
There are 3 levels of severity:
I degree
A - violation of the CSC in the uterine arteries with normal CSC in the arteries of the umbilical cord.
B - violation of the CSC in the umbilical arteries with normal CSC in the uterine arteries.
II degree - simultaneous violation of the CSC in the uterine arteries and umbilical arteries, not reaching critical changes (end diastolic blood flow is preserved).
III degree - critical violations of the CSC in the umbilical arteries (absence or reverse diastolic blood flow) with preserved or impaired uteroplacental blood flow.

When should dopplerography be done?

Dynamic Doppler studies conducted from the end of the 1st trimester of pregnancy showed that the maximum decrease in uterine artery resistance occurs by 16 weeks.
This means the completion of the morphological changes in the spiral arteries and the final formation of low-resistance blood flow in the pool of the uterine arteries.

That's why optimal time conducting dopplerometry is, according to most researchers, the time of screening ultrasound at 19-21 weeks of pregnancy.

However, in about a third of patients with a normal pregnancy, the completion of morphological changes in the spiral arteries and, accordingly, the final formation of low-resistant blood flow in the uterine arteries occurs by 25-28 weeks of pregnancy.

Many authors have repeatedly reported on the possibility of CSC normalization in the uterine arteries with an increase in the duration of pregnancy. According to a multicenter study, which involved 8 centers from Yekaterinburg, Irkutsk, Yoshkar-Ola, Krasnoyarsk (2 centers), Murmansk, Novosibirsk and Tyumen, normalization of blood flow was noted in 71.7% of cases. In 54.3% of observations, it occurred within the shortest time (up to 28 weeks), in 32.7% - in the interval of 29-33 weeks, and in 13% - after 34 weeks.

In this regard, if you have a violation of blood flow in the uterine arteries at 19-21 weeks, you do not need to be immediately scared, hospitalized and treated with something. You need to consult with an obstetrician-gynecologist, clarify if you have any disorders of the blood coagulation system, which could be affected by medication right now, and repeat Doppler in 2-3 weeks.
If the violations persist, but the severity of the violations remains the same, then it is advisable to repeat the study again after 2 weeks, but together with fetometry in order to assess the dynamics of fetal growth.

It should be emphasized that pathological CSCs are characterized by instability, and therefore, the numerical values ​​of the resistance index obtained in different days, may differ significantly from each other, remaining above the normative values. Therefore, there is no need to follow the numbers themselves and make erroneous conclusions that everything has become worse, or vice versa, things are on the mend.

Ib blood flow disturbance of the IB degree is not a more severe condition relative to the IA degree, but indicates that the increase in peripheral vascular resistance occurs not from the spiral arteries of the uterus, but from the fetal part of the placenta due to a decrease in the vascularization of the terminal villi.

However, there is a nuance here.
Conducted dynamic Doppler observations showed that at the beginning of the pathological process, the absence of the end-diastolic component of blood flow is detected only in individual cardiac cycles and has a short duration. As the pathological process progresses, these changes begin to be recorded in all cardiac cycles with a simultaneous gradual increase in the long zero area until the disappearance of the positive diastolic component of the blood flow throughout half of the cardiac cycle. Terminal changes are characterized by the appearance of reverse diastolic blood flow. As in cases of zero values, reverse diastolic blood flow is initially noted as a short episode in individual cardiac cycles, and then begins to be recorded in all cycles, occupying most of the diastolic phase.

In this regard, having discovered a violation of the CSC in the umbilical artery, corresponding to the IB degree, there is always a fear that we caught the beginning of the pathological process and, perhaps, did not find those isolated cases of the absence of the end-diastolic component, already talking about the III degree. Therefore, usually, if a degree IB blood flow disorder is detected at 19-21 weeks, dopplerometry control is recommended after 5-7 days. In dynamics, a blood flow disorder of the IB degree, diagnosed at 19-21 weeks of pregnancy, can also return to normal.

The normal umbilical cord has two arteries. Normally, the indicators of vascular resistance in both arteries of the umbilical cord are approximately the same. The reason for some differences in the indices of vascular resistance when assessing CSC in the umbilical arteries is that each of the arteries carries blood to approximately half of the placenta, one of which may have vascular disorders. In this case, the assessment of the severity is carried out on the artery in which the violations are more pronounced. An exception is cases of hypoplasia of one of the umbilical arteries, when the diameter of one artery is more than 2 times smaller than the diameter of the second. As a rule, blood flow is disturbed in the hypoplastic artery, but this is not related to the function of the placenta and, in most cases, does not lead to fetal hypoxia. In this case, the assessment is carried out as with a single umbilical artery, for an artery with a normal diameter.

When registering blood flow disorders at the end of the II and III trimester, the following obstetric tactics are proposed:
With I degree of hemodynamic disorders pregnant women are subject to dynamic observation using echography, dopplerography and cardiotocography with an interval of 5-7 days. If the indicators of cardiotocography worsen, daily dopplerometric and cardiotocographic monitoring of the fetal condition is indicated. In the absence of pathological cardiotocographic parameters, prolongation of pregnancy to full term is possible. Delivery can be carried out through the natural birth canal under cardiomonitoring control over the condition of the fetus.
With II degree of hemodynamic disorders Dopplerographic and cardiotocographic monitoring of uteroplacental and fetal-placental blood flow should be carried out at least 1 time in 2 days. In case of detection of pathological CSCs in both uterine arteries and dicrotic notch on the Dopplerogram, the issue of early delivery should be resolved in a timely manner. With the addition of cardiotocographic signs of severe fetal suffering in a period of more than 32 weeks of pregnancy, emergency delivery by surgery is necessary caesarean section. Before 32 weeks of pregnancy, the question of the method of delivery should be decided individually. With normal indicators of cardiotocography with II degree of hemodynamic disorders, delivery through the natural birth canal is possible under cardiomonitoring control over the condition of the fetus.
With III degree of hemodynamic disorders pregnant women are subject to early delivery. Prolongation of pregnancy is possible only with daily Doppler monitoring in such vessels as the venous duct and umbilical cord vein, as well as the absence of signs of progressive fetal hypoxia, according to cardiotocographic studies. Delivery after 32 weeks of pregnancy in a critical condition of the fetus must be performed by caesarean section. Until this time, the choice of method of delivery should be determined individually.

Is it necessary to carry out dopplerometry at 30-34 weeks for everyone?

According to order N 572n, yes, it is necessary, and the obstetrician-gynecologist will definitely refer you to this study.
But…
I will quote the leading specialist in the field of prenatal ultrasound diagnostics, President of the Russian Association of Ultrasound Diagnostic Physicians in Perinatology and Gynecology, Doctor of Medical Sciences, Professor Mikhail Vasilyevich Medvedev:

“Undoubtedly, Doppler is absolutely justified in cases of detection of IUGR. But is it worth it to conduct a Doppler assessment of uteroplacental-fetal blood flow in cases where no pathology was detected according to echography and ultrasound fetometry? My unequivocal answer to this question, based on more than twenty years of experience in the use of Doppler ultrasound in obstetric practice, is no. And that's why. Firstly, if the fetus survived to the third trimester of pregnancy without developing IUGR, this means that the uteroplacental-fetal blood flow was not significantly impaired and will not change. Secondly, CTG with automatic analysis in the third trimester of pregnancy is more sensitive in diagnosing fetal distress compared to dopplerometry, since intrauterine hypoxia begins to dominate by full-term pregnancy in the structure of antenatal pathology. And, finally, thirdly, the low information content of dopplerometry in the third trimester of pregnancy has been proven in several studies. According to E.V. Yudina, the diagnostic value of using dopplerometry in the third trimester of pregnancy was only 2%. So is it worth looking for a needle in a haystack?
  • Umbilical artery Doppler should be available for assessment of the fetal-placental circulation in pregnant women with suspected severe placental insufficiency
  • · Umbilical artery Doppler should not be used as a screening tool in healthy pregnancies, as it has not been shown to be of value in this group.
So,
  1. During the screening ultrasound at 30-32 weeks, a lag in fetal growth from the gestational age or other deviations from the norm was detected, which means that dynamic Doppler and CTG are definitely shown to you.
  2. When, according to the ultrasound data in the 3rd trimester, everything is within the normal range, then there is no special need for Doppler, but a dynamic CTG study is still recommended once every 2 weeks.
  3. You are so calmer, or the obstetrician-gynecologist observing you insists that there will be no harm from conducting this study.
  4. If you have risk factors such as:
· Current pregnancy: hypertension, preeclampsia, gestational diabetes
Previous pregnancy: preeclampsia, miscarriage or fetal death, placental abruption
Chronic diseases: arterial hypertension, diabetes, lupus, thrombophilia

So your obstetrician-gynecologist insists quite reasonably.

How is dopplerometry performed?

The study is carried out in the same way as ultrasound, in the same room, with the same sensor. No preparation is required on your part. On the screen you will see various obscure curves and hear even less understandable numbers that the ultrasound doctor dictates to the nurse. Do not worry, at the end of the study you will be told everything in detail about its results and will be given recommendations on what to do in the future.

The study of fetal-placental blood flow should be carried out in the position of the pregnant woman on her back, since it has been established that the position of the patient on the left side is accompanied by a decrease in the sensitivity and specificity of the Doppler study in assessing the severity of fetal-placental blood flow disorders and predicting perinatal outcomes.

If you cannot lie on your back for a long time, you feel dizzy, lack of air, in no case can you stand it, immediately tell the ultrasound specialist about this. There is nothing wrong with this, it just happens to compress the inferior vena cava by the weight of the uterus. It is enough to roll over to the left side and breathe calmly. After a couple of minutes, you will feel much better and you can continue. The entire study usually takes less than 10 minutes.

Due to the influence of high-amplitude respiratory movements and motor activity of the fetus on the blood flow in its vessels, the study can only be carried out during the period of apnea and motor rest of the fetus at a heart rate of 120 to 160 beats/min.
Active behavioral states of the fetus cause an uneven form of CSC, which prevents their adequate assessment. With an increase in the fetal heart rate, there is a decrease in the numerical values ​​of IR in the umbilical artery and, accordingly, with a decrease, the numerical values ​​of the indices increase.

Therefore, if your baby decided to warm up or practice breathing, or he was attacked by hiccups during the dopplerometry, then you will have to wait a bit.

A few words about dopplerometry during screening of the 1st trimester at 11-13 weeks.

The mechanism underlying the development of preeclampsia is the abnormal development of the placenta
The risk of developing preeclampsia in each patient can be determined based on a combination of the following factors:

  • Race, weight, high blood pressure in previous pregnancies
  • Blood pressure during this pregnancy
  • Dopplerometry (ultrasound measurement) of blood flow in the uterine arteries (vessels supplying blood to the placenta)
  • Maternal serum placental hormone measurements
Screening using this combined approach can identify 90% of patients who will go on to develop severe preeclampsia.
During the screening of the 1st trimester in our center, Doppler blood flow in the uterine arteries is performed for all pregnant women. But, as you can see, Doppler alone is not enough for the most reliable calculation of risks and additional analyzes are required.

Information sources:

Fundamentals of dopplerometry in obstetrics. 2007, M.V. Medvedev

Doppler utero-placental-fetal blood flow

INTRODUCTION

The Doppler effect is based on the change in the frequency of a sound wave depending on the speed of the observed emitter. In our case, it is a change in the frequency of the reflected ultrasonic signal from an unevenly moving medium - blood in the vessels. Changes in the frequency of the reflected signal are recorded in the form of curves of blood flow velocities (BFR).

Hemodynamic disturbances in the functional system "mother-placenta-fetus" are the leading pathogenetic mechanism of violation of the state and development of the fetus in various complications of pregnancy. At the same time, in the vast majority of observations, hemodynamic disorders are characterized by the universality and uniformity of changes, regardless of the state of the fetus and the etiopathogenetic factor.

A change in the normal parameters of CSC is a non-specific manifestation of many pathological conditions of the fetus, and in many cases preceding the appearance of clinical symptoms, it is important that this also applies to the main pathological conditions during pregnancy - FGR, fetal hypoxia, preeclampsia, etc. With a period of 18-19 to 25-26 weeks Doppler is the method of choice, because the biophysical profile of the fetus is informative from 26 weeks, and cardiotocography is not yet indicative.

The Doppler technique involves obtaining curves of blood flow velocities in the vessels of the utero-placental-fetal blood flow, calculation of vascular resistance indices (VR), and analysis of the results obtained.

INDICATIONS FOR DOPPLEROMETRY

V.V. Mitkov (1)

1. Disease of a pregnant woman:

Hypertonic disease;

kidney disease;

Collagen vascular diseases;

Rh sensitization.

2. Diseases and congenital malformations of the fetus

Mismatch between the size of the fetus and the gestational age;

Unexplained oligohydramnios;

Premature maturation of the placenta;

Non-immune dropsy;

Dissociated type of fetal development in multiple pregnancies;

Congenital heart defects;

Pathological types of cardiotocograms;

umbilical cord anomalies;

Chromosomal pathology.

3. Complicated obstetric history (FGR, gestosis, fetal distress and stillbirth in previous pregnancies).

INDICES OF VASCULAR RESISTANCE (VR)

To assess the curves of blood flow velocities (BSCs), the indices of vascular resistance are proposed:

2. Pulsation index (PI, Gosling R., 1975),

(S-D)/avg.

3. Systodiastolic ratio (LMS, Stuart B., 1980),

C - maximum systolic blood flow velocity;

D - end diastolic blood flow velocity;

avg. - average blood flow velocity (calculated automatically)

LMS and IR are essentially the same thing.

In the formula for calculating PI, the average value of the blood flow velocity is used, which makes it possible to more accurately assess the shape of the blood flow curve and quantitatively analyze the CSC at zero diastolic blood flow, when LMS and IR lose their mathematical meaning. However, given that in this case (for choosing the tactics of managing pregnancy and childbirth), it is important in itself to have a qualitative change, rather than quantitative nuances, and that most of the printed research papers on doplerometry in obstetrics were carried out with the calculation of LMS, then at the moment in practical work it is more expedient to use LMS.

A.N. Strizhakov and co-authors proposed a placental coefficient (PC), which allows to simultaneously take into account changes in both uteroplacental and fetal-placental blood flow, reveals a minimal deviation from the normative values ​​of blood circulation parameters in the “mother-placenta-fetus” functional system.

PC=1/(LMS ma + LMS up)

PC - placental coefficient;

SDO ma, SDO ap - systole-diastolic relations in the uterine artery and umbilical artery.

CLASSIFICATION OF BLOOD CIRCULATION

V.V. Mitkov (1).

1st degree:

A - violation of uteroplacental blood flow with preserved fetal-placental blood flow;

B - violation of the fetal-placental blood flow with preserved utero-placental blood flow;

Grade 2: simultaneous violation of uteroplacental and fetal-placental blood flow, not reaching critical changes (end diastolic blood flow is preserved).

Grade 3: Critical disorders of fetal-placental blood flow (lack of blood flow or reverse diastolic blood flow) with preserved or impaired uteroplacental blood flow.

During dynamic observation, there is no normalization or improvement in hemodynamic parameters with 1A, 2 and 3 degrees of impaired uteroplacental-fetal blood flow. Normalization of fetal-placental blood flow was noted only at grade 1B, usually in pregnant women with the threat of interruption.

CLASSIFICATION OF FETUS HEMODYNAMIC DISTURBANCES

A.N. Strizhakov et al. (2).

1st DEGREE - a violation of the fetal-placental blood flow, not reaching critical values ​​​​and a satisfactory state of the fetal hemodynamics (impaired blood flow only in the umbilical artery). LMS in the thoracic aorta - 5.52 ± 0.14, in the internal carotid artery - 3.50 ± 1.3. There is a compensatory decrease in the diastolic function index of both ventricles of the fetal heart in 58.3% of cases, an increase in the maximum blood flow velocity through all heart valves in 33.3%.

2 DEGREE - compensated violation of the hemodynamics of the fetus (violation of the actual hemodynamics of the fetus). Centralization of the fetal circulation. Reducing the maximum blood flow velocity through all valves of the fetal heart in 50% of cases, for the left sections - to a lesser extent. Further decrease in diastolic ventricular function (E/A). Prevalence of the right parts of the fetal heart remains. Pathological spectrum of blood flow in the aorta and / or internal carotid artery of the fetus. Aorta - a violation of blood circulation by the type of violations in the artery of the umbilical cord. In the internal carotid artery, an increase in the level of diastolic blood flow is a decrease in the resistance of the microvascular bed of the fetal cerebral hemispheres. In 100% of cases, circulatory disorders in these vessels are secondary to changes in the umbilical artery. The secondary nature of changes in the internal carotid artery to changes in the fetal aorta has not been established. The primary change in the blood circulation of the cerebral vessels is much less common (non-placental type of fetal hypoxia).

2 degree is not long, quickly passes into 3 degree.

3 DEGREE - a critical state of fetal hemodynamics.

The functional predominance of the left parts of the heart over the right ones is a deeper restructuring of intracardiac hemodynamics associated with the centralization of blood circulation. Increased fetal hypoxia - a decrease in transvalvular blood flow by 10.3% for the valves of the left sections and by 23.3% for the right ones. Functional insufficiency of the tricuspid valve in 66.7% of cases (flows of regurgitation). Aorta - decrease in diastolic blood flow to its absence (69.6%). Decreased resistance of the internal carotid artery in 57.1% of cases. The combination of simultaneous violations in the aorta and in the internal carotid artery more often than in the 2nd degree of violation (14.3% and 42.3%, respectively).

Stages of violations.

1 degree goes to the second after an average of 3 weeks; 2 to 3 in 1.3 weeks. It is possible to compensate for violations in various stages, more in the first stage, less in the second. In stage 3 - decompensation of fetal hemodynamics.

Perinatal losses: 1st degree of fetal hemodynamic disorders - 6.1% of cases, 2nd degree - 26.7%, 3rd degree - 39.3%.

Intensive care of newborns: 1st degree - 35.5%, 2nd degree - 45.5%, 3rd degree - 88.2%.

DOPPLEROMETRY OF THE UMBILICAL ARTERY

(normative indicators)

Registration of CSC in the umbilical artery after 18 weeks is possible in 100% of cases.

V.S. Demidov (3).

Up to 22 weeks, the determination of blood flow in the umbilical artery is not informative, since there is no normal diastolic component (a sign of placental insufficiency). A.N. Strizhakov recommends starting the study at 16 weeks.

PI decreases with increasing gestational age:

10-11 weeks - 1.92±0.47 (no diastolic component);

29-30 weeks - 1.15±0.21.

A.N. Strizhakov (12).

The threshold value of LMS during pregnancy 28-40 weeks is 3.0.

S. Gudmundsson (6).

In North America, it is proposed to use the numerical value of LMS - 3.0 as the upper limit of normal until late pregnancy.

Nomograms of the systole-diastolic ratio (S/D) during the second half of pregnancy.

V.V. Mitkov (1).

Normative indicators of the DM ratio for the umbilical arteries in the second half of pregnancy.

Normative parameters of PI of the umbilical cord arteries in the second half of pregnancy.

S.A. Kalashnikov (7).

Umbilical artery in the third trimester of pregnancy: the average blood flow velocity is 32-39 cm/sec; PI - 0.64-0.89.

L.V. Logvinenko (5).

The values ​​of blood flow indicators in the umbilical artery in the 3rd trimester of pregnancy:

SDO - 2.6±0.7; IR - 0.62±0.19.

DOPPLEROMETRY OF UTERINE ARTERIES

(normative indicators)

Registration of CSC in the uterine artery may present some technical difficulties when using black and white Doppler, since the uterine artery is not visualized and is determined "by touch" by the characteristic appearance of the CSC. The study time can take up to 30-60 minutes. When using an ultrasonic device with color Doppler mapping of the "Acuson" type, the examination time is reduced to 5-7 minutes.

M.V. Medvedev (9).

Registration of CSC in the uterine arteries is possible: in the left in 99% of cases; in the right - in 97%. Difficulties in determining occur in the first trimester of pregnancy. Indices of vascular resistance (VR) - averaged data of five cardiocycles. In the first trimester, high ISS, in the 2-3 trimesters of uncomplicated pregnancy - a high diastolic component (low peripheral resistance).

In the 2nd half of pregnancy, the numerical values ​​of the ASC of the uterine artery are stable, slightly decreasing towards the end of pregnancy.

SDO (average)

Medvedev M.V.

Musaev Z.M.

Sladkyavichus P.P.

Pathological SDO CSC in the third trimester of pregnancy - more than 2.4-2.6.

ASCs in different uterine arteries are significantly different in the third trimester of pregnancy with a lateral location of the placenta. ISS from the placenta is lower by 12-30%.

Pathological CSCs: decrease in the diastolic component of blood flow, dicrotic notch in the early diastole phase.

A.N. Strizhakov (8).

Systolodiastolic relations in the uterine artery in the 2nd and 3rd trimesters of uncomplicated pregnancy (M±m).

Pregnancy period, weeks

V.V. Mitkov (1).

Dicrotic recess - deeper violations. It is recorded when its peak reaches or is below the end diastolic velocity level.

Violation of blood flow more often in one artery (more than 70% of cases), i.e. Both arteries must be examined.

B.E. Rosenfeld (10)

IR average - 0.482+0.052.

After 29 weeks, the threshold value of LMS (at least on one side) is 2.4, IR is 0.583.

V.V. Mitkov (1).

Normative indices of IR of uterine arteries in the second half of pregnancy.

Normative indicators of PI of the uterine arteries in the second half of pregnancy.

L.V. Logvinenko (5).

Arcuate arteries of the uterus in the third trimester of pregnancy.

ISS: LMS - 2.5± 1.2; IR - 0.6 ± 0.3.

S.A. Kalashnikov (7).

Third trimester of pregnancy. Average speed - 60-72 cm/sec, PI - 0.41-0.65.

A.N. Strizhakov (12).

The threshold value of LMS during pregnancy 28-40 weeks is 2.4.

DOPPLEROMETRY OF FETUS VESSELS

(normative indicators)

V.V. Mitkov (1).

Possibility of registration:

16-19 weeks - in 50% of cases;

20-22 weeks - in 96%;

23 weeks - in 100%, 36-41 weeks - in 86%.

In the first half of pregnancy, the ASC does not change significantly.

The mean blood flow velocity increases from 20 cm/sec at 20 weeks to 30 cm/sec at 40 weeks.

Of practical interest in the study of CSC is after 22-24 weeks, because. early violations, as a rule, are not detected due to the large compensatory possibilities of fetal hemodynamics.

Cerebral vessels of the fetus.

The most informative study of the middle cerebral artery. The study of the vessel is possible only with the use of color Doppler mapping (CDM), which allows you to clearly visualize the vessels of the velius circle. CSC in the cerebral arteries have the form characteristic of the vascular system of medium resistance - without negative values ​​of diastolic blood flow.

With CDC registration of the middle cerebral artery in 95% of cases.

Blood flow velocity increases from an average of 6 cm/sec at 20 weeks to 25 cm/sec at 40 weeks.

ISS in the middle cerebral artery increase from 20 to 28-30 weeks, and then decrease.

L.V. Logvinenko (5).

Aorta: LMS - 6.0 ± 2.1; IR - 0.83±0.72.

Common carotid artery: LMS - 7.3±3.2; IR - 0.83 ± 0.17. Internal carotid artery: LMS - 4.3±1.5; IR - 0.77 ± 0.22.

V.S. Demidov (13).

Pathology of LMS in the internal carotid artery 7.0 or more (with a period of 34-38 weeks of pregnancy). The norm is 4.0-6.9.

A.N. Strizhakov et al. (8).

Internal carotid artery:

IR 23-25 ​​weeks - 0.94±0.01;

26-38 weeks - 0.89±0.01;

29-31 weeks - 0.85AO.01;

32-34 weeks - 0.8 ± 0.01;

35-37 weeks - 0.76 + 0.09;

38-41 weeks - 0.71±0.09.

LMS less than 2.3 - pathology.

D.N. Strizhakov et al. (eleven).

The internal carotid artery is recorded at 19-41 weeks. Before 25 weeks there is no diastolic component in most cases.

Decreased IR from 0.95±0.015 at 19-22 weeks to 0.71±0.09 at 38-41 weeks.

M.V. Medvedev (14).

The main indicators of blood flow in the fetal aorta and umbilical artery in the II trimester of uncomplicated pregnancy (M±m).

Pregnancy period, weeks

Studied indicator

Average linear

Blood flow velocity, cm/s

Umbilical arteries:

A.N. Strizhakov (8).

Indicators of resistance of the internal carotid artery of the fetus in uncomplicated pregnancy (M±m).

Pregnancy period, weeks

V.V. Mitkov (1).

Normative indicators of PI of the fetal aorta in the second half of pregnancy.

Normative indicators of PI of the fetal middle cerebral artery in the second half of pregnancy.

A.N. Strizhakov et al. (12).

Pathological ISS during full-term pregnancy: fetal aorta - 8.0 and above; internal carotid artery - 2.3 and below.

B.E. Rosenfeld (10).

ASC in the middle cerebral artery at a period of 22-41 weeks.

The SDO norm is more than 4.4, IR - 0.773.

The norm does not mean a satisfactory condition of the fetus.

DOPPLEROMETRIC CHARACTERISTICS OF THE DISTURBANCE

UTERO-PLACENTAL-FETAL BLOOD FLOW

V.V. Mitkov (1).

Currently, there are no sufficient grounds and convincing data to consider the use of Dopplerography as a screening method in obstetrics justified, however, the fact that Doppler study of uteroplacental and fetal blood flow has an important diagnostic and prognostic value in the group of pregnant women with high perinatal risk.

placental insufficiency.

Not all forms of placental insufficiency are accompanied by significant changes in uteroplacental and placental-fetal blood flow. Most of the false negative results seem to be related to this. Therefore, it is necessary to emphasize the need for a comprehensive accounting of the data of the three main complementary research methods: echography, CTG and Doppler. SZRP - a typical manifestation of placental insufficiency. The primary link in the occurrence of sdfd in the second trimester of pregnancy is a violation of the uteroplacental blood flow (in 74.2% of cases, sdfd occurs). With the involvement of two arteries - in 100% of cases. In the vast majority of these cases, early delivery is required. Occurring cases of an isolated violation of the fetal-placental blood flow in sdfd is associated for the most part with a violation of the structure of the placenta.

Reasons for false positive results:

1). The severity of FGR does not always correspond to the severity of fetal hemodynamic disorders, which is explained by the different adaptive response of the fetus to approximately the same severity of delay and duration of intrauterine suffering.

2). Some newborns are born with a minimal weight deficit, their condition does not require intensive monitoring and treatment and therefore is not taken into account during the analysis, while neonatologists make a diagnosis of malnutrition, guided by the weight-growth coefficient.

intrauterine hypoxia.

Of great practical value is the use of dopplerometry to detect chronic distress, which contributes to prenatal identification of groups of newborns that are subject to careful observation and treatment. Doppler study of fetal blood flow allows diagnosing intrauterine hypoxia somewhat earlier than cardiotocography.

Evaluation of CSC in the middle cerebral artery and fetal aorta gives better results in the diagnosis of intrauterine hypoxia than with a similar assessment of the umbilical artery.

The most convincing signs of fetal hypoxia are a decrease in heart rate variability and the appearance of prolonged deep decelerations during CTG, but this is more consistent with cases of critical blood flow in the umbilical artery and fetal aorta. Therefore, in the diagnosis of hypoxia, we preferred CTG, and dopplerometry and echography have priority in identifying a group of pregnant women at high risk for perinatal pathology (pregnant women in this group are subject to dynamic comprehensive monitoring and treatment).

Pathological CSCs in the venous duct, umbilical inferior vena cava and hepatic veins have a greater prognostic value compared to arterial vessels.

Uteroplacental hemodynamics is primarily disturbed. Changes in blood flow in the umbilical artery, fetal vessels, as a rule, are secondary (in 16%, an isolated violation of fetal-placental blood flow was observed).

In the 3rd trimester of pregnancy, with unexpressed clinical symptoms of preeclampsia, recorded pathological CSCs in the uterine artery precede a significant rapid increase in severity in a few weeks.

Dopplerometry allows predicting the occurrence of preeclampsia and placental insufficiency based on the detection of pathological CSCs in the uterine artery in the 2nd trimester of pregnancy, especially at 21-26 weeks.

There is a significant correlation between the ASC in the umbilical artery and the level of glucose in the blood plasma in pregnant women with diabetes mellitus. Dopplerometry of the umbilical artery has the highest accuracy in identifying a group of high perinatal risk in this disease than PPP, CTG, which allows you to more adequately assess the condition of the fetus and choose the optimal tactics for managing pregnancy.

Rh sensitization.

In proportion to the severity of Rh sensitization, an increase in the volumetric blood flow rate in the umbilical vein occurs, reaching maximum values ​​in critical cases requiring intrauterine blood transfusions. Volumetric blood flow in the umbilical vein increases by an average of 65%, specific blood flow by 27%. An increase in blood flow is a compensatory response to a decrease in hemoglobin in the blood of the fetus. The average blood flow velocity in the aorta, inferior vena cava, IR in the umbilical artery increases.

Multiple pregnancy.

With a difference in SDO CSC in the umbilical cord artery of twin fetuses by more than 0.8 with a sensitivity of 64%, a specificity of 100%, dissociated fetal growth can be established.

Cerebral vessels of the fetus.

Violation of blood flow is characterized by an increase in the diastolic component of the CSC. An increase in cerebral blood flow is a compensatory centralization of fetal circulation during intrauterine hypoxia, characterized by a redistribution of blood with a predominant blood supply to vital organs (cerebral hemispheres, myocardium, adrenal glands) - "brain sparing effect". The presence of the effect is characteristic of the asymmetric form of fetal growth retardation.

An increase in ISS is also a pathological sign. With an increase in SDS in the internal carotid artery above 7.0, signs of intrauterine infection were noted in 38.5% of cases. In 57.7% of cases, the neonatal period was complicated by pneumonia, and more than 35% of newborns were diagnosed with various CNS pathologies.

The most accurate results are achieved in the study of CSC in the middle cerebral artery of the fetus.

fetal aorta.

The nature of the change in CSC is similar to that in the umbilical artery, but the prognostic significance is higher. With the appearance of reverse diastolic blood flow, intrauterine death occurs after 24 hours. In the case of critical values ​​of fetal-placental blood flow, perinatal outcomes depend on the parameters of blood flow in the fetal aorta. With "zero" retrograde diastolic blood flow in the fetal aorta against the background of similar values ​​of diastolic blood flow in the umbilical artery, perinatal mortality is 2 times higher (52.6 and 25%), antenatal death of the fetus is 3 times higher (90 and 33.3%) according to compared with the group with normal and pathological CSCs in the fetal aorta, which do not reach critical values ​​against the background of "zero" and reverse diastolic blood flow in the umbilical artery.

A.N. Strizhakov (15).

Studies in the aorta of the fetus during pregnancy 32-41 weeks in pregnant women with preeclampsia of varying severity (79 people) were carried out when detecting a violation of blood flow in the umbilical artery - 38 people (48% of cases of the total number of examined). 21 people (55% of cases) with impaired blood flow in the aorta were identified, in all cases there was a pronounced fetoplacental insufficiency, clinically manifested by FGR of 2-3 degrees.

B.E. Rosenfeld (10).

Pathological ISS in the middle cerebral artery (22-41 weeks of pregnancy):

LMS - more than 4.4;

IR - more than 0.773.

Increased blood flow with a probability of 69.2% indicates the development of complications in the neonatal period.

Of particular interest is the increase in cerebral blood flow against the background of normal indicators of fetal-placental blood flow, hypoxia of extraplacental origin (decrease in hemoglobin, red blood cells, hypotension, etc.), which also leads to increased hypoxia with sdfd, complications in the early neonatal period.

Of considerable practical interest is the presence of normal parameters of cerebral circulation against the background of a pronounced decrease in placental blood flow. In these cases, a change in the pathological values ​​of cerebral blood flow to normal ones was noted. What is a sign of decompensation and may be due to heart failure and cerebral edema in the fetus.

Dynamic observation is important (great prognostic value for detecting fetal hypoxia).

B.S. Demidov (13).

According to the analysis of early neonatal pathology, the main cause of an isolated disorder in the internal carotid artery of the fetus (increased SDS over 7.0) can be:

1. Intrauterine infection - 21%.

2. Choroid plexus cysts of the lateral ventricles - 20%.

3.Ventriculomegaly - 4%.

4. No pathology on the part of the fetus in the early neonatal period - 12%.

Pathological manifestations in the early neonatal period.

1. Hyperexcitation of the central nervous system - 13%.

2. Pneumonia - 13%.

3. Insufficiency of cerebral circulation - 7.5%.

4. Tremor - 7.5%.

5. Skin-hemorrhagic syndrome - 15%.

1. Increasing DLS (peripheral resistance) is a high risk factor for complications in the neonatal period.

2. The most common cause of an increase in LMS is intrauterine infection.

3. Prolonged spasm of cerebral vessels plays an important role in reducing compensatory capabilities, which leads to disruption of adaptation processes in the early neonatal period.

B.E. Rosenfeld (10).

Mean value of uterine artery IR at 22-41 weeks of gestation.

1. Newborns born in normal condition - 0.482 ± 0.052.

2. Newborns born with initial signs of hypoxia in the early neonatal period - 0.623±0.042.

Doppler is a method of studying the intensity, speed and direction of blood flow in various organs and tissues. The method is safe for pregnant women, as it is based on the Doppler effect (measurement of sound frequency oscillations reflected from a moving object, in our case, from blood cells) and does not carry radiation (radiological) load.

The figure below shows a color image of a Doppler study, different color shown different direction blood, and the graph below shows the pulsatile nature of the blood flow in the umbilical cord.

Indications for dopplerometry during pregnancy:

1) Planned study

Every woman undergoes a Doppler study at least twice during pregnancy. In terms of terms, this corresponds to II (18-22 weeks) and III (30-34 weeks) ultrasound screenings and is carried out in the ultrasound room.

2) Emergency research

Development of preeclampsia

Suspicion of fetal chromosomal pathology and other developmental anomalies

Absence of fetal movements. In the absence of fetal movements within 12 hours, it is necessary to monitor the presence and level of blood flow in the vessels of the uterus and umbilical cord and the fetal heartbeat.

Violent incessant perturbations. Such movements may indicate fetal hypoxia, it is necessary to perform Doppler control of blood flow in the uterine and umbilical vessels, and if there is a risk of Rhesus conflict, in the middle cerebral artery.

Transferred infectious disease (ARVI, influenza, food poisoning and others). Infections can affect blood flow in the placenta, so Doppler control will help identify the problem as early as possible.

Decompensation of a chronic disease of the mother (arterial hypertension, diabetes mellitus, kidney disease). Decompensation of a chronic disease can be of varying severity, but the severity of the mother's condition is not always directly related to the severity of the fetus's condition. Therefore, Doppler control will help clarify the condition of the fetus and develop further tactics.

In these cases, an unscheduled study of blood flow in the vessels of the fetus and uterine arteries is performed. With the exclusion of a threat to the life of the baby, further monitoring will be carried out in a planned manner. If violations are detected, then the tactics may be different (we will consider this below), including dynamic observation with the measurement of certain blood flow parameters. Observation can be carried out on an outpatient basis, in a day or round-the-clock hospital.

3) Doppler monitoring in dynamics

Premature maturation of the placenta
- hemodynamic disturbances
- anomalies of the umbilical cord
- oligohydramnios or polyhydramnios
- Rhesus conflict / risk of hemolytic disease of the newborn (HDN)
- long-term preeclampsia
- non-immune dropsy of the fetus
- fetal growth retardation, asymmetry of fetal development
- uneven development of children from twins, especially monochorionic twins

Premature maturation of the placenta- the appearance in the placenta of changes that are present in the norm, but at a later date.

When conducting an ultrasound study with dopplerometry, the placental tissue is determined as denser, new vessels do not appear in it, the border between the uterine wall and the placenta becomes clearer. You can also identify areas with impaired blood flow, most likely these are areas of fatty degeneration (do not be alarmed if you meet “placental infarction” in conclusion, these are small areas in which blood flow is disturbed and a kind of scar has formed), calcium deposits.

Premature aging of the placenta was previously associated with the causes of miscarriage, hypotrophy of newborns, now the opinion is not so radical if the aging of the placenta is not accompanied by hemodynamic disorders.

Hemodynamic disorders- violations of blood flow in the mother-placenta-fetus system. Changes are caused by various reasons (infections, smoking, and many others) and have different severity; the frequency of observation of the patient and the performance of dopplerometry control depends on the totality of data.

During screening II, a Doppler study is mandatory.

With the help of dopplerometry, blood flow is measured in the arteries of the uterus (right and left uterine arteries), vessels of the umbilical cord, middle cerebral artery.

In case of violation of blood flow in the vessels of the uterus and / or umbilical cord, they speak of hemodynamic disorders (HDI):

HDN I A- violation of the blood flow of one of the uterine arteries (left or right), the blood supply and breathing of the fetus does not suffer. Most often, various infections serve as the cause here, so do not be surprised that, having identified a degree I A blood flow disorder based on the results of dopplerometry, the doctor will recommend an antibiotic or send you for an additional study for infections (chlamydia, ureaplasmosis, and so on). Observation in this case is carried out in a planned manner after the treatment.

HDN I B- violation of blood flow in both uterine arteries, the fetal-placental complex does not directly suffer, however, this condition requires immediate treatment and dynamic monitoring. As a rule, dopplerometry is performed 1 time in 3-5 days in the presence of a satisfactory test of fetal movements. If changes persist after treatment, the issue of hospitalization and delivery is resolved.

GDN II- violation of blood flow in the umbilical cord, requires treatment and dynamic monitoring in an obstetric hospital.

HDN III- a critical violation of blood flow, up to the registration of zero blood flow in the umbilical cord, requires immediate medical intervention.

With hemodynamic disturbances of II and III degrees, the prognosis may be different, according to various sources, the frequency of antenatal fetal death ranges from 14 to 47%. Therefore, these conditions require stationary monitoring and the solution of the issue of delivery at any time.

Umbilical cord anomalies- this is an incorrect anatomical structure of the umbilical cord and its vessels, as well as incorrect attachment to the placenta. The entanglement of the umbilical cord around the neck and / or trunk of the fetus, presentation (loops of the umbilical cord overlap the uterine os), the presence of 2 vessels in the umbilical cord instead of 3 or other variations in the number and development of vessels, tumors or inflammation of the umbilical cord, hypertortuosity or, conversely, insufficient tortuosity of the umbilical cord can be detected.

The decisive role in this group of pathologies is played by the presence / absence of impaired blood flow in the umbilical cord.

If anomalies in the development of the umbilical cord are found, then you will be offered an additional examination for fetal chromosomal abnormalities, as this is one of the markers of genetic diseases.

If the blood flow in the umbilical cord is normal, the baby develops according to the time, the ultrasound and CTG values ​​are normal, then the observation is carried out as planned.

In the case of presentation of the loops of the umbilical cord, the question is raised about the method of delivery. The situation may change, so it is best to do an additional Doppler ultrasound closer to the expected date of birth to clarify the location of the umbilical cord loops. In the case of complete overlap of the internal os, the issue is resolved in the direction of operative delivery by caesarean section, since there is a threat of fetal asphyxia during childbirth (complete clamping of the umbilical cord vessels and acute oxygen starvation of the fetus).

Both oligohydramnios and polyhydramnios are conditions that require dynamic monitoring and treatment. Dopplerometry is performed to exclude hemodynamic disorders. With normal indicators of blood flow, further observation is planned, if HDN is detected, tactics are developed individually.

Rhesus conflict is a condition in which the fetus is rejected by the mother's body. This occurs through the production of protective proteins (antibodies) and occurs in Rh-negative women who are pregnant with an Rh-positive fetus.

Measurement of blood flow velocity in the middle cerebral artery is an important indicator for monitoring the occurrence of fetal hypoxia. This indicator is most often measured in women at risk of Rh conflict, as it quickly reflects an objective picture of the child's condition. The higher the blood flow velocity, the more pronounced hypoxia.

In the presence of normal blood flow and the absence of antibodies in the blood, the patient is observed in a planned manner.

If antibodies are detected, then Doppler control of blood flow in the middle cerebral artery is performed more often. The frequency of the study is determined by the attending physician and depends on the antibody titer, the movement test, the dynamics of fetal growth (according to the height of the uterine fundus) and other indicators.

If an acceleration of blood flow in the middle cerebral artery has already been recorded, then observation is more often started on an outpatient basis, Doppler control of blood flow is performed at a frequency of 1 time in 1-5 days. Depending on the dynamics of the state and the cumulative picture of the results of other studies, the issue of hospitalization and delivery at any time is decided. Sometimes the immune response is so pronounced that a woman has to give birth up to 30 weeks.

Careful monitoring of Rh-negative patients and the appointment of additional studies helps to reduce the risk of hemolytic disease of the newborn (a disease associated with the massive breakdown of blood cells in the fetus / newborn).

Preeclampsia is a pathological condition in the mother's body, accompanied by edema, hypertension and excess protein in the urine. For the fetus, preeclampsia is dangerous for the development of hypoxic conditions. Therefore, women with moderate preeclampsia are subject to more frequent monitoring, blood flow is measured in the uterine and umbilical vessels. With the development of hemodynamic disorders, tactics are developed strictly individually, depending on the severity of the condition.

Non-immune fetal dropsy- this is the accumulation of excess fluid in the tissues and cavities of the fetus. The reasons are different, but the prognosis is always very serious. Doppler control is carried out on an individual basis.

Fetal growth retardation (FGR) is a lag in the size of the fetus from the gestational age (gestational age). This condition requires more frequent monitoring in order to detect the appearance of hemodynamic disorders in time.

IGR I degree - lag behind the gestational age for 2 weeks
IGR II degree - lag for 2-4 weeks
ZRP III - more than 4 weeks behind

FGR I degree, in the absence of other disorders, is observed on an outpatient basis, it is possible to prescribe treatment (if growth retardation is associated with infection or clotting disorders) with Doppler control after treatment.

IGR II and III degree require dynamic monitoring and addressing the issue of early delivery. If tactics are decided in favor of dynamic observation, then Doppler control is carried out with a frequency of approximately 1 time in 2-5 days.

Fetal growth retardation can be symmetrical or asymmetrical (for example, the head size is 2 weeks behind, and the body is 4-5 weeks behind). In this case, observation begins on an outpatient basis, an additional study is prescribed (Doppler, cardiotocography), the frequency of studies is individual. In the absence of dynamics in observation, the issue of hospitalization in the department of pathology of pregnancy is decided.

uneven development of twins- a condition when one of the fetuses lags behind in development. Normally, there is always a slight difference in weight. Dopplerometry plays a significant role here, the study is performed separately for each fetus and the numbers may vary, if both babies have blood flow indicators within the normal range, then you should not worry.

Fetofetal transfusion syndrome. Measurement of blood flow in the umbilical cord is a very important diagnostic aspect, as it directly reflects the condition of the fetus. With twins, especially if it is monochorionic monoamniotic twins (in which all nourishing and protective structures are common for two), pathological conditions such as fetofetal transfusion syndrome (uneven distribution of blood flow when one of the fetuses begins to suffer, up to zero blood flow in the umbilical cord) can be detected one of the fruits). Now in some clinics there is the possibility of treating this condition (the imposition of terminals that uncouple the blood flow of the fetus).

Doppler contraindications

There are no contraindications to dopplerometry, the method is safe and is performed as many times as required.

Dopplerometry is NOT performed in cases that are obviously subject to emergency intervention (prolapse of the umbilical cord, obvious vaginal bleeding, severe maternal condition caused by eclampsia, acute fatty liver, HELLP syndrome, trauma not associated with pregnancy, stroke, etc.). Conducting dopplerometry in these cases prolongs the examination time and worsens the life prognosis of the mother and fetus.

How is dopplerometry performed?

You come to the ultrasound room at the appointed time. Special preparation is not required, the study is carried out with a transabdominal sensor, that is, a neutral conductive gel is applied to the skin of the abdomen and the doctor drives the sensor, measuring blood flow parameters, as with conventional ultrasound. The study takes approximately 5 to 30 minutes.

With the result of dopplerometry, you go to your obstetrician-gynecologist, in the presence of certain disorders, it is advisable to get an appointment on the same day in order to start treatment (if necessary) as early as possible.

The conclusion of the Doppler study will contain a brief description: “normal”, “placental disorders with HDN IA”, “zero blood flow in the umbilical cord of the II fetus”, and so on.

Your obstetrician-gynecologist will tell you a detailed explanation and further tactics. Approximate terms and frequency of observation at different pathological conditions we discussed above, but I repeat that in each case the tactics are individual.

Never refuse the proposed control study, we cannot ask the baby about his well-being, but we have the opportunity to conduct a safe study that shows an objective picture and helps to choose the treatment, choose the observation tactics and decide on prolonging the pregnancy. Look after yourself and be healthy!

Obstetrician-gyncologist Petrova A.V.

Nine months of pregnancy is a special period in the life of every woman. Different expectant mothers have different attitudes towards their new position - someone is constantly worried that everything is correct and consistent, someone remains in their usual mode.

Someone is covered by anxieties and worries for a small life, and someone does not even notice the course of pregnancy. Many women change their habitual sleep and diet, sign up for gymnastics for pregnant women, lectures for new parents and improvement courses.

Meanwhile, another category of women is quite satisfied with going to work in the usual way and the experience of a friend who has given birth three times. The environment plays a huge influence on well-being and self-awareness in a new role.

So, having heard enough stories about the dangers of ultrasound, the expectant mother can stubbornly refuse to diagnose, fearing to harm the baby. Or quite the opposite: a woman wants to undergo an ultrasound diagnosis as soon as possible in order to determine if the child has any problems and whether treatment is required.

Ultrasound is necessary in order to look at the placement of the child in the womb and assess the course of its development. Sometimes additional ultrasound diagnostics, called dopplerometry, is needed. Let's talk about her.

What can be learned from pregnant women using dopplerometry?

Dopplerometry during pregnancy is necessary in order to study the blood flow in the vessels of a woman, determine its direction and speed in the arteries and veins, find out the width of the lumen of the vessels and determine intravascular pressure. Thanks to dopplerometry, you can also examine the condition of the baby: his heartbeat, patency and lumen of the vessels of the umbilical cord, blood supply to organs, diagnose hypoxia or entanglement with the umbilical cord.

Types of dopplerometry?

Pay attention to the nuance that dopplerometry can be two different types: duplex and triplex scanning. Duplex scanning is aimed at viewing the vessels and their patency, their anatomy, and blood flow velocity. Triplex scanning adds a color image. Triplex scanning is considered more accurate. The good news is that no special preparation is required for the procedure.

Dopplerometry norms during pregnancy by week table

Norms of the Resistance Index for the uterine artery

Norms of the Resistance Index for the umbilical artery


Is dopplerometry safe for the fetus

Dopplerometry is absolutely safe and is not capable of causing significant harm to your baby. Plus, it's completely painless. An additional argument for undergoing this procedure is that most diseases are easier to prevent than to treat later. It is very important to notice malfunctions in the functioning of blood vessels, both for future mother, and for her child, because it washes to save the life and health of both. After the procedure, it will be easier to determine the most suitable look childbirth.

How long do dopplerometry during pregnancy

Dopplerometry, as a rule, is prescribed in the last trimester of pregnancy or a little earlier, starting from the twenty-third week and right up to the thirty-fourth. However, the appointment of this type of examination is at the discretion of the doctor and can be done much earlier. In the presence of preeclampsia, high blood pressure, diabetes mellitus, preeclampsia. Kidney problems, poor heredity Doppler can be prescribed for early dates. If a woman cannot say goodbye to such bad habit Like smoking, you simply cannot do without an examination.

It is up to you to decide whether or not to undergo dopplerometry. However, please note that if you have clear indications for an additional examination, it is better not to refuse. This will help you find inner peace and prevent possible troubles related to the health of you and your baby.



Share:

Similar articles