Ultrasound doppler what. Doppler ultrasound during pregnancy: what is it? In what cases is Doppler prescribed without fail?

The use of ultrasound to monitor the progress of pregnancy has become the same usual examination, How general analysis blood or blood pressure measurement.

Almost all young mothers know the principle of operation of this research technique and completely trust it. In some cases, in addition to a regular ultrasound, the attending doctor refers the pregnant woman for an additional examination with Doppler ultrasound. What is this diagnostic used for and should I worry if there are indications for it?

Doppler ultrasound during pregnancy: what is it?

During a regular ultrasound, the doctor observes the tissues of the mother and baby, visible due to the uneven reflection of ultrasound radiation. Doppler works a little differently: when the function is turned on, an image of blood components moving through the vessels of the mother and fetus, as well as in the umbilical cord and placenta, appears on the screen.

Traditional ultrasound provides information about the location and anatomical features of organs and vessels, and Dopplerography provides information about the dynamics of blood flow in the vascular system.

Why is Doppler prescribed during pregnancy?

Many expectant mothers are sent for routine ultrasound several times, but not once for Doppler ultrasound during the entire period of pregnancy. Having received a referral for additional testing, a woman may suspect that something is wrong with her baby. Indications for Doppler ultrasound may include:

1 Cardiovascular disorders vascular system mother or fetus, which can lead to deviations in the development of the baby due to its insufficient supply of nutrients and oxygen;

2 Factors that complicate pregnancy: presence of more than one fetus, oligohydramnios, late toxicosis, general and systemic diseases of the mother, .

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3 Discrepancy between body size and fetal development parameters deadline pregnancy, which may be a consequence of hypoxia (oxygen starvation);

4 Pathological changes in the position, structure and functioning of the placenta, in which the metabolism between the organisms of the expectant mother and baby is difficult;

5 Suspicion of umbilical cord entanglement. Sometimes traditional ultrasound does not provide complete information about the position of the umbilical cord, but Doppler shows the number and location of the loops.

If a woman during pregnancy receives a referral for a Doppler ultrasound, she should not worry: in many cases, during the examination, suspicions about the presence of pathology are not confirmed.

How Doppler Ultrasound is Performed During Pregnancy

This study does not require special preparation: it is carried out as part of the usual.

The woman is in a lying position, and the doctor, after first applying a special gel, begins the examination. After analyzing the image on the monitor, he determines the position of the fetus, its activity, anatomical features, assesses the condition of the placenta and umbilical cord.

Then the Doppler function is turned on, and information about the movement of blood through the vessels is displayed on the screen.

There are two types of Dopplerography: duplex and triplex. When using the first, the sonologist examines the structure of the vessel, its patency and the speed of blood flow in it. The doctor can immediately determine the causes of blood flow disorders.

When you turn on the second type of Doppler, you can see a color dynamic image blood cells in the vascular system. This gives additional features for examination.

How often can you have an ultrasound during pregnancy?

On average, a woman visits a sonologist’s office three times during pregnancy: in the early stages to establish the fact of pregnancy, at 20-24 weeks for intermediate monitoring of the condition and development of the baby, and at 30-34 weeks to assess the readiness of the mother and baby for the upcoming birth.

If there are indications for Doppler ultrasound, it is combined with a traditional examination. Sometimes the attending physician refers for such a study more often - if it is necessary to monitor the dynamics of changes in a particular parameter.

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Practice shows that ultrasound is safe for a pregnant woman and her baby.

Over the entire period of its use, doctors have not identified a single pathology associated with the influence of this radiation. On the other hand, ultrasound beams exert pressure on tissues and cause very slight heating. The level of this influence should not go beyond the acceptable limits.

Based on the results of the Doppler ultrasound, the doctor can also adjust the tactics of labor management.

Dopplerography– a special ultrasound examination of the functioning of the blood vessels of the unborn baby. Diagnostic method is based on the so-called Doppler effect, which ultrasonic waves have - when they come into contact with moving bodies, they are reflected, thereby changing the frequency of their oscillations. As a result this effect a sensor that perceives this type of wave registers a change in frequency, which is deciphered special program and allows you to get an image in the form of a graph or picture.

What can you find out using Doppler?

Unlike traditional ultrasound examination, Doppler ultrasound can show the doctor color-coded images showing the direction of blood flow, its speed, and the areas that are blocked. During pregnancy this technique allows you to informatively and accurately study blood circulation in the placenta and the mother-fetus system as a whole. Doppler provides data that cannot be obtained with conventional ultrasound, namely:

establishes the patency and condition of the lumen of blood vessels in the baby’s umbilical cord;
fetal heart condition;
helps to find out whether the child’s blood vessels are well filled with blood;
diagnose in the first stages the development of hypoxia or insufficient functioning of the placenta, pathology of the heart, etc.

The event is especially appropriate for women with blood clotting disorders. The data obtained during the study, in combination with the results of other tests and diagnostic measures, make it possible to draw up a pregnancy management plan and a birth plan.

Types of research

Ultrasonography can be carried out in two modes. Duplex mode allows doctors to receive exact information regarding the condition of the vessel in question, its patency, and if there is a problem, data on the cause of obstruction of the vascular element.
Triplex study provides similar data, but also supplements it with a color image showing the movement of blood. This details the situation and is the most informative approach to ultrasound examination of the fetal vascular system.

How is Doppler ultrasound performed?

The procedure is no different from a regular ultrasound and in most cases even the same devices are used. The need to go for an appointment for a Doppler study not to your usual ultrasound room, but to some other clinic may be due to the fact that the machine in your hospital is not so modern and does not have additional function, allowing Doppler sonography. No special preparation is required; filling the stomach and bladder does not affect the results.

Once in the office, you will not need to perform any new actions. It will be enough to lie down on the couch, bare your tummy and relax. The doctor will apply a special gel to the skin and simply move the roller.

The procedure does not cause any discomfort or discomfort, the vaginal sensor is not used in the process. The specialist will first perform a routine ultrasound, during which he will be able to evaluate general state uterus and baby, and then determine the location of the vessel that he wants to examine in more detail. At this stage, the Doppler function is turned on, and a picture showing the blood flow appears on the screen. The entire study, especially if there are no problems, takes very little time - about a third of an hour. During the procedure, the arteries of the uterus and umbilical cord, the middle cerebral artery of the fetus and its developing aorta are usually examined.

Indications for use

Visualization of blood flow is possible from the 6th week of fetal development, but it will be most informative at a later date. Typically, Doppler ultrasound is performed at the following times:

The first time you are sent for research is around the 20th week (during the 6th month). Conducted for search purposes possible problems for their timely elimination, this activity is especially necessary for patients who have increased risk development of gestosis, intrauterine growth retardation and fetal hypoxia;
the next study can be scheduled in the 8th month of pregnancy, and at this stage it is necessary for overall assessment the condition of the child and planning the upcoming birth.

If the doctor suspects any deviations from the norm, then additional research may be prescribed. Indications for unscheduled Doppler ultrasound are:

high blood pressure;
smoking;
kidney problems;
Rhesus conflict (in mother negative Rh factor, and the baby’s is positive);
the presence of pathologies in previous pregnancies;
discrepancy between the term and the current size of the fetus;
suspicion of developmental abnormalities;
when it is discovered that the baby’s heart rate is outside the norm;
unsatisfactory test results;
complex chronic diseases mothers (for example, diabetes);
with premature contractions.

How often can I do it?

Doppler examination is a mandatory measure during pregnancy, so every expectant mother undergoes the examination at least twice as planned. Considering the safety of the event, if indicated, it is carried out as many times as necessary to control the baby’s condition, and only a doctor can determine this number. Of course, you shouldn’t visit an ultrasound unless necessary.

Is the study safe for the baby?

Every mother is concerned about the health of her unborn child, and it is understandable why questions arise regarding the safety of studies conducted during pregnancy. We can confidently say that Dopplerography is absolutely safe method. It is highly informative and can be used even at the earliest stages, and therefore it is indispensable in the system prenatal diagnosis. If it so happens that hypoxia was detected during the study, then timely treatment will help avoid a worse outcome, and sometimes only with the help of Doppler can the entanglement of the umbilical cord be examined. From this point of view, the diagnostic method is not only not harmful, but even very useful for the unborn child.

Interpretation of Doppler study

Only a doctor can decipher the results of Doppler ultrasound, since he has sufficient knowledge and experience for this. You should not try to determine the situation on your own based on the results of the study, since most likely it will simply be pointless. The expectant mother, of course, can familiarize herself with the data regarding the norm of indicators for different dates, but it is better to consult your doctor for a clear explanation. For informational purposes only, we suggest considering some Doppler ultrasound indicators and their values (data are given in the table).

During ultrasound examination with Doppler ( doppler ultrasound) uses reflected sound waves to assess blood flow through blood vessels. This helps assess blood flow through the main arteries and veins of the arms, legs, and neck. The test may show obstruction of blood flow if there are narrowings in the arteries in the neck, which can cause a stroke. Blood clots in the veins of the legs can also be diagnosed, which can break off and impair blood flow in the lungs.

can be used to determine fetal blood flow during pregnancy in order to check the health of the baby. doppler ultrasound During The sensor is located on the skin above the blood vessel. The sensor sends and receives sound waves, which are amplified by a microphone. Sound waves are reflected from solid objects, including blood cells . The movement of these cells causes a change in the reflected sound signal (Doppler effect). In the absence of blood flow, there is no change in the transmitted signal. Information about the reflection of sound waves is processed by a computer and we can see graphic image

movement of blood in blood vessels. These images can be saved for future evaluation and review. ultrasound examinations with Doppler (doppler ultrasound):

"Portable" or continuous Doppler study ( doppler ultrasound). This test uses a change in the transmission of sound waves to provide information about blood flow through a blood vessel. The doctor listens to the sounds produced by the transducer to evaluate blood flow through the area that may be blocked or narrowed. This type of ultrasound can be performed at the bedside on a portable machine to quickly assess the extent of blood vessel damage or disease.
Dual Doppler ultrasound. This study uses standard methods Ultrasound to obtain images of the blood vessel and surrounding organs. In addition, the computer converts sounds into Doppler ultrasound, which gives an idea of the speed and nature of blood flow.
Color Dopplerography. A standard ultrasound image appears in color and blood vessels are visible in the image. The computer reproduces Doppler sounds and colors, superimposing them on top of each other, this makes it possible to estimate the speed of blood flow through the vessel.
Ultrasound included – new technology Ultrasound, which is 5 times more sensitive to detecting blood flow than color Doppler. This test can provide some images that cannot be obtained with other Doppler studies. Usually this study used to assess blood flow in dense organs.

Blood flow in individual vessels is usually assessed using color Doppler or dual Doppler. With the combined use of these methods, you can get much more more information than when using them separately.

What can be detected using Doppler ultrasound?

blood clots or vessels with blocked blood flow in various parts body, especially in the neck, arm or leg. Blocked or narrowed neck arteries can cause dizziness, blurred vision, paralysis, weakness, sensory disturbances, and other signs of a stroke. Blood clots in the deep veins of the legs can cause pain, swelling of the leg, and increase the risk of pulmonary embolism.
it is possible to assess pain in the leg, whether it is caused by intermittent claudication, which is associated, in turn, with atherosclerosis of the lower extremities.
evaluates blood flow after a stroke or other condition that may have caused blood flow problems. Blood flow can be assessed using a method such as transcranial Doppler ultrasound.
The presence of varicose veins is assessed.
anatomy of the structure of venous vessels, which may be necessary to assess the conditions for tissue transplantation on a vascular pedicle, if bypass surgery is necessary.
- blood flow in the transplanted kidney or liver is assessed
-assessment of blood flow after surgery on a blood vessel
- assessment of the presence, quantity, location of arterial vessels. A disruption in the arterial blood supply to the brain can lead to a stroke.

The need for treatment, such as the use of laser or radiotherapy when removing abnormal veins.

monitoring the condition of the fetus: blood flow in the umbilical cord, heart and brain of the fetus. This test allows you to determine whether the fetus is receiving sufficient quantity oxygen and nutrients. Doppler ultrasound in pregnancy can be used to help decide when:
the embryo is smaller than it should be at its gestational age (delay intrauterine development).
Blood flow through the umbilical cord vessel can be assessed.
blood flow can be used to monitor embryo development.
if the mother has other problems, such as preeclampsia, sickle cell disease.
Transcranial Doppler may be used in children with sickle cell disease to assess their risk of stroke. In adults, it can be used to evaluate spasms of blood flow in the brain.

Preparing for Doppler ultrasound

You will be asked to abstain from products containing nicotine (cigarettes, chewing tobacco) for 30 minutes to 2 hours before the test. Nicotine causes blood vessels to contract and may give false results.

The examination is performed by a physician who is an expert in performing these examinations or by an ultrasound technologist under the supervision of a radiologist. The test is performed in an ultrasound room or doctor's office.

What needs to be done before Doppler ultrasound?

You should remove any jewelry that might interfere with your examination. You will need to remove clothing depending on the area being explored. You will be given a diaper or paper towel.

During the study abdominal cavity you will lie on your back.

For research chest You will lie on your back.

To examine the head and neck, you need to tilt your head to one side.

To examine an arm or leg, your head will be slightly raised and your arm or legs will be raised up. You may need to lie on your stomach.

During pregnancy, you will lie on your back or left side.

A gel will be applied to your skin to help the sound waves move more easily. The sensor will be placed in a gel on the skin. You must lie down. You may hear sounds that are caused by blood flow in the blood vessels.

The study usually takes 30-60 minutes.

This test is performed on both arms or legs. Even if the suspected blood flow problem is in only one arm or leg, both limbs should be tested to compare. The examination is carried out lying or sitting. Depending on which blood vessels are being tested, a blood pressure cuff is placed on one or both limbs so that pressure can be measured in one or more places. When examining the legs, the cuff may be wrapped first around the lower leg and then around the thigh. The test may be performed in several places on your leg. When examining the arm, the cuff is placed first on the forearm and then on the upper arm.

The test can be done both before and after exercise if you are healthy enough.

Examination of the veins of the arms and legs using Doppler ultrasound

For this test, you will be asked to lie down and breathe as usual. Any changes in blood flow that occur in response to changes in your breathing are noted.

The test may be repeated with the examiner pressing on the veins close to your skin to help locate the clot in the vein (compression test). The examiner may do this with your legs or arms in different positions to ensure that the blood supply is not compromised in those positions. The examiner may also squeeze your shoulder or forearm to make blood move through your veins faster (increased blood flow test). This helps assess blood flow to your heart.

What happens after a Doppler ultrasound?

While your legs are being examined, you may be asked to try to exhale with your nose pinched and your mouth closed (Valsalva maneuver). This test usually causes sudden changes in venous blood flow.

Examination of the neck arteries using Doppler ultrasound

You will be asked to lie down and place a pillow under your head. The test is performed on both sides of the neck and the results are then compared to a standard test to determine the extent of blockage or narrowing of the arteries.

Transcranial ultrasound

During transcranial ultrasound, the transducer is lightly pressed against the skin in the scalp.

Doppler ultrasound during pregnancy.

The sensor moves back and forth on your abdomen until the doctor finds the blood vessel that needs to be examined. Once the doctor has found the blood vessel, it may take time to study the blood flow.

How will you feel?

There is usually no discomfort associated with Doppler ultrasound. You may feel a cool sensation from the gel when it is applied to your skin if it is not warmed to body temperature first. If your blood pressure is taken during the test, the blood pressure cuff will be inflated.

Risks of Doppler Ultrasound

There are no known risks associated with the Doppler ultrasound test. This test is harmless to the fetus.

Doppler ultrasound uses reflected sound waves to record the movement of blood through blood vessels.

Normal Doppler ultrasound findings:

There is no evidence of obstruction of blood flow in the veins examined. The size and position of the veins are normal.
There is no evidence of the presence of blood clots in the veins examined.
When examined during pregnancy, there is normal blood flow, which indicates the supply of oxygen and nutrients to the fetus.

Pathology during examination:

If pathology is present, Doppler ultrasound may detect differences in blood flow between the left and right side patient's body. Where blood flow is blocked, the sound will be high-pitched and harsh.
An obstruction such as a blood clot, aneurysm, or narrowing of a blood vessel can be detected. The speed of blood flow can be reduced in comparison with standard indicators; by comparing it with the standard, the degree of blockage of blood flow can be determined.
Double Doppler may show irregularities in blood flow, indicating a blocked or narrowed blood vessel.
A color Doppler test may show a blocked, narrowed blood vessel or aneurysm.
A blood clot may be found in the veins if blood flow does not change in response to breathing or increase in response to a compression test or Valsalva maneuver. Indirect blockage of a vein by a blood clot can be detected by color Doppler or a compression test.
Abnormal veins such as varicose veins may be detected.
Blood flow through blood vessels that deliver blood and nutrients to the embryo may be increased or decreased.

Reasons for the impossibility of completing the study:

the area being studied is close to bony structures
inability to stay during the test
extreme obesity
pathology heart rate(arrhythmia) or heart disease, which can cause changes in blood flow even when there are healthy blood vessels
cold hands or feet - blood flow slows down
presence of an open wound in the area that needs to be examined

Interpretation of Doppler ultrasound results (Doppler ultrasound)

Interpretation of Doppler ultrasound results requires judgment qualified specialist. If necessary, the study can be repeated within short period time in case repeated studies are necessary.

Because Doppler ultrasound requires you to remain still for a while, some children may need to be sedated so that their movements do not affect the results.

Angiography and venography are x-ray studies that require the administration of a contrast agent. In many cases, Doppler ultrasound can be an alternative to venography or angiography, since this technique is faster, cheaper, and non-invasive. If Doppler ultrasound is inconclusive, angiography or venography may be performed. Angiography is more accurate than Doppler ultrasound and is considered the most accurate test to assess blood flow through an artery. Magnetic resonance angiography and computed tomography angiography may be done instead of conventional angiography because these tests are less invasive than conventional angiography. In some cases, a venography may be necessary if a problem in the vein is suspected.

Doppler ultrasound is used to examine many parts of the body and is also successfully used during pregnancy.

The article is for informational purposes only. For any health problems, do not self-diagnose and consult a doctor!

V.A. Shaderkina - urologist, oncologist, scientific editor

When I went for a 3D ultrasound, I also did a Doppler ultrasound of the fetus.
This service is not provided in the residential complex.

How many times should you do it?

fetal Doppler

Prenatal diagnosis is a set of studies that allows you to assess the condition of the child (fetus) before birth. Timely prenatal diagnosis makes it possible to identify initial stages disturbances in the development of pregnancy and adjust therapy accordingly.

One of the generally accepted methods of prenatal diagnosis is ultrasound Doppler study vessels of the mother-placenta-fetus system (Doppler ultrasound, Doppler sonography). This procedure is painless and harmless to both the mother and the fetus (subject to certain rules), performed separately or often simultaneously with an ultrasound. To carry it out, it is necessary to have special technical and software.

Although there is a widespread preconception about the dangers of ultrasound during pregnancy, numerous studies have shown the opposite. During pregnancy, ultrasound and Doppler measurements quickly, painlessly and, most importantly, harmlessly allow you to obtain information about the condition of the child.

Doppler is based on Doppler effect- change in the frequency of a sound wave when reflected from a moving object. In biological media, such an object is the cellular elements of the blood. This phenomenon was first discovered by Christian Doppler in 1842. And the first use of Doppler in obstetrics was made in 1977 to assess blood flow in the umbilical artery (Fitzgerald and Drumm. Non-invasive measurement of human circulation using ultrasound: a new method. BMJ, 1977). In subsequent years, the widespread use of Doppler ultrasound in clinical practice made it possible to significantly reduce the percentage of such serious complications, How severe forms gestosis, placental insufficiency, intrauterine growth retardation and fetal death fetus The incidence of complications during childbirth (distress syndrome, fetal asphyxia) has decreased.

Dopplerography allows you to determine the exact location of the vessel, the direction and speed of blood flow in different phases of the cardiac cycle and, thus, assess the state of blood flow in the mother-placenta-fetus system and identify early signs violations placental function. Since the violation placental circulation underlies almost all types obstetric pathology, timely diagnosis of the state of blood flow allows us to predict the risk of complications in each specific case. After all, obstetrics is, first of all, timely diagnosis and prevention.

The placenta is an organ that unites functional systems mother and fetus. She performs such important functions, such as providing the fetus with nutrients and oxygen and removing metabolic products and carbon dioxide. Having limited permeability to a number of substances, the placenta protects the fetus from many factors that enter the mother’s body (for example, drugs). In addition, the placenta performs secretory function, participating in the formation of a number of hormones and biologically active substances, necessary for normal development pregnancy. An important criterion for the normal functioning of the placenta is the adequate state of uteroplacental blood flow. After all, it is the uteroplacental blood flow that is the most important element, connecting the body of the mother and the fetus. The development of pregnancy depends on the state of the uteroplacental blood flow, and changes in it are initial signs possible violations.

The concept of uteroplacental blood flow includes the vessels of the uterus, placenta and intervillous spaces. Its formation begins from the moment of implantation of the embryo into the mucous membrane of the uterus (7-10 days after conception).

The blood supply to the uterus is carried out from two main arteries - the uterine and ovarian, which anastomose with each other, forming arcuate or arcuate arteries in the thickness of the uterine wall.

Picture 1.

From the arcuate arteries, about 100 in number, radial arteries depart, acquiring a spiral or tangle-like course in the lower third of the myometrium. From the spiral arteries, maternal blood enters the intervillous space. It is here that the transition of substances from the mother’s blood to the fetus’s blood and back occurs. Blood circulation in the intervillous space is maintained by the pressure difference. Through the veins of the decidua, blood returns to the mother's bloodstream.

On early stages During pregnancy, during successive waves of trophoblast invasion and placental formation, changes occur in the muscular walls of the small spiral arteries. They lose smooth muscle elements and turn into large vascular cavities. Due to this, the uteroplacental blood flow increases almost 10 times and becomes a system with low peripheral resistance. Gestational restructuring of the spiral arteries ends by the third trimester. During a complicated pregnancy, the normal stages of trophoblast invasion are disrupted, and the necessary physiological changes do not occur in the walls of arteries. A disturbance in the structure of the spiral arteries leads to an increase in peripheral resistance and impaired blood flow.

When performing Doppler measurements, a graphic image of the speed of blood flow during the cardiac cycle appears on the screen of the device in the form of a two-three-phase curve with a maximum level in systole (contraction of the heart muscle) - maximum systolic velocity or pulse component- and minimal in diastole (relaxation of the heart muscle) - end diastolic velocity. For each vessel there are characteristic typical blood flow velocity curves.

Figure 2

When assessing the state of blood flow highest value has not the absolute value of the speed of blood movement, but the relationship between the speeds of blood flow in different phases of the cardiac cycle.

In clinical practice for quantification blood flow conditions use the following main indicators (indices):

Systole-diastolic ratio (SDR) is the ratio of maximum systolic to end-diastolic blood flow velocity.
Pulsatility index (PI, PI) is the ratio of the difference between the maximum systolic and end-diastolic velocities to the average blood flow velocity.
Resistance index (RI, IR) is the ratio of the difference between the maximum systolic and end-diastolic velocity to the maximum systolic blood flow velocity. RI = (S-D)/S.

An important point when conducting a Doppler study is not only a quantitative, but also a qualitative assessment of blood flow velocity curves. In different vessels, depending on the stage of pregnancy, blood flow velocity curves are normal and at different pathological changes(gestosis, fetal hypoxia) have a characteristic image (early dicrotic notch, absence of a diastolic component, high diastolic component, reverse blood flow, etc.).

Thus, timely detection of deviations during Doppler measurements allows early diagnosis pregnancy complications associated with the launch of pathological mechanisms in the placenta. In addition to examining blood flow in the umbilical cord arteries and uterine vessels, Doppler examination includes assessment fetal blood flow- fetal aorta, cerebral, renal arteries, ductus venosus, which makes it possible to evaluate intrauterine condition child.

Important point- timeliness of Doppler measurements, since in practice very often the study of blood flow is carried out too late, when disorders are already pronounced and complications develop.

The first Doppler testing is permissible at 20 - 24 weeks of gestation. Examination at these times is most desirable in groups at risk for the development of pregnancy complications such as gestosis, intrauterine hypoxia and fetal growth retardation.

When conducting a routine ultrasound examination at 30–34 weeks, Doppler testing is an obligatory component in a comprehensive assessment of the condition of the fetus.

CIR recommends Doppler testing starting from 20 to 24 weeks of pregnancy, which allows not only to identify blood flow disorders in the mother-placenta-fetus system at an early stage, but also, if necessary, to begin timely therapy and more careful antenatal monitoring of the child’s condition until birth .