For some women who are in an “interesting position,” the doctor may prescribe a procedure such as dopplerometry during pregnancy. But here is what it is, why is it actually needed and in what cases is it prescribed? These and some other questions arise in the head of every expectant mother. And the first thing that comes to mind is whether such a study is safe? Let's try to figure this out and much more.
General information
With the help of a conventional ultrasound, the very fact of pregnancy is determined, after which the woman will have to register in the antenatal clinic so that her position is under vigilant control. This is a mandatory procedure and is carried out several times during the whole period. Ultrasound allows you to assess what condition the fetus is in, whether there are any abnormalities.
Dopplerometry of the fetus is a type of ultrasound examination, the purpose of which is to determine the state of blood supply between the female body and the child. In another way, it is called dopplerography (Doppler ultrasound scan). This study is used not only in obstetrics, but also in gynecology.
With ultrasound diagnostics, the state of blood flow in the veins and arteries is assessed, that is, its speed, whether abnormalities, functionality are present in the placenta. The result of the study is recorded in the dopplerogram. For specialists in the field of obstetrics, it is important to determine the speed of blood flow in such vessels as:
- Uterine artery.
- Umbilical artery.
- Middle cerebral artery of the fetus.
- Aorta of the fetus.
- Veins of the umbilical cord.
Dopplerometry of the fetus allows doctors not only to calculate how fast the blood moves through the vessels of interest, but also to identify existing hemodynamic disorders. Without fail, the uterine arteries (left and right) and umbilical arteries are of most interest in the study.
This is quite enough to determine the state of the blood flow in the mother - placenta - fetus system, which, in turn, allows timely detection of any violations. As for the remaining vessels, they are examined under certain circumstances. This may be a detected pathology in relation to the uterine arteries and umbilical cord vessels.
The essence of the technique
In 1842, the Austrian mathematician Christian Doppler discovered an effect that in our time allows us to determine the speed of blood flow in the circulatory system of the human body. It is on it that the principle of the operation of Doppler ultrasound during pregnancy is based.
The movement of blood through the vessels is due to the work of the heart. Moreover, in the phase of contraction of the heart muscle (systole), it moves at the same speed, while in the relaxation phase (diastole) it is different.
This can only be detected with the help of a special device called the Doppler. An ultrasonic wave emits from the sensor, which has the ability to bounce off objects. If it is stationary, then the wave returns, while maintaining the frequency. However, if the object moves, then the frequency no longer remains constant, but changes. In this case, a difference is formed between the outgoing and incoming signal. Therefore, this technique is relevant for determining blood flow velocity.
Varieties of Doppler ultrasound during pregnancy
Currently, two main methods are used:
- Duplex scanning.
- Triplex scanning.
With duplex scanning, the strength of blood flow is checked, the state of the vessels and their patency are taken into account.
Triplex scanning (or, in other words , color Doppler mapping-CDC) is almost the same, since the goals are the same. The only difference is that with this method a color image is formed. That is, a different speed of blood flow is indicated by its shade. Thanks to this, the CDC is a more visual way in which reliable information about blood flow in the main vessels of the female body and fetus can be obtained.
Dopplerometry in obstetrics
One can hardly argue with the fact that at present, mankind has reached certain heights in relation to various fields of activity. And medicine is no exception. Diagnostic equipment is constantly being improved. Take, for example, x-rays - modern devices are characterized by much less harmful radiation. Ultrasound machines have the same indicators.
For many of us, it’s important to know how healthy they are. This is especially true for pregnant women, because under the heart they carry a new life! Fearing that the study may harm the child, some mothers abandon him. But with this act they expose their baby to no less risk. Is such a decision justified regarding dopplerometry during pregnancy?
There is no consensus on this matter, although most experts in the field of obstetrics and gynecology still recommend not to refuse such a study. In their opinion, it is completely safe for both the mother and the fetus. The harm from ultrasonic waves is doubtful even after the second trimester.
In any case, judging by the safety of dopplerometry, this study can pose the same threat as any other ultrasound procedure.
Dates
How long do dopplerometry do during pregnancy? A simple ultrasound, which is a mandatory procedure, is performed as planned or according to medical indications. Dopplerometry is prescribed when it is really needed. As a rule, this is the period from the 21st to the 22nd week. During this procedure, the following is performed:
- The blood flow of the mother - placenta - fetus system is evaluated.
- The position of the fetus in the uterine cavity is determined.
- The risk and degree of entanglement of the umbilical cord is revealed.
- The condition of the heart and the main vessels of the fetus is assessed.
It is at this stage of pregnancy that reliable results are obtained, since signs of palpitations and blood supply can be detected only at this time. Nevertheless, ultrasound can be performed at a later date of bearing a child: from the 30th to the 34th week. Often, dopplerometry of the placenta for the period of the third trimester is combined with the usual ultrasound procedure.
Medical indications
The need for Dopplerometry is determined only by the obstetrician-gynecologist who leads the pregnancy. The planned dates for this procedure are given above, but there are special medical indications in connection with which an additional study is prescribed. These may include:
- Bad habits of the mother like alcohol and drug addiction, smoking.
- Diseases of the female body in chronic form.
- The presence of gestosis.
- Autoimmune diseases.
- Multiplicity or large size of the child.
- Long gestation period.
- The threat of placental abruption.
But in addition to this, Dopplerometry is also indicated for Rh-conflict pregnancy. It is carried out once again, if in the course of a previous study any pathology such as fetal development retardation syndrome, multiple, water shortage, etc.
Features of preparation for the procedure
Most pregnant women experience anxiety on the eve of Dopplerometry. Only this should be avoided, since any similar conditions of the mother in a certain way affect the development of the child. Therefore, the first thing you need to calm down and pull yourself together - as already noted above, USDG poses no threat to the baby or mother. In addition, the examination is painless, without discomfort.
Is Doppler measurement done during pregnancy by compulsory medical insurance? It is included in the list of mandatory procedures for pregnancy management approved by the Ministry of Health of the Russian Federation. Consequently, such a service will be provided free of charge in state clinics. As for private, it is necessary to clarify whether it works in the compulsory medical insurance system and whether a specific examination is carried out there. In this case, dopplerometry will be done for free. The procedure itself can proceed as follows:
- In state medical institutions. You will need a sheet or a towel to cover the couch. In the pharmacy you can buy disposable diapers, sometimes they are much more convenient to use than a towel. You also need to take care of paper towels, which will be needed to remove the remnants of the gel.
- Research can be done in any private clinic, where such disposable sets, including wipes, are issued free of charge, since all this is included in the final cost of the procedure itself.
It is not necessary to adhere to any strict diet. On the eve of the procedure, it is better to refrain from excessive consumption of vegetables and fruits. Gas formation may increase due to coarse fiber, which will significantly complicate the diagnosis. A heavy meal and a plentiful drink will lead to the fact that the doctor can not see anything.
About the procedure
Dopplerometry is performed in an ultrasound room, and its duration depends on a number of factors. For experienced professionals, this takes from 20 to 30 minutes. At the same time, if any pathology is detected, the duration can be increased for obvious reasons.
How is dopplerometry performed during pregnancy? A woman is laid on a couch on her back. But sometimes the doctor will ask the woman to turn on her left side, which will be needed mainly when the expectant mother is in the III trimester. In this case, the pressure of the enlarged uterus on the inferior vena cava decreases markedly.
An ultrasound doctor applies a special hypoallergenic and safe gel to the stomach. Such products undergo multi-stage testing before use, and only then are they approved for use in relation to pregnant women. The gel lacks color and odor, and in its consistency it resembles a thick glue. After that, the doctor picks up a sensor that touches the surface of the skin of the abdomen. An image appears on the screen at this time.
The study allows us to assess the condition of the three main blood flow systems, on the basis of which the results of Dopplerometry are displayed:
- fetal PC;
- uteroplacental MIC;
- fetal placental PPK.
In the study of BMD, the probability of placental insufficiency is determined, while PPK allows you to identify the severity of this pathology (if any). On a PC, you can judge the condition of the child.
Result Characteristics
According to the results of the study, one can judge the speed of blood flow in the body of the expectant mother. For this, the indices of vascular resistance (ASC) are determined:
- Resistance Index (RI or IR).
- Ripple index (PI or PI).
- Systolic-diastolic ratio (SDO).
RI should be understood as the ratio of the difference between the maximum and minimum blood flow velocities to the maximum value of the velocity in the compression phase. Its formula: IR = (SD) / C, where C is the maximum blood flow velocity in the systole phase, and D is the same, only in the diastole phase. The calculation is carried out over several cardiac cycles, and then the average value is determined.
PI is a slightly different attitude: the same speeds, only to the average blood flow velocity. Here the formula is slightly different: PI = (SD) / M, where M is the average rate of blood flow.
As for DLS, this abbreviation for dopplerometry during pregnancy conceals the ratio of the maximum speed in the systole phase to the minimum in the diastole period. Here the formula is simpler: SDO = SD.
Impaired blood flow
Dopplerometry allows you to diagnose any pathology of fetal development, even in early pregnancy. At the same time, doctors divide them into several degrees, depending on the severity of the manifestation:
- IA or IB.
- II degree.
- III degree.
Violations of the IPC belong to class IA. Serious disturbances in the blood circulation of the child do not occur, as well as signs of intrauterine growth retardation or fetal development.
Changes in the BCP are already in class IB. What is characteristic, the picture here is the opposite of what is presented above. In other words, there are no pathologies regarding IPC, and the violations concern only the message of the blood vessels of the fetus and mother. Just in this case, there may be signs of intrauterine growth retardation and development of the child.
If during the decoding of Dopplerometry during pregnancy a second degree of pathology is found, then this indicates the presence of a variety of disorders that affect almost the entire circulatory system of the female body and fetus. Changes occur not only in the IPC, but also in the PPC. Although this situation is more serious, there is still no threat to the life of the child.
The third degree of impaired blood flow indicates a strong impairment of blood flow in the child. As a result, the intake of necessary trace elements is significantly reduced, if no measures are taken, this leads to the death of the fetus. Therefore, with this diagnosis, emergency medical care is needed.
Regardless of the degree of pathological changes in blood flow, a necessary and special course of treatment is prescribed to a pregnant woman. In addition, you will need to undergo Dopplerometry again to observe the course of changes in dynamics.
Norm indicators
The blood flow rate is directly dependent on the gestational age of the child. Therefore, it is important to correctly determine the actual pregnancy, otherwise the reliability of the results of the study is called into question. In connection with this interpretation of the results, only a doctor should be engaged and no one else. However, only a specialist should also be engaged in determining the actual gestational age. In the article, you can find a table that reflects the indicators of the norm of Dopplerometry during pregnancy by week.
If the results of the studies do not show deviations from the norm, then the child’s development proceeds without complications, all the necessary nutrients are delivered to him in an uninterrupted mode. However, sometimes there may be slight deviations during Doppler measurements. This should not be scared, because all this is easily adjusted if necessary.
In conclusion
From all this, the only true conclusion can be drawn: Dopplerometry is a fairly reliable and informative diagnosis, which allows timely detection of pathological changes in the circulatory system of the female body and fetus. This allows you to make a forecast of the further course of pregnancy and assess the severity of the pathology. Depending on this, move on to the necessary measures.
During dopplerometry during pregnancy, it is also possible to detect hypofunction of the corpus luteum and identify other pathological changes that pose a direct threat to the mother and child. For this reason, do not ignore all the recommendations of the doctor who leads the pregnancy. Only in this way can many consequences be avoided, and a healthy and full-fledged baby will be born to the joy of parents!