Doppler ultrasound in pregnancy and the rate of decryption
A method such as ultrasound during pregnancy Doppler for many years, used for pregnant women. It allows not only to investigate the bodies, thereby revealing the existing disease, but also carefully to examine the blood flow in the umbilical cord, uterus, and blood vessels of the fetus, as it has a direct impact on the life and development of the baby.
What is a Doppler?
Thanks to the performed ultrasound diagnosis a woman can get confirmation about her pregnancy, and sometimes for the first time to learn about it. Moreover, this procedure can be done not only in early pregnancy, but also during its course. It was the Doppler ultrasound in pregnancy will enable professionals in a timely manner to determine the condition of the baby inside the womb amniotic fluid the placenta, and even reveal some pathology that can interfere with normal labor activity.
If the pregnancy is normal, in the middle of the second trimester, a woman is referred for a Doppler ultrasound, which is performed with the aim to evaluate the arterial and venous blood flow in the system mother-placenta-fetus and all of its features.
Before you understand how is the Doppler, you must know that the purpose of this procedure was to examine the state:
- uterine arteries;
- middle cerebral artery of the baby;
- the arteries of the umbilical cord;
- the aorta of the fetus.
Often women who saw the direction, wondering — what is the Doppler for pregnant women, as this name is a little different. This is actually the same, but the Doppler in pregnancy so named because of the LDF, which is a result of the study.
Doppler is of two types:
The first option is more simple and only shows the blood velocity superimposed on the two-dimensional image.
Triplex allows you to see the direction of the blood, thus it provides more accurate data for analyzing. Mothers are not always clear on how to carry out manipulations with the Doppler during pregnancy and what it is, since watching on the monitor erroneously think that different colors indicate different components in the blood, but actually is the blood going to the sensor one color, and from it another.
How is the study
All dopplerograms built on the basis of the analysis of the difference in the frequencies sent by the probing and reflected signals from the investigated moving objects. More specifically, here we are talking about the formed elements of the blood, i.e. erythrocytes, are environment guide.
Through the Doppler in obstetrics, specialist registers the ultrasound signal, wherein analyzing the frequency and spectral characteristics of the signal, and then investigate the difference of the near-wall and Central flows. Experienced doctor easy to notice the presence of ultrasound signs of any abnormalities in the so-called “sound” signal.
A Doppler ultrasound of the fetus based on the Doppler effect, which is a special sound wave is ultrasonic. After the sound is reflected from the object is displayed on the screen image in the form of a graph and gray-white.
Doppler is performed in several modes, namely:
- Spectral or continuous.
- Pulse wave, that is, the signal in this case is sent with a periodicity of: once it’ll be sent next.
- Color Doppler mapping, which is performed with anatomical M-mode. Moreover, the color image displayed with different colors in different parts of the vessels. After that the data are superimposed on the two-dimensional image, similar to the results of ultrasound during pregnancy.
Violations of the utero-placental circulation
- I degree. Its development occurs in two cases:
- IA – utero-placental blood flow is disturbed, in the umbilical artery is maintained;
- IB – violation of placental blood flow in intact uterine-placental.
- II. Dysfunction of blood flow in uterine arteries, and in vessels of the umbilical cord, but CBC is normal.
- Grade III (zero blood flow). The critical values of placental blood flow and the arteries of the uterus it can be normal.
In the first case, treated on an outpatient basis, then it is necessary to carry out ultrasound Doppler to compare the result for weeks. Treatment with medications is not always effective, but it is useful often to walk in the fresh air, move more and eat right.
If the violation is a second or third degree, in need of constant surveillance, which is done in stationary conditions. Especially dangerous is the third degree, as there are risks of placental abruption, death of the baby and premature birth is very high. In violation of blood flow II degree of Supervisory Doppler daily or every other day. In the period after 32 weeks additionally appointed to CTG (cardiotocography – assessment of the fetal cardiac activity) daily.
When serious violations of third degree begin to approach the critical value, there is a direct threat of life and in this case, it is often prescribed to premature delivery.
Doppler in obstetrics is appointed for a specific term at 18 – 21 weeks because that is when a specialist is necessary to determine:
- uterine-placental-fruit bloodstream – igpc (this is uterine artery Doppler);
- anomalies in the umbilical cord;
- the possible presence of entanglement of umbilical cord, and received as a result of hypoxia;
- polyhydramnios and oligohydramnios;
- the position of the fetus;
- malformation of the brain or heart of a child;
- the condition of a heart of a baby;
- pathology of the placenta;
- main artery in a child;
- the size of the fetus in case of doubt during obstetric examination.
If normal repeat examination is performed at the period of 32 to 34 weeks (along with the third ultrasound screening). In the case of abnormal Doppler is often. The frequency of study will depend on the degree of impaired blood flow.
For each expectant mother needs to know that ultrasound with Doppler ultrasound do not differ in safety, comfort and no subsequent negative consequences. This method is most effective for a General examination of the patient.
Preparation for the procedure
In order to make the results of Doppler imaging was accurate, the expectant mother need not to worry about how to make a Doppler in pregnancy, it does not require special training. The whole procedure is performed only in the supine position on the back or side, the skin should be smeared with a special gel, which allows to improve the contacting of the sensor with the skin and facilitate its sliding. The whole procedure lasts about half an hour to fill your bladder before the manipulation should not be.
An interesting fact is that in the case of pregnant use tobacco products the result will be distorted. That is why a few hours before the scheduled procedure, she shouldn’t be Smoking.
There are two types of diagnostic ultrasound in pregnancy:
- it can be carried out normally;
- be accompanied by the mapping using color, that is, any direction of blood flow is shown by color.
Of course, the second option is more reliable as to detect the presence of pathologies in this case much easier.
For holding the Doppler in obstetrics, in most cases there are no special indications and it is performed as planned in the period of 18 – 21 and 32 – 34 weeks. But sometimes there are situations when mother and baby in danger, then she is in for another term. Examples of such conditions are:
- harmful habits of the mother;
- many — or oligohydramnios;
- severe chronic disease;
- autoimmune rejection;
- large fetus or multiple children;
- previous pathology or miscarriage;
- the transition for the appointed time of the birth;
- the placenta must have detached;
- conflict RH factors;
- changes in CTG;
- rare or very active fetal movements;
- the threat of termination of pregnancy;
- various injuries that were obtained during pregnancy.
When you need to do a uterine artery Doppler, ultrasound doctor determines the blood flow parameters in both of them, as such a dangerous pathology in pregnancy as preeclampsia leads to violations of blood flow in one artery or in both at once. Of course, the second option is more dangerous, as there is a violation of the utero-placental circulation.
The results of the study
Doppler explores the blood flow in certain systems of vessels, namely:
- PC — fetal system. This study evaluates the overall condition of the fetus.
- PPK — fetal-placental. Helps to track the severity of placental insufficiency, and to determine quantitative and qualitative features necessary to provide the baby with nutrients and oxygen.
- IPC — uterine-placental system, which provides blood flow of the venous duct of the uterus. This analysis helps to study the quality of the blood supply of the placenta, although held as a Doppler ultrasound of the vessels of the uterus.
By itself, the fetal aortic blood flow represents the supply of blood, and with the average parent artery and the internal carotid, thanks to the ongoing Doppler and its decoding, the specialist can see the whole picture.
When there is an explanation indicators LDF, the technician can adequately assess the velocity of blood flow, which can be both maximum and minimum. The first variant occurs at the time of compression of the blood vessels, and the second at the stage of relaxation. Once the data is Doppler ultrasound during pregnancy conducted, experts count the ISS, that is, the indexes of vascular resistance:
- RI is the resistance index, which represents the ratio of the difference of the speeds to the maximum;
- PI is the index of pulsation of the relationship of the difference to average speed.
- DLS is systolicdiastolic the ratio of the maximum speed during compression (systole) and lowest during relaxation (diastole).
In order to identify a pathology, these data should be compared to standards specified in a special table, which vary depending on the term. It is especially important to check IR in the umbilical artery, as this may indicate early signs of disease. When the value of the LMS in the umbilical artery is more or less the norm, experts prescribe drug treatment in stationary conditions.
There will be held a transcript of the results curves of velocities, which depend directly on the duration of pregnancy.
In most cases, women with abnormal Doppler is performed in the 32nd week, because at that time the placenta already formed, appointed a caesarean section will save the life of a baby. For example, in the normal range, the value VC of the aorta of the fetus for a period of 32 weeks is from 24.3 to 60.26.
This procedure allows the technician to objectively draw conclusions about the health of the baby, identify existing pathology and to know the exact reason for their development, which will definitely help him to properly and effectively prescribe treatment. For example, such pathologies as hypoxia, can occur not only due to entanglement neck of the baby by the umbilical cord, but also because of impaired blood flow the uterine arteries, the umbilical cord and the fetus.