Types of ultrasound during pregnancy, features of their implementation, indications, goals - you will learn about this (and more) from the article. What they have in common is that ultrasound, which helps to obtain a wide variety of information, is harmless and painless for the fetus, especially if the research is approached wisely.
Purposes of ultrasound
According to the purpose of the information received, ultrasound diagnostics is divided into:
- screening studies (this includes ultrasound of pregnant women). Their goal is to identify a risk group for various pathologies, which will require further examination by more specialized specialists
- selective diagnostics. These are precisely those “additional examinations” when the doctor carefully identifies the nature of the pathology and its impact on the function of the fetus as a whole. Based on such data, the choice of further tactics for pregnancy and delivery is made.
Based on the nature of the information received and the method of obtaining it, the following types of ultrasound during pregnancy can be distinguished:
- transvaginal ultrasound: it can be both selective and screening
- examination performed through the anterior wall of the abdomen (abdominal ultrasound)
- Volumetric diagnostics are the so-called / ultrasound.
Some sonologists also distinguish fetal fetometry as a separate study. But usually fetometry, that is, measuring the size of different parts of the fetus, is carried out as a mandatory part of screening or selective studies.
This means that in order to find out the consistency of height, weight, bone lengths and cavity diameters, a woman does not undergo any separate examination - she is given such a conclusion during routine or control ultrasounds. It does not matter in what way - transvaginal or abdominal - this study was carried out.
Below we will look at how and why each type of ultrasound diagnostics is performed.
Why do you need instrumental monitoring of pregnancy?
Ultrasound diagnostics of pregnancy is performed in order to know how the fetus develops, how the maternal organs perform their functions, as well as the placenta, amniotic fluid and umbilical cord. Survey data helps:
- determine the timing of pregnancy
- calculate the approximate due date
- find out the number of fetuses, their location and presentation
- find out where the placenta is and how it functions
- detect developmental abnormalities in time
- diagnose pathology of the placenta and umbilical cord
- establish the volume of amniotic fluid
- determine how chronic or acute diseases mother, whether the baby suffers from lack of nutrition and oxygen.
Screening ultrasound during pregnancy has its own timing; it is required to be performed three times during the entire period, provided that the pregnancy is normal - one in each trimester.
Detailed characteristics of each type of ultrasound diagnostics
1. Transvaginal method
It is also called intravaginal ultrasound. It is usually used only in the first trimester, up to 12 weeks, only as prescribed by a doctor.
It is more informative than the one done through the abdomen in terms of diagnosing pregnancy on early stages. This study also reveals pathology of the placenta and cervix better than its transabdominal counterpart.
This happens because ultrasound creates Better conditions to penetrate into the pelvic cavity: the sensor is separated from these organs only by the vaginal wall. Therefore, such a study is called internal ultrasound during pregnancy.
There is no need to prepare for this diagnosis, other than toileting the genital organs. Before the examination, you need to empty your bladder so that it does not interfere with the ultrasound and does not cause you discomfort.
2. Prenatal screening
Genetic ultrasound during pregnancy is a study usually carried out in conjunction with biochemical screening, that is, a blood test for hormones, changes in the level of which are a marker of chromosomal abnormalities.
Such a study is carried out by a sonologist who works in a medical genetic center as a specialist in prenatal diagnostics. 
It differs from a “regular” ultrasound in that the doctor performs an examination, specifically focusing on identifying the smallest developmental anomalies that may be invisible to the untrained eye.
This study is carried out using the latest model scanners, which is why it is also called expert-class ultrasound. It can be performed either transvaginally (usually the first prenatal screening is performed this way) or through the abdomen.
The latter option, together with the mandatory use of Doppler measurements, is performed in the second, and, if indicated, in the third trimester.
3. Doppler
This is what is called a pregnancy blood flow ultrasound. Such an examination is carried out on special devices that are equipped with a program mode that can evaluate the qualitative and quantitative characteristics of blood flow. The sensors used for Doppler measurements can be designed for both vaginal and abdominal examination.
Doppler testing is performed both as part of prenatal screening and as an independent study at different times.
Conducted transvaginally at the 5th week, and abdominally at the sixth week, Doppler will help determine the viability of the fetus by determining its heartbeat. Closer to week 20, such a study helps to exclude or confirm heart defects. And starting from the 28th, Doppler testing is aimed at diagnosing oxygen starvation of the fetus.
4. Cardiotocography
This study, like Doppler, is aimed at diagnosing fetal hypoxia. But if, with Doppler measurements, this condition is judged on the basis of the patency and resistance of the walls of blood vessels, the speed of blood flow in them, then CTG is a functional method.
In this case, ultrasound records the fetal heartbeat in a calm state, and also notes changes in their frequency depending on its movements and contractions of the uterus.
5. Volumetric study
This type of diagnosis has a second name - color ultrasound during pregnancy, as well as 3 or 4D examination. It allows you to see a three-dimensional image of your child. In this case, it will be colored (usually golden).
Such a study will help doctors better understand how tightly the umbilical cord is entangled, and whether there is a malformation of the face or limbs. Parents, even without the doctor’s prompting, will be able to make out what they see on the monitor. And without any help they decipher images from ultrasound during pregnancy.
Answers to questions about ultrasound diagnostics
Designation of the main abbreviation when decoding
What is CTE on ultrasound? This abbreviation denotes the coccygeal-parietal size, that is, what later, with the advent of full-fledged limbs, will be called the child’s growth. This size in the first trimester is used to judge the gestational age of the fetus. After the 16th week, it is no longer measured, using other indicators to assess the duration and uniformity of fetal development.Bone pathology associated with the "interesting period"
Ultrasound of the pubic bone during pregnancy. In most cases, when signs of symphysitis occur (pain above the pubis, changes in gait, palpation with discrepancies between the bones of the pubic joint), ultrasound is rarely informative.Sometimes ultrasound “sees” symphysitis during pregnancy. It looks like a widening of the gap between the pubic bones. In this case, thanks to ultrasound of the symphysis pubis, it is possible to determine the tactics of delivery: if the fetus is not large, the size of the pelvis is normal, and the discrepancy of the bones is less than 10 mm, there are no indications for cesarean section.
When is diagnosis carried out after abortion?
Ultrasound after medication interruption pregnancy is indicated for all women. It is advisable to undergo it within two weeks after the abortion to exclude the possibility that elements of the fertilized egg remain in the uterus. Because of this, heavy bleeding may occur after a medical miscarriage.
Unscheduled ultrasound examinations
This is called a “control ultrasound during pregnancy.” It is carried out for various pathologies of pregnancy so that the doctor knows what treatment and regimen to further prescribe to the woman. The timing of such a study is chosen by the doctor himself.
So, for example, if there was bleeding that stopped after strict bed rest, partial placental abruption occurred. In this case, an ultrasound is performed with a portable scanner (in the ward), and control is carried out with the same scanner a week later.
Depending on what the sonologist sees, the woman is allowed to either gradually expand the regimen, or is left to lie there for a while longer. 
Cervical examination
Ultrasound of the cervical canal during pregnancy is especially important in the diagnosis of isthmic-cervical insufficiency. This study helps evaluate:
- width of the cervical canal (about 7-8 mm)
- cervical length (normally about 40 mm)
- mucus plug condition
- state of the internal and external pharynx (open or closed)
- the presence of polypous growths in the cervix.
Where to get ultrasound diagnostics
There are many clinics and prenatal centers where they do good ultrasounds during pregnancy. Medical-genetic or prenatal centers, where prenatal diagnostic specialists work, deserve special trust.
Therefore, to choose a clinic where you will undergo an ultrasound scan during pregnancy, it is advisable to check with your gynecologist whether there is a sonologist whom he has recommended. And since one doctor often works in several centers, make inquiries about this and decide where it will be more convenient for you to undergo the study.
The cost of ultrasound during pregnancy depends on the type of examination and the stage of pregnancy. Thus, a study of the first trimester costs about 1,300 rubles, while the second and third – about 1,700 rubles. A volumetric study costs about 3,000 rubles. Dopplerography costs about 1,200 rubles, CTG costs about 1,000 rubles.
Thus there are different types Ultrasound during pregnancy. Each of them is necessary and useful in its own way, each has its own indications and decoding features.
Currently, nothing more effective than the ultrasound method has been invented to monitor the development of pregnancy. This type of procedure is mandatory for all pregnant women, regardless of whether the pregnancy is normal or with pathologies. The only difference is that those pregnant women who have problems with this condition experience it much more often.
However, when prescribing an ultrasound, you can get confused by the names of the study itself. Ultrasound examination is the general name for a number of medical procedures. Their goal is the timely detection of pathologies, defects, threats, placental functions, and the volume of amniotic fluid. Even when the diagnosis does not give such rosy results, the observing gynecologist has time to prescribe effective treatment.
Many pathologies can be cured even before childbirth. Otherwise, the risks of developing serious conditions will be minimized. Pathologies and the development of pregnancy can be determined using the following types of ultrasound:
- Types of pregnancy ultrasound are divided into screening ones, which are aimed at identifying defects, pathologies and anomalies. If the results are unsatisfactory, then repeated diagnostics are carried out using ultrasound, and additional tests are prescribed.
- In addition, types of pregnancy ultrasound include selective methods. They are additional examinations that observing gynecologists can prescribe in case of deviations. Selective methods help to accurately determine the nature of pathologies. Based on the results of selective diagnostics, treatment and methods of delivery are prescribed.
The following types of pregnancy ultrasound will help you obtain information:
- Diagnostics using modern 3D and 4D volumetric examinations.
- Doppler study
- Cardiotocography
- Abdominal and transvaginal ultrasound of pregnancy
Main types of ultrasound data acquisition
Volumetric three-dimensional ultrasound is also called color ultrasound. Its advantage is that during the diagnostic process you can enjoy a realistic image of the fetus. Typically, color examination shows the fruit to be golden in color.
Doppler on ultrasound pregnancy shows the functioning of the blood flow system. A conventional ultrasound diagnostic apparatus is not used for Doppler measurements. It must have a special program installed on it that allows for a qualitative assessment of all parameters of the circulatory system. Doppler is used to assess the fetus, uterus and placenta. This type of ultrasound diagnostics is used for abdominal and transvaginal examinations.
The observing gynecologist can recommend Doppler ultrasound at any time, if the need arises. In the early stages, diagnostics will determine the cardiac activity of the fetus, excluding frozen pregnancy. Later dates refute or confirm defects of the cardiac system. Closer to the delivery date, Doppler detects a lack of oxygen in the fetus.
Cardiotocography or CTG very similar to a Doppler study. Its purpose is to detect oxygen deprivation. This happens by recording the calm fetal heartbeat in combination with changes occurring in the uterus. If the gynecologist considers that this examination is necessary, you should not refuse it.
Transvaginal ultrasound during pregnancy - this is the very first ultrasound that is performed. To do this, the sensor is inserted into the vagina. Thanks to its closest location to the uterus and the fertilized egg, the diagnostic device will more accurately determine the presence of pregnancy, its timing, the presence and nature of pathologies of the fetus and placenta, if any.
The second name for this type of diagnostics is internal. It is carried out only with an empty bladder. This will remove all interference that will block the sensor from the organs being examined. There is a significant limitation - diagnosis is carried out exclusively in the early stages of pregnancy, before the 12th week, which refers to the first trimester.
Abdominal ultrasound view - This is a study through the abdominal wall. In other words, the sensor is moved across the abdomen. This diagnostic is used for later. The second and third studies are carried out in this way, since the fetus is already large enough and the sensor will determine everything that is necessary.
In addition, there is prenatal screening or genetic testing. Often this type of diagnosis is combined with biochemical screening. During the ultrasound examination, the specialist will pay attention to all abnormalities of fetal development. It is important to choose a good diagnostician who will be able to notice the slightest deviations from the norm.
The ultrasound procedure has become quite popular in a fairly short period due to its maximum information content during gestation. Are used different kinds ultrasound during pregnancy. Some methods have become mandatory and are carried out according to plan, while other types of research are used only if indicated.
Mandatory screening ultrasounds
Ultrasound examination involves the use of ultrasonic waves, which are reflected from tissues and, thanks to modern equipment, are converted into an image on the monitor screen. During the study, the frequency of the waves can be adjusted, which allows the lowest rates to be used during pregnancy.Due to the fact that the absolute safety of ultrasound for pregnant women has not been proven, doctors try to minimize the ultrasound effect on intrauterine development. Therefore, during the entire gestation period, only three mandatory, planned studies are used:
- at the beginning of the 2nd trimester (11-13 weeks);
- at the end of the 2nd trimester (20-24 weeks);
- before childbirth (30 – 34 weeks).
- The transvaginal method is a type of ultrasound that is done to determine pregnancy at the earliest stage of gestation. During the examination, an ultrasound sensor is inserted into the vagina, since this is the method that will allow you to obtain maximum information about the condition of the pelvic organs, starting from 3 weeks after conception.
- The abdominal method is considered the most traditional, in which the sensor is moved along the anterior wall of the peritoneum or along the abdomen. The study is used in all planned ultrasounds and allows you to take all the necessary measurements of the fetus, and then compare them with existing standards.
To clarify the diagnosis, if the development of pathology is suspected, additional unscheduled ultrasound examinations, for the purpose of timely detection of the disease and the use of drug therapy.
Ultrasound with Doppler during pregnancy
Doppler measurements become most informative in the third trimester, with specialists assessing the quality of blood flow between the expectant mother, the placenta and the baby. During the examination, an ultrasound device shows a graph of blood flow through the arteries due to the reflection of ultrasonic waves from red blood cells.There are two types of Doppler ultrasound that are used during pregnancy:
- the duplex method involves studying the movement of blood in the arteries in monochrome color;
- The triplex examination method shows blood flow in the uterine cavity in color, which is most effective for assessing the child’s breathing and nutrition.
Doppler ultrasound becomes most indicative at 30-33 weeks and is often combined with routine screening ultrasound. To confirm the diagnosis, ultrasound with Doppler is prescribed earlier than the third trimester, but not earlier than the 20th week of gestation.
Cardiotocography during pregnancy
In the normal course of pregnancy, CTG is used at 30-32 weeks to assess the fetal heartbeat; changes in frequency are noted depending on the activity and contractions of the uterine cavity.During the cardiotocography procedure, several sensors will be installed on the woman’s stomach, and it will be enough to take a lying position and relax as much as possible. CTG takes about 40 minutes, during which time the frequency of the heart and uterus is recorded. The diagnostic method is considered absolutely safe and does not harm intrauterine development.
The main goals of CTG are to exclude hypoxia in the baby and the absence of uterine hypotension, the provoking factor of which is placental abruption, gestosis, umbilical cord entanglement or various pathological conditions.
Volumetric ultrasound studies
At the present stage of development of medicine, three-dimensional types of ultrasound during pregnancy are used, which use 3D technology. There are two types of examination:- with 3d ultrasound, the baby is presented on the monitor screen in a 3-dimensional image, taking into account height, depth and length;
- with 4d ultrasound, a fourth dimension is added - time, which not only visualizes the image, but also creates a video effect when the image moves in real time.
There are several other reasons - purely individual ones - for which a doctor can send a pregnant woman for an unscheduled ultrasound.
Types of ultrasound during pregnancy
Today there are three types of ultrasound during pregnancy.
2D ultrasound – ultrasound in only two dimensions: width and height. The picture is obtained in the form of a black and white photograph. In terms of time, such an ultrasound lasts 15=20 minutes.
A 3D ultrasound is a high-quality three-dimensional color image: you can even see the baby’s facial expressions on it. Time: 50 minutes.
Ultrasound 4D – three-dimensional image. With such an ultrasound, the baby can be seen in motion and even recorded on a video recording medium.
How is an ultrasound performed during pregnancy?
Ultrasound during pregnancy does not require any preliminary procedures: you do not need to fast, as during an examination of the gastrointestinal tract, or drink a lot, as during an ultrasound of the bladder. But before the study, it is advisable to take a disposable diaper and napkins with you. You will lie down on the diaper and wipe off the remaining gel on your stomach with napkins. By the way, the gel is needed so that on the monitor ultrasound machine an image appeared. You don’t need to hope that everything will be given to you in the ultrasound room - these things are not there, unless in a private clinic all this is provided to patients.
There are two types of sensors for ultrasound examination:
- Abdominal
- Vaginal
The abdominal sensor is moved along the abdomen, and the vaginal sensor is inserted into the vagina, while a condom is used. The last sensor is used in the very early stages of pregnancy, when you need to confirm it or, conversely, refute it. The abdominal sensor can be used throughout pregnancy.
It should also be noted that expectant mothers, when going for an ultrasound, are always worried about how this procedure will go and what results await them. Of course, there is no need to worry. Firstly, this will harm your baby, because all the experiences of his mother are transmitted to him, and secondly, any violation that the ultrasound shows can be eliminated later. Therefore, it is important to visit the office where an ultrasound is performed in a timely manner, following all the doctor’s recommendations. First of all, your baby and you need this, so only you should take care of his and your health.
Women undergo an ultrasound scan in the early stages of pregnancy to exclude possible pathologies of fetal development and determine sex. There are different types of ultrasound during pregnancy, which in each specific case depends on the situation. In total, you need to do 3 main procedures at different times during this period.
Ultrasound during pregnancy can identify pathologies of fetal development
General characteristics of the examination
The gynecologist who will care for the pregnant woman until the moment of birth will tell you how much and how often you need to be examined. If this period proceeds without problems, illnesses or other unpleasant symptoms, the doctor will prescribe only 3 procedures. They are planned and absolutely safe for both the health of the mother and the baby.
Ultrasonography is considered an informative method for determining pregnancy and possible pathologies. During the procedure, a device consisting of a monitor, a system unit and a sensor sends high-frequency ultrasound signals deep into the body. They bounce off the surfaces of soft and bone tissues, as well as blood vessels. But only part of these signals returns back to the sensor, which is converted by the computer into an image, while the rest remain in the pregnant woman’s body.
There are 3 types of ultrasound during pregnancy:
The main purpose of the study in the early stages of pregnancy is to determine age, the number of fertilized eggs and identify abnormalities and ectopic development of pregnancy. If the baby develops with obvious abnormalities that are incompatible with life, doctors can inform the woman about this and offer to terminate the pregnancy at an early stage. In addition, the diagnostician is obliged to warn the gynecologist about problems that require urgent intervention:
Types of examination
To provide a woman with the most comfortable pregnancy possible, doctors perform prenatal screening. This is not one study, but a whole complex. It consists of ultrasound and biochemical examination. The procedure consists of 3 parts:
These ultrasound dates during pregnancy should be strictly observed, because each of them provides certain information that is important at this stage of bearing the baby. An ultrasound in the first month of pregnancy is not informative if a woman becomes pregnant naturally. Since the fertilized egg is still very small, the diagnostician will not be able to see it. The embryo has not yet fully formed, and the sex of the unborn baby is not visible. Such a study is mandatory if a woman has in vitro fertilization.
In order to monitor a woman and be sure of her pregnancy, a doctor must prescribe such a procedure from 21 days after fertilization. The manipulation is carried out using special vaginal sensors, which the physician inserts through the patient’s vagina. This way, the diagnostician will be able to better verify the correct attachment of the fertilized egg, and at this time an ectopic pregnancy will be excluded.
Ultrasound in early pregnancy is performed with a vaginal sensor
Diagnostics in the first month only confirms the fact of conception and fertilization; the first ultrasound during pregnancy should be scheduled at 9-12 weeks. Exceptions are the following symptoms:
- Bloody issues.
- Pain syndrome in the lower abdomen in combination with delayed menstruation.
- Habitual miscarriage to exclude the possibility of lack of development.
- Mismatch between fetal size and term.
- Multiple pregnancy.
Ultrasound can diagnose multiple pregnancies
Second three-dimensional picture future mom will receive at 20 weeks. It needs to be done to analyze the anatomy of the child’s systems and organs. Particular attention is paid to the central nervous and cardiovascular systems. There are cases when a woman is examined earlier than this period to clarify gross defects and developmental anomalies, then she still needs a three-dimensional ultrasound during pregnancy during this period.
Ultrasound in late pregnancy is the third examination that provides information about the presentation of the fetus. This manipulation is carried out at 32 weeks.
It is very important at this time to undergo a Doppler ultrasound during pregnancy, which carefully examines the curves of the blood flow plane of the fetal vessels, as well as other features of its development and functioning. Such a diagnosis will prepare the obstetrician-gynecologist for a possible scenario for the development of labor and the last days of a woman’s pregnancy.
The last scheduled ultrasound is performed at 32 weeks of pregnancy
Indications for use
In some cases, women who are at least 1 day late are referred for examination. This is justified if there is a risk of developing ectopic pregnancy. This period corresponds to the third week.
When a woman feels the birth of a new life within herself, she first runs to the pharmacy for a test. After 2 stripes appear on it, she goes to the gynecologist, who does an examination. Based on visual indicators and the results of the inspection, he determines the approximate period. If it is less than 12 weeks and there are no pathologies or suspicions of abnormal development, the woman is given a referral for examination in the first trimester.
The doctor will definitely prescribe an ultrasound during pregnancy at 10 weeks in the following cases:
In other cases and with normal development, the examination is done at the twelfth week. Your attending physician will explain in detail what kind of examination you need to undergo. A routine ultrasound at 12 weeks of pregnancy should be performed in the following cases:
- Confirmation of the fact of conception and determination of the due date.
- Identification of possible pathologies of the uterus, fetus or placenta.
Ultrasound examination can exclude ectopic pregnancy
The second ultrasound during pregnancy allows you to determine the sex of the fetus, so many women look forward to this examination with special impatience. Indications for such diagnostics at this stage of development are the following symptoms:
- Any discomfort or pain in the lower abdomen.
- Lack of fetal growth.
- Any discharge.
- The woman did not feel fetal movements after 20 weeks.
- For viral or infectious diseases.
An ultrasound is prescribed as an emergency if a woman does not feel fetal movement after the 20th week
Often during this period an ultrasound is performed during pregnancy using Doppler. If there are reasons for terminating pregnancy, the law allows all these manipulations to be carried out up to 22 weeks. The third scheduled examination is carried out at 32 weeks of pregnancy. Indications for unscheduled examinations during this period:
- problems with development or failure to meet deadlines;
- lack of movement;
- premature birth;
- if contractions began earlier than the third scheduled examination.
For an unscheduled scan of the state of the ovum, the following symptoms or developmental problems are needed:
Contraindications to the procedure
Many women are worried and begin to harass doctors with questions about whether it is harmful to carry out such diagnostics, whether ultrasound can harm the baby and how many times it can be done. There is a part of people who consider the influence of the diagnostic method to be negative on the child’s health. They explain this by heating the tissues, as well as the formation of bubbles in the fertilized egg, which in the process burst and harm the baby’s organs and systems. But after conducting more research, scientists have determined that ultrasound has no harmful effects on the fetus.
Ultrasound examination does not have a negative effect on the fetus
Therefore, all questions can be answered unequivocally: such a procedure does not harm either the mother or the child, but it should not be carried out thoughtlessly. For example, such a study is necessary during pregnancy after IVF, but during a normal course, you should not prescribe unscheduled procedures without proper indications.
3D ultrasound is not a routine, but only an additional diagnostic method. Its advantage is the three-dimensional image, which shows a beautiful picture, very similar to a photo of a child. In addition to such an accurate image, parents will be able to look at the movements of the fetus in real time and consider its gender, which is often the purpose of such a visit.
The doctor writes down the analysis of all indicators in a special protocol, and outputs the photo to a printer; the baby’s movements remain on the disk. Thus, ultrasound manipulation allows you to obtain as much information as possible about the unborn baby without harming the body.
3D ultrasound allows you to get a detailed image of the child
Preparation for the procedure
To do a fetal ultrasound, a woman does not have to take special care. This process largely depends on how many weeks have already passed. Therefore, a pregnant woman should switch to a special diet without foods that form gases at the very first abdominal ultrasound. Transvaginal examination does not require special preparatory steps, as does the procedure for diagnosing the fetus at 32 weeks.
How is the examination carried out?
The attending gynecologist will tell the woman how many times an ultrasound scan needs to be done during pregnancy. During the first scan, the sensor can be placed either on the abdomen, having previously lubricated it with gel, or by inserting special equipment through the vaginal opening. In the latter version, a detailed situation of fetal development is visible, which makes it possible to accurately determine pregnancy.
To do this, a woman must expose her lower part and, lying on her back, bend her knees. The medic will make gentle movements in different directions. A doctor will be able to determine the sex only during the second scheduled diagnosis, because it was during this period that the fetus was sufficiently mature.
At the second ultrasound, the woman is usually told the gender of the baby.
After such manipulation it is possible side effects. Doctors admit the appearance of scarlet lungs yellow tint discharge that will soon go away.
How often should an ultrasound be performed during pregnancy, watch the video:
