Ultrasound (3D, 4D): know the types and when to do

High frequency sound waves and their propagated echoes are responsible for what we know today as ultrasound, or just ultrasound. The procedure is an image exam that allows the diagnosis and prevention of diseases to various medical specialties.

This is also the technique responsible for curing the curiosity of parents who wait for a baby and who do not want to wait 9 months to know the child’s biological sex.

Even in the world of beauty, these waves have their space, helping, for example, to soften cellulite and localized fat.

When we talk about these benefits of ultrasound, we refer to the most current and developed use of the technique – which is not new.

Much has evolved since the 1950s, when the patient remained immobile and immersed in water tanks to be able to perform the ultrasound, until we reach the devices used today.

And it is not only in health that high frequency waves are applied, as it is interesting to highlight the importance that ultrasound had in historical episodes, as in the well-known sinking of the Titanic or during the First World War.

In the case of the ship, the use of ultrasound was done to help detect submerged objects. In the First War, the technique was used as a defense strategy, contributing to the location of submarines from enemy countries or icebergs.

In the text that follows, we will describe how technology contributes to health and how it works. But, rest assured, to understand it, it will not be necessary to study Sound Theory or go deeper into the concepts of modern acoustic physics. In practice, the exam is simpler than it looks. Good reading!

What is ultrasound?

Ultrasound, also known as ultrasound or ultrasound, is an image exam done to view a specific tissue or organ in the body in real time , facilitating the diagnosis of diseases and other conditions.

Among the test recommendations, one of the most common is its use during pregnancy, prenatal care and throughout pregnancy. In this case, it aims to monitor the development and the tracking of diseases in the newborn, in addition to allowing the identification of biological sex – one of the great curiosities of parents during this period.

The procedure is quick and the patient’s preparations are simple, and the examination is carried out in clinics, laboratories or hospitals.

In general, this is a technique used to generate images through high frequency sound waves (ultrasound) and their echoes, which are not audible to humans.

These sound waves pass through the organism or body tissue and their echoes are “heard” by the computer, transforming these signals into images (photos or videos).

As it allows differentiation of different tissues and organs of the body, which is only possible due to the variation in density and components that it presents in its structures, ultrasound is quite versatile and can help different health specialties.

How does it work?

To understand how ultrasound works it is necessary to remember physics classes a little.

There are two types of waves: electromagnetic waves, which do not need a means to propagate; and mechanical waves, which need a means to propagate.

In the case of ultrasound, which is a mechanical wave, propagation occurs through our biological tissues. With the use of a device called a transducer, sound waves – which are inaudible to humans – are emitted in the analyzed region.

These waves pass through the area of ​​the body through which the transducer is pressed and propagate in waves that are reflected, thus creating an image on the screen of the ultrasound device in real time.

The way ultrasound works is similar to the echolocation process of some animals, such as dolphins and bats. This echolocation is a biological skill that allows these animals to perceive the distance and position of other animals and objects from the emission of ultrasonic waves.

Whether in the air or in the water, the animals have the ability to analyze the time needed for the emission and reflection of these waves, like an echo.

In short, this is how ultrasound works in theory (and in practice), but from the way it is performed it seems much simpler.

The exam is painless and does not require much preparation to be performed. It is usually done within the ultrasound or radiology department of hospitals and specialized clinics.

During the procedure, the patient usually remains lying down and the doctor uses a specific gel to help guide the transducer over the region to be evaluated.

This gel is important to prevent the air present between the device and the patient’s skin from damaging the sound waves, in addition to helping the device to slide better over the skin, as it is also a lubricating gel. By passing the transducer over the body surface, the doctor can observe the images in real time, which helps to achieve a more accurate diagnosis.

What is the ultrasound exam for?

Ultrasound is done to help diagnose diseases related to Organs reproductive organs, glands, joints, muscles, tendons or any other part of the body.

It is also performed to monitor the baby’s development during pregnancy, allowing the investigation of clinical complications or to find out if it is a boy or girl.

In addition to being used in medicine, ultrasound is also used in aesthetics, in procedures that help to reduce measures or for the treatment of cellulite, for example.

Thus, the use of ultrasound can be divided into three main purposes:

Gestational follow-up

Ultrasound for pregnant women is a common exam and can be done every quarter. It is asked to monitor the baby’s health, to analyze whether it is developing as expected and to track possible complications.

It is also done for parents to know a little more about the baby, as the test allows you to hear the heartbeat, know its sex and, depending on the type of ultrasound, even some features of the face.

Disease diagnosis and prevention

Ultrasound is a fundamental image exam for the prevention and diagnosis of a series of pathologies, used by specialists from different medical fields.

It can be used to analyze possible thyroid problems, endometriosis and cardiovascular diseases, for example.

Physiotherapeutic or aesthetic treatment

Ultrasound can also be used to treat certain conditions. When used as a therapeutic treatment, it contributes to the reduction of muscle pain, healing and fracture recovery. In aesthetics, ultrasound helps to reduce cellulite and localized fats.

What is the ultrasound transducer?

The ultrasound transducer is the device used during the examination and works as a kind of camera to capture images for diagnosis. It is responsible for emitting waves by transforming voltages into vibration, thus forming images.

The models vary according to the examination performed, being divided as follows:

  • Linear : with a straighter structure, this type of transducer is more used for examining superficial and external organs, such as breasts, testicles, tendons, skin, thyroid, etc;
  • Convex (curved) : it is a type of transducer with curved structure, which allows a better examination of the kidneys, ovaries, heart, fetus, uterus, gallbladder, liver, etc;
  • Endocavitary : allows the performance of internal ultrasound or cavities, as in gynecological exams. It can also be used to view the esophagus, respiratory tract or in surgery;
  • Cardio : specific for cardiac exams, the model is more sensitive, as it allows better perception of blood flow and heart movement;
  • Sectorial : it is also used for examining internal organs, such as neurological and cardiological organs;
  • Special : they have some kind of technology besides the ones mentioned, that allow to obtain 2D images (biplane), as it is in the other types, but also the baby’s visualization in three different angles (3D) and in movement (4D).

In addition to these transducer variations, there are also applications that allow certain assessments in exams:

Elastografia

When present in transducers, this application is used to assess the elasticity of tissues, such as the liver, thyroid and breasts, for example.

Elastography is a technology that allows the assessment of tissue stiffness, which is important for the diagnosis of diseases such as hepatitis C , as it allows the analysis of liver fibrosis caused by the condition. The greater the fibrosis, the greater the tissue stiffness and this can be diagnosed with the help of ultrasound.

Doppler

It provides greater perception of blood flow, being a common resource to most transducers and applied in several areas of medicine, such as obstetrics, cardiology, hepatology, nephrology, among other specialties.

Widescreen

It allows the reach of wider planes, allowing the visualization of areas larger than that obtained with conventional transducers.

Contrasted

It allows the evaluation of tissue perfusion by providing a contrast through the bloodstream. It is most used for the diagnosis of cardiovascular diseases.

Exam types

This test is divided into some types, depending on the region diagnosed and according to the clinical condition being investigated. Know the main ones:

Transvaginal ultrasound (endovaginal)

Transvaginal ultrasonography, also known as endovaginal ultrasound , is an exam done to visualize the internal organs, such as the fallopian tubes, ovaries, uterus, cervix and the vaginal canal.

Usually, this type of examination is requested by gynecologists to diagnose diseases related to the organs of the female reproductive system.

Through ultrasound it is possible to observe the presence of infections, cysts, diagnose some types of cancer , ectopic pregnancy or to confirm a pregnancy.

It is a safe and painless examination, done through the use of an endocavitary transducer. During the examination, the woman remains lying down and the doctor introduces a condom to cover the device and uses a little lubricating gel. The device is inserted into the woman’s vaginal canal and the images are viewed in real time.

Transrectal ultrasound

Usually, this type of ultrasound is done for the diagnosis of prostate cancer , in men who, during the digital rectal exam , observed an abnormality or who have high levels of Specific Prostatic Antigen (PSA).

During the procedure, a lubricated probe is inserted into the patient’s rectum and from there the images emitted by the echoes of the sound waves are captured and transformed into images on the device’s screen, just as it works on other types. It is a painless exam and lasts, on average, 10 minutes.

Transesophageal ultrasound

Transesophageal echocardiography is a type of ultrasound, which is done by inserting a tube into the esophagus, with the patient under the effect of local anesthesia, to prevent nausea or vomiting. The images are captured from the transducer located at the tip of the probe, usually introduced with lidocaine spray (painkiller) and gel.

It is a procedure done to analyze possible changes in the functioning or structures of the heart.

It can be performed in cases of suspected systemic and pulmonary embolism, to view malformations, valve prostheses, endocarditis , aortic diseases and other conditions related to the vascular system.

Pelvic ultrasound

Unlike what is done in transvaginal ultrasound, in this type the doctor uses the transducer device in the external area of ​​the pelvic region.

However, the goal is similar. This is also an examination done on women to look at structures such as the ovary, uterus and blood vessels in the region, usually requested by the gynecologist.

To be performed, it is necessary that the patient has a full bladder. Generally, they should avoid going to the bathroom for up to 2 hours before the exam, consuming enough liquid, so that the ultrasound can capture clearer images.

Total abdominal ultrasound

Total abdominal ultrasound is an examination that allows the observation of several organs in this region, usually done to investigate the cause of abdominal pain, observing the organ structures, anatomical changes, the presence of tumors or abnormalities.

Able to produce images of the pancreas, liver, kidneys, spleen, bladder and gallbladder, the test can capture solid or liquid-containing organs, although it is not the best option for regions filled with air, such as stomach and intestine, as the gases impair the examination.

Breast ultrasound

Breast ultrasound is an examination performed to help diagnose and prevent breast cancer . It can be requested by the gynecologist or mastologist, when they feel the presence of a lump during palpation of the breast, in cases in which the mammography was not conclusive or in women who have a family history of the disease.

During this examination, the woman lies on her back and with her arms behind her head. Then, the doctor applies the gel to the breast area and lightly presses the transducer on them.

Generally, it is not necessary to perform an ultrasound with the woman on her stomach, only when she has larger breasts. Thus, the examination becomes more complete.

The procedure is simple and usually lasts between 15 and 30 minutes. With the exception of women who have hypersensitivity in the breast region, this type of ultrasound does not cause pain.

Despite being a good test to confirm the presence of nodules, it is not the most suitable for the early diagnosis of breast cancer, because depending on the size of the nodule, it may not be possible to visualize it.

Ultrasound of the thyroid

The thyroid is a gland located in the neck region, below the Adam’s apple, responsible for the production and secretion of the hormones T3 and T4, triiodothyronine and thyroxine, active in the regulation of metabolism.

It interferes with the action of various functions of the organism and when it presents an irregular hormonal production, some complications can occur, such as hyperthyroidism and hypothyroidism , for example.

In thyroid ultrasound, it is possible to observe if there are variations in the size and shape of the gland, in addition to allowing the investigation of the presence of nodules. It is an important test to check the need for a biopsy, for example.

The procedure is simple and the patient remains lying down, with the neck extended and with the chin raised, leaving the throat region well exposed. After passing the lubricating gel in the region, the transducer is moved over the skin surface to obtain the images.

Morphological and obstetric ultrasound

Both refer to exams during pregnancy, but for different phases or periods. Although the name is not so familiar, morphological ultrasound is well known by pregnant women. It is done with the objective of investigating if everything is fine with the baby’s health and if its development is occurring within the expected.

Usually, at least three ultrasound exams are performed during pregnancy, performed each quarter. As it is only possible to feel the baby move from the 4th month of gestation , this exam done in the 1st trimester also serves to make the pregnant woman more relaxed, knowing that everything is fine with her baby.

Depending on the baby’s position, it is now possible to identify his biological sex.

In the examination, the woman should lie on her back and with the upper back more elevated. With the belly lubricated with the transparent gel (water-based), the doctor must pass the transducer over the abdominal surface to capture the images.

There are some differences, depending on the quarter in which the exam is taken:

1st quarter

In the 1st trimester of pregnancy, the ultrasound can be called an obstetrical ultrasound. The doctor requests it for several reasons, such as to be able to date the pregnancy, see the growth of the fetus, evaluate the umbilical cord, placenta, amniotic sac and the baby’s anatomy.

In addition, it allows assessing the pelvic region, the presence of gestational diseases, ectopic pregnancy or cases of abortion.

2nd and 3rd quarter

In the 2nd and 3rd gestational trimester, the woman is submitted to this exam so that conditions such as malformations, fetal growth (to see if it is too small or too big), vitality and also to monitor the progression compared to previous exams.

It also allows you to view most of the baby’s structures, such as the head, spine, external genitalia, lower and upper limbs, chest and neck. To see the baby’s face, for example, 3D ultrasound can be done.

When done in the second trimester, the exam is usually performed between the 20th and 24th week. In the third trimester, it is done between the 28th week and the 32nd week, close to the end of pregnancy.

3D and 4D ultrasound

These types belong to a more advanced ultrasound model because they allow the visualization of a more real and detailed image of the analyzed region. In the case of 4D ultrasound, for example, it is also possible to better identify movements, which is widely used in exams performed on pregnant women, obtaining a more detailed image of the organ, tissue or baby.

Usually, this type of ultrasound (3D and 4D) is indicated for pregnant women, being more recommended for the 26th or 29th week of pregnancy, as the baby is already more developed and there is a good amount of amniotic fluid in the woman’s belly, making it easier the capture of images.

Before that, the baby is still very small and the procedure may not be as effective. As of the 30th week, the baby already occupies a very large space, leaving the image less clear.

In addition to the gestational week, other issues can influence the result, for example:

  • When the baby is positioned with his / her back to the mother’s belly, preventing the visualization of his / her face;
  • When the baby has the umbilical cord or one of the limbs positioned in front of the face;
  • When there is an excessive amount of fat in the mother’s abdominal region, as they make it difficult for the ultrasound waves to form the image;
  • When there is not enough amniotic fluid, because the more fluid you have, the better the images obtained on the exam.

Ultrasound in pregnancy

Ultrasound in pregnancy ( morphological ultrasound ) is the most well-known type of ultrasound examination. It is done to monitor the baby’s development and to investigate conditions such as anencephaly, hydrocephalus , Down syndrome and other possible variations presented by the baby.

Read more: Stretch Marks in Pregnancy: types (red), best cream, how to avoid?

Because it is possible to measure the head, the doctor can investigate whether there is a serious malformation problem in this baby’s structure. In addition, it can analyze whether the bones are well formed and aligned (especially those of the spine) and whether the heart is developing properly.

In general, the doctor should observe the formation of the baby’s organs, arteries and limbs, in addition to the position of the placenta, umbilical cord and the amount of amniotic fluid in the mother’s belly.

For anxious parents who want to know a little about the baby’s face, 3D or 4D ultrasound is a facilitating feature, as it is possible to see it in more detail.

For doctors, the exam allows the doctor to observe if the baby has cleft lip (when there is a cleft lip) or other more specific changes.

It is a safe exam for pregnant women and can be done between the 20th and the 24th week of pregnancy. Depending on the baby’s position in the tummy, parents who are curious about the baby’s sex may already find out through the examination.

The procedure can last between 20 to 40 minutes, being an important moment for the pregnant woman to clarify her doubts about the gestational development.

Read more: What is Maternity Leave, how it works, when to enter, new law

Ultrasound in physiotherapy

Ultrasound in physiotherapy is used to help treat inflammation (when the cause is already diagnosed and under treatment), to accelerate wound healing, repair fractured bones, muscle injuries, tendon injuries, ligaments, promote improved flow blood, muscle pain and spasms .

The number of sessions required for treatment depends on what is prescribed by the doctor and physiotherapist, and may vary according to the severity of the problem. However, it is not recommended to hold sessions for more than 20 consecutive days.

It can be done through two different techniques: continuous ultrasound and pulsatile ultrasound.

  • Pulsatile : more recommended for the treatment of acute injuries, as it emits waves with short pauses, without producing a thermal effect on the tissues. However, it also has the ability to reduce signs caused by inflammation or resulting from healing.
  • Continuous : different from pulsatile, it emits waves without interruption, causing a thermal effect, that is, they raise the temperature of the region. It acts by interfering with the metabolism and permeability of cells, which is also important for healing, reduction of swelling and improvement of injuries, in this case, more recommended for chronic injuries.

Aesthetic ultrasound

Although it is also an ultrasound, the way it is performed is different from what is done in medical ultrasound. In such cases, it is usually performed by a dermatologist or a specialist physiotherapist, who use a device other than the transducer.

With this device, circular movements are made over the treated region (legs, belly, arms and even face), which must also be prepared with the gel.

It should not be a painful treatment, what can happen is that the client feels a warmth in the place and a slight tingling. However, unlike the ultrasound done to diagnose diseases, the contraindications in these cases are greater.

The main indication is aimed at the treatment of cellulite, but it can also help in reducing localized fats.

This is because the ultrasound has a mechanical action, causing two different types of pressure under the skin alternately. Thus, it promotes a compression and expansion of fat cells, causing them to break down and be eliminated by the lymphatic system.

In addition, this type of ultrasound can also help to stimulate the production of collagen, improving the firmness of the skin in people who suffer from sagging neck or face, for example.

In this case, it is its thermal action, because, to combat sagging, the procedure causes the vibration of the molecules and the production of heat, causing the collagen to be stimulated.

To start seeing the results, 10 to 12 sessions are recommended, done biweekly, weekly or monthly. The results can be slower or faster, as it varies according to the organism of each person.

In addition to these beauty benefits, aesthetic ultrasound can also be used to improve circulation and to assist in the post-operative recovery of procedures such as liposuction.

It should not be done on people with pacemakers, with vascular problems ( thrombosis or atherosclerosis , for example), on skin with lesions or irritation, on regions of the body recently exposed to radiation and in pregnant and lactating women.

The price of the sessions can vary widely, depending on the clinic where it is held. The average can be between 80 to 100 reais per session.

For these aesthetic treatments, there are two types of ultrasound: focused and unfocused. Understand:

Unfocused ultrasound

Unfocused ultrasound is the most recommended for the treatment of cellulite, as it acts by altering the permeability of fat cells in the region, causing volume reduction, that is, reducing measurements. As cellulite is an inflammation of adipose tissue, it is by reducing this layer that cellulite is minimized.

Generally, it is done weekly or fortnightly, for at least 12 sessions. After these sessions, the client can choose to perform the aesthetic procedure monthly or every 3 months, as a form of maintenance.

It is worth emphasizing that this type of treatment, like other aesthetic procedures that aim to reduce cellulite and measures, must be done together with the practice of physical exercises and a balanced diet.

Read more: Detox juice: slimming, to lose belly, how to do, recipe

Focused ultrasound

The focused ultrasound, most used for the treatment of localized fats, directly affects the fat cell, as it causes the death or necrosis of the fat cell, but it can also help in the reduction of flaccidity, by stimulating the production of collagen.

This type of procedure should be done with longer breaks than the unfocused one. It is recommended that sessions be done at least one month apart. And, unlike the treatment for cellulite, the number of sessions can be reduced, between 1 to 3 sessions.

It is also not recommended that customers do maintenance, and it is more advisable to start a new treatment.

Read more: How to lose weight healthily: diet, exercise, medicine, menu

Special preparations

Before and after performing this procedure, some basic precautions are necessary:

  • It is important not to have any skin wounds in the region where the ultrasound will be used;
  • Have a very clean and dry skin. Therefore, it is important not to apply makeup or creams in the region;
  • Report to the professional who will perform the procedure of the medications you use, as some medications can alter blood clotting and, because of that, cause bruising.

Still on the session, in aesthetic procedures in which the deeper layers of the skin will be affected, it is possible that the client will feel a little pain or discomfort. In such cases, anesthesia can be applied.

After the session, very specific care is not necessary, the main recommendation being the practice of physical exercises to help eliminate localized fats, always according to the professional indication.

What can affect the results?

Some factors can interfere with the sharpness of the images obtained, which may impair the result. For example, in morphological ultrasonography, performed during pregnancy, it is important that there is a good amount of amniotic fluid in order for the captured images to be good.

The accumulation of gases, produced naturally by the organism, is also one of the factors that can affect the images obtained, as they may be between the organ to be analyzed and the transducer.

Scratchs

The risks present in the ultrasound are considered to be minimal and, in general, there are no contraindications, and it is always up to the professional to evaluate the need for accomplishment.

In general, aesthetic ultrasound is the one with the greatest limitations and attention. In these cases, there may be an absorption of wave energy by tissues and water present in the body, which raises the temperature of the region. Thus, patients may suffer from burns or blistering.

To avoid these risks, it is important to seek a competent and specialized professional in this type of procedure.

Price: how much does an ultrasound cost?

The price of an ultrasound examination may vary according to the purpose, and may be a different value for the examination in pregnancy, for diagnosis of diseases or for aesthetic treatment. It also depends on the region of the country and the clinic.

A morphological ultrasound, for example, can cost, on average, between 100 to 200 reais. For parents who wish to register the baby’s images in photos or video, there may also be an additional price to the exam fee.

For the diagnosis of diseases, the price may be a little more affordable. In some regions, it can vary from 20 to 180 reais, depending on the purpose of the diagnosis.

However, it can also be done through some health plans, which cover the exam, and through SUS, free of charge.

In aesthetic ultrasound, the values ​​are usually higher, even because it requires several sessions for a good result. The average ranges from 80 to 100 reais per session.

Contraindications

In general, ultrasound is a safe test. However, the doctor must evaluate all the clinical conditions of the patient before guiding him to an ultrasound, as in some special cases the examination cannot be performed.

In patients who are undergoing cancer treatment, who have severe circulatory problems, in areas of the body with acute inflammation, with open wounds, in patients with a pacemaker and in people with extreme sensitivity to the examination, ultrasound is not recommended.

In fractured areas or areas of the body such as eyes, ears and brain, greater care should also be taken. Normally, as recommended by the physician accompanying the patient, these contraindications are evaluated at the time of requesting the exam.

History of ultrasound within medicine

The first records of the use of ultrasound in medicine began during the 1940s. This was a technique seen as the remedy for many diseases, used in a general way and without scientific evidence.

It was neuropsychiatrist Karl Theodore Dussik, from the University of Vienna, who pioneered the use. He saw ultrasound as a way to identify brain tumors in patients, looking at the location and size of brain ventricles.

Other important names for the use of the procedure are those of John Reid and John Wild, the latter considered the father of ultrasonography within medicine. Wild was responsible for creating, in 1951, an instrument responsible for helping to detect tumors in the breasts.

Regarding the use of ultrasound for diagnosis, it is known that the doctor Douglas Howry and his wife were also one of the first to use the procedure. Still in the 1950s, the two began to use the technique on patients, in a much more complicated and distant process than is currently done.

In this context, the patient was immersed and immobile in a large bathtub with water. The result of the images, as well as the practicality of the exam, was not very rewarding, as they had low resolution.

However, Howry’s contribution was very important for the method currently used.

At the same time, the water bath gave way to the ultrasound gel.

A few years later, in 1966, John Reid and two other colleagues, Don Baker and Dennis Watkins, developed the use of pulsed doppler, a technique that also allows the analysis of blood flow and deeper structures of organs such as the heart.

In Brazil, this test started to be used in the 1970s, being especially used in obstetrics. Gradually, ultrasound has gained other spaces within medicine, currently used for various diagnoses.

Common questions

Can anyone take an ultrasound?

In general, yes . With the exception of the restrictions described in the Contraindications topic, ultrasound can be done on anyone, being a safe method.

Can I do ultrasound and endoscopy for the same day?

Yes , it is possible to do both exams on the same day. However, the ultrasound examination must be done before endoscopy.

Does ultrasound use radiation?

No , ultrasound is an examination done by emitting waves of sound waves. For this, it is not necessary to use ionizing radiation, as it is used in imaging exams such as x-rays , for example.

Which professional can perform an ultrasound?

It depends . Diagnostic ultrasound exams are performed by specialist doctors, who usually have a 3 to 4-year specialization in imaging diagnosis.

In aesthetic procedures, the indicated is that the sessions are made by dermatologists, physiotherapists or estheticians specialized in this type of procedure.

Does ultrasound cause pain?

No . Ultrasound does not cause pain. The doctor, during the exam, passes the transducer lightly pressed through the diagnosed region, which should not cause discomfort.

In transvaginal ultrasound, the type of procedure that is a little more invasive, can be uncomfortable if the woman is not calm during the exam, but, in general, it is not a painful process either.

How often can an ultrasound be performed?

When it comes to medical ultrasound, there is no definition regarding this periodicity. The examination is done according to the patient’s need, prescribed by the accompanying physician.

During pregnancy, to monitor the baby’s development, an average of 3 to 4 exams are performed.

In the case of aesthetic ultrasound it is a little different. The ideal is to respect the time intervals described in the topic Aesthetic ultrasound, always in accordance with the recommendations of the esthetician or dermatologist.

How many weeks can you see the baby on the ultrasound?

It is possible to see the baby by ultrasound only after the 5th week of pregnancy, but at that moment, the fetus contains an average of only 5 or 6 mm.

To know the sex of the baby, the wait must be longer. The most recommended is that the parents wait between the 11th and 13th weeks of gestation for this, which is also not a guarantee, since it also depends on the baby’s position inside the mother’s belly.

When can parents hear the baby’s heart on ultrasound?

Depending on the sensitivity of the device, it is possible to hear the baby’s heartbeat from the 5th week of gestation. With doppler ultrasound, in general, it is possible to hear from 12 weeks.

Sometimes, capturing the heartbeat is made difficult by the baby’s position. In such cases, it is important that pregnant women stay calm, as this is common to happen. The most favorable period to listen to the baby’s heart, therefore, happens around the 16th week of pregnancy.


Ultrasound, because it is a simple, non-invasive exam and allows the visualization of different structures of the organism, is often used for diagnosis and prevention of diseases in different medical specialties.

In this article we seek to clarify the main doubts about how the exam works and when it can (or should) be done. If you know someone who will take the exam, how about sharing this information? Thanks for reading!

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