Every woman, when she discovers she is pregnant, gets anxious to have an ultrasound and see how her baby’s growth and development is progressing. If she can already see detailed features of her baby’s body as in a 3D or 4D ultrasound, even better. What is an ultrasound? Ultrasound, also known as sonography or ultrasonography, is a diagnostic imaging exam used to visualize, in real time, any organ or tissue in the body with rich detail.

Indications for ultrasound

  • To diagnose pregnancy or assess the baby’s development.
  • To diagnose diseases of the uterus, fallopian tubes, ovaries;
  • To visualize the structures of muscles, joints, tendons; or
  • To visualize any other structure in the human body.

It is important to mention that all ultrasound exams must be done in specialized laboratories and under medical recommendation. Only a trained professional is able to analyze and give the correct diagnosis and treatment for the different situations.

What are 3D and 4D Ultrasounds

The 3D ultrasound exam (three dimensions) is an evolution of the 2D ultrasound method, which transforms traditional images into three-dimensional images, allowing the mother to see a more realistic copy of her baby. These images are like photographs of the baby with similar quality.

When to Have a 3D Ultrasound?

Both 3D and 4D ultrasounds can be done at any point during pregnancy. However, it is important to note that depending on gestational age, the image shown can be very different. For example, images taken early in pregnancy will show the baby’s body in a single, full form, but cannot capture small details because the baby is still very tiny. Near the 20th week of pregnancy it is already possible to get some images of the face and features; however, these still will not be very pretty since the baby is not yet chubby at this stage. The best images of the baby’s face are usually obtained between the 26th and 29th weeks of pregnancy, as at this time the baby already has a good amount of fat under the skin and there is still plenty of amniotic fluid (which is very important for clear images). After the 30th week it is still possible to get good images, but it becomes much harder because the space inside the uterus is limited and the face will be hidden most of the time. That’s why the recommendation is to plan the exam between the 26th and29th week of pregnancy.

What is 4D ultrasound?

Using the same method as the 3D ultrasound, 4D ultrasounds generate three-dimensional images but add time as the fourth dimension. It is possible to see perfection and realism, in small details of the face, so parents can even guess who the baby might resemble. All other body parts can be clearly seen, as well as movements. These are 3D images with real-time movement. The way the baby moves during the exam allows the doctor to observe the structures shaping the baby’s development, for example, the heart, spine, limb movements, and more.

Difference Between 3D and 4D Ultrasound and Conventional Ultrasound

The main difference with this technique compared to regular ultrasound is the way the machine processes and displays the captured images because the traditional method only allows you to see the baby’s bones and internal organs. But in 3D and 4D ultrasounds, it is possible to see the layer of skin covering the baby.

What’s the Difference Between 3D and 4D Ultrasound?

As mentioned above, the way the images are rendered to the specialist makes study easier, but the main difference is that 3D produces static images, though with better quality, while 4D ultrasound allows you to watch images in motion. Because these images are captured quickly and continuously, their quality ends up a little lower.

Can the image be unclear?

Some factors can make image capture unclear. They are:

  • Baby’s position – Babies usually lean against the uterine wall, which makes capturing images difficult. Another reason for a poor image is if the baby is facing the mother’s back, making it impossible to get a picture of their face.
  • Color and structure of amniotic fluid – We know that when the baby’s digestive system is developed, they use the amniotic fluid for practice, swallowing and urinating. At a certain point this liquid can hold particles that alter its color. Ideally, to produce clear images, the fluid should be dark so that it contrasts with the baby’s skin, creating the conditions required for image reconstruction.
  • Amount of amniotic fluid – When the volume of amniotic fluid drops, it may not be possible to capture a good image.

Cost of 3D and 4D Ultrasound

Usually, both methods have similar prices, ranging from R$ 200.00 to R$ 600.00, but believe it, there are clinics that charge up to R$ 1,000.00. Because it is expensive, most insurance plans do not cover this type of technique.

Where to Get It Done

There are specialized clinics for these exams and also some hospitals in large cities. With modern equipment, it is no longer difficult to find a place.

Can I record the 3D and 4D ultrasound?

Yes. Usually clinics offer the option to record a DVD with the images collected during the 3D and 4D ultrasound. To do this, just bring a DVD or, in many clinics, recording is already included in the price. In favorable conditions, it can be fast and easy to get clear images. In unfavorable situations, the ideal is for the exam not to last more than 20 minutes. With movement in the abdomen, the baby acts on instinct, covering the face with their hands or turning toward the mother’s spine.

Information that appears on ultrasounds

Basically, at the top of the screen are personal details, date and time, information on the location where the exam is being performed, and the specialist’s name. Technical information includes the position of the machine, color variations that indicate solid tissue like bones (usually in white), and tissues considered liquid structures such as the uterus, which remain darker. The baby’s measurements are also displayed on the screen. Below are the initials and what they mean: CRL – This stands for crown-rump length. This measurement, done at the first ultrasound, helps determine the pregnancy duration. NT – The nuchal translucency measurement, which analyzes the size of the baby’s neck area at the start of pregnancy and can detect chromosomal diseases such as Down syndrome. FL – This is the length of the femur, the largest bone in the body, which helps to track the baby’s growth. AC – Stands for abdominal circumference. This measurement is extremely important at the end of pregnancy, as it helps estimate the baby’s weight. With all this information, it is much easier to choose the type of exam you want to do! Good luck!! Also see: Ultrasound – Questions and Answers Photos: TF Personal Collection