When is 4D ultrasound performed in pregnancy? Its advantages

By (embryologist) and (embryologist).
Last Update: 09/02/2024

After knowing 2D ultrasound (two-dimensional) and 3D ultrasound (three-dimensional), we now have 4D ultrasound or "three-dimensional ultrasound in real time".

This diagnostic imaging test makes it possible to observe the morphology of the baby, but also its movement. Moms and dads-to-be will be able to see what the baby is doing at that moment.

4D ultrasound has advantages and disadvantages like other tests. For example, 4D ultrasound offers high quality images and is less expensive than 5D ultrasound, although it has limited visibility.

What is 4D ultrasound?

4D ultrasound can be understood as a three-dimensional ultrasound that moves, i.e., that changes over time. Therefore, 4D ultrasound is like a video.

4D ultrasound combines the characteristics of its predecessors with the addition of a fourth dimension, the movement of the fetus in real time. This diagnostic imaging test helps to have a more realistic perception of the behavior of the fetus and its motor and physiological activity inside the uterus.

Thanks to 4D ultrasound it is possible for future parents to visualize gestures such as yawns, smiles, etc. of their baby. In addition, the 4D ultrasound can also reflect if there is any malformation of the face in the position of the feet. In this ultrasound the gynecologist will also check the amount of amniotic fluid, the umbilical cord, the placenta, the cervix and the walls of the uterus.

However, it should be noted that, although this ultrasound can be used to observe the fetus with a high quality image, it should not be taken as a true prenatal diagnosis. This is a complementary technique to try to obtain more information.

How and when is it performed?

4D ultrasound, like 2D and 3D ultrasound, is based on ultrasound emission and is performed with the same ultrasound scanner used for 3D ultrasound, incorporating a specific probe. It is not a harmful test for either the mother or the fetus.

One of the requirements for a good 4D ultrasound is that there must be a sufficient amount of amniotic fluid between the surface to be studied and the ultrasound probe. It is for this reason that the right time to perform this ultrasound is between 25 and 32 weeks of gestation.

It is not recommended to do it later, since in later weeks of pregnancy the fetal volume increases and the amount of amniotic fluid decreases, making it difficult to obtain a good three-dimensional image of the fetus.

Advantages of 4D ultrasound

One of the great benefits of 4D ultrasound is the evaluation of the heart (cardiovascular system) and the detection of congenital heart disease with greater safety and accuracy. Thanks to real-time observation, it is possible to explore the fetal heart in slow motion and perform a more comprehensive study in real time.

Another advantage of 4D ultrasound is that all the images are recorded in the software and can be analyzed in detail at any time to make a more accurate diagnosis.

On an emotional level, 4D ultrasound provides value to future mothers and fathers. Seeing the baby moving inside the uterus gives them greater peace of mind than seeing the traditional static black-and-white image obtained with a 2D ultrasound.

Through 4D ultrasound, parents can see their baby's facial gestures in real time, for example if the fetus smiles, blinks or yawns. Afterwards, the gynecologist will give you a CD copy of this unique moment to keep as a souvenir.

Are there any drawbacks to 4D ultrasound?

4D ultrasound, like other types of ultrasound, is not an invasive test and does not cause harm to the mother or the baby. Nevertheless, 4D ultrasound may have some disadvantages.

The first is that in the third trimester of pregnancy the three-dimensional image of the fetus is not as clear due to the volume it occupies inside the uterus and the decrease of amniotic fluid inside the placenta.

In addition, it is not always possible to obtain the image in 4D. In 10% of the cases it is not possible to obtain a good image of the baby due to poor fetal position, placenta, umbilical cord, insufficient amount of amniotic fluid or abdominal fat (obesity) of the patient.

When a woman goes for a 4D ultrasound, it is important to keep in mind that the scanning time cannot be prolonged beyond 35 minutes, since uterine contractions may be generated due to the manipulation of the uterus.

Finally, another disadvantage of 4D ultrasound is the price. Depending on the center where it is performed, 4D ultrasound can cost up to twice as much as a 2D ultrasound.

FAQs from users

When is it advisable to perform a 4D ultrasound?

By Marta Barranquero Gómez B.Sc., M.Sc. (embryologist).

Ideally, the 4D ultrasound should be performed between the 24th and 32nd week of pregnancy. If only the baby's movement is to be observed, then the indicated gestational weeks for 4D ultrasound would be between 16 and 22 weeks.

What are the differences between 3D, 4D and 5D ultrasound?

By Marta Barranquero Gómez B.Sc., M.Sc. (embryologist).

3D ultrasound adds depth to the image, providing a more realistic image. On the other hand, 4D ultrasound also includes the vision of the baby's movement.

The 5D ultrasound is the most advanced and, in addition to contemplating depth and movement, it also improves the resolution through the play of light and shadows. Therefore, 5D ultrasound is the test that offers the best and most realistic images of the baby.

What does a 4D ultrasound scan feel like?

By Marta Barranquero Gómez B.Sc., M.Sc. (embryologist).

The 4D ultrasound is a painless and non-invasive test. Therefore, it will only be a special moment where you will be able to see the baby and its movement in real time.

Suggested for you

If you want to learn more about other tests during pregnancy, we recommend you to visit the following link: Prenatal pregnancy control: tests, analyses and ultrasound scans.

If you are interested in knowing the difference with respect to 3D ultrasound, then we invite you to read this article: 3D ultrasound in pregnancy: advantages and disadvantages.

We make a great effort to provide you with the highest quality information.

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References

Asim Kurjak. 3D/4D Sonography. J Perinat Med. 2017 Aug 28;45(6):639-641. doi: 10.1515/jpm-2016-0431 (View)

Belén Moliner, Joaquin Llacer, Francisco Sellers, Juan Carlos Castillo, Ana Fuentes, Andrea Bernabeu, Rafael Bernabeu. 4D ultrasound as a method to assess uterine peristalsis. Fertil Steril. 2021 Jul;116(1):272-274. doi: 10.1016/j.fertnstert.2021.02.017. Epub 2021 Mar 20 (View)

Eileen Hwuang, Marta Vidorreta, Nadav Schwartz, Brianna F Moon, Kirpal Kochar, Matthew Dylan Tisdall, John A Detre, Walter R T Witschey. Assessment of uterine artery geometry and hemodynamics in human pregnancy with 4d flow mri and its correlation with doppler ultrasound (View)

S Yagel, S M Cohen, I Shapiro, D V Valsky. 3D and 4D ultrasound in fetal cardiac scanning: a new look at the fetal heart. Ultrasound Obstet Gynecol. 2007 Jan;29(1):81-95. doi: 10.1002/uog.3912 (View)

FAQs from users: 'When is it advisable to perform a 4D ultrasound?', 'What are the differences between 3D, 4D and 5D ultrasound?' and 'What does a 4D ultrasound scan feel like?'.

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Authors and contributors

 Marta Barranquero Gómez
Marta Barranquero Gómez
B.Sc., M.Sc.
Embryologist
Graduated in Biochemistry and Biomedical Sciences by the University of Valencia (UV) and specialized in Assisted Reproduction by the University of Alcalá de Henares (UAH) in collaboration with Ginefiv and in Clinical Genetics by the University of Alcalá de Henares (UAH). More information about Marta Barranquero Gómez
License: 3316-CV
 Teresa Rubio Asensio
Teresa Rubio Asensio
BSc, MSc
Embryologist
Master's Degree in Medicine and Reproductive Genetics from the Miguel Hernández University of Elche (UHM). Teacher of different Clinical Embryology courses at the UHM. Member and writer of scientific contents at ASEBIR and ASPROIN. Embryologist specializing in Assisted Procreation at UR Virgen de la Vega. More information about Teresa Rubio Asensio

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