What Is A 4D Ultrasound Scan? Importance And How It Works

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Parents are often keen to see their babies inside the womb as they wait to hold them. A 4D ultrasound scan shows the live video of your baby, and you may be able to watch them smiling or yawning inside the womb.

Doctors recommend various scans and tests during pregnancy to ensure the wellbeing of both the mother and baby. Some of these tests are mandatory, while a few are optional. For example, the 4D ultrasound is an optional scan since a 3D ultrasound usually suffices to evaluate the baby. Unfortunately, it is illegal in some countries due to various reasons.

Read on to learn more about the 4D ultrasound scan, how it works, what you can expect, and whether your insurance covers it.

What Is A 4D Ultrasound Test?

A 4D ultrasound test is a way of reproducing a moving image of your baby inside your womb (1). The 4D ultrasound uses sound waves to create this moving image. In a 3D ultrasound, you can see a three-dimensional image of your baby. A 4D ultrasound takes this experience to the next level. It creates an effect that is similar to watching a live video. Using this technology, you can see what your baby is doing at that moment inside your womb. In fact, you can even see if your baby is yawning or smiling at that particular moment!

How Is The 4D Ultrasound Test Done?

The 4D ultrasound is done in a way that is very similar to other ultrasound procedures during pregnancy.

  • You will be asked to lie down on your back on the examination table.
  • A special gel will be applied on your belly by the medical technician.
4D Ultrasound scan

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  • This will help to carry the sound waves.
  • The technician will then hold a probe on your belly and move it in circular motions to get a good image.

How Does The 4D Ultrasound Work?

Here is how the 4D ultrasound helps create the image of your baby from inside the womb:

  • A device known as a transducer is moved along your abdomen.
  • This will send the sound waves via your abdomen and through your uterus.
  • These sound waves will bounce off your baby in the form of echoes.
  • The monitor will pick up these echo messages and translate them on to the screen.

The Results

Doctor will help you see your baby on the screen

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While the 4D ultrasound is in progress, your doctor will help you see your baby on the screen. This will enable you to know what your baby is doing right then.

The form of results that you will get from your 4D ultrasound may vary depending on your doctor and the medical procedure. While some results are given in the form of a picture of your baby, some doctors may hand out a proper 4D movie to you.

When Is A 4D Ultrasound Done?

Your doctor will be the best person to tell you when to get a 4D ultrasound. While some suggest getting it done between weeks 27 to 32, others may suggest getting it done between weeks 26 to 30.

It is important to note that from the 19 to 24 weeks of gestation, the gender of your baby can be determined through these scans (2). While this is legal in some parts of the world, it is considered illegal and punishable by law in other countries. Do have a word with your doctor to know when you can safely get this test done.

Important Points To Remember

4D Ultrasounds are usually safe

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It is natural that you may be super excited to see your baby for the first time while still inside your womb. However, do remember that this is not a good idea always.

  • According to most studies, 4D ultrasounds are safe and cause no threat to your baby. These 4D ultrasound scans can also help your doctor spot certain problems with your baby, particularly anomalies which may be picked up in 2D/3D but difficult to visualise otherwise, and discuss them with you before the delivery itself.
  • The concern is when you get a 4D ultrasound from companies who offer these results purely for the reason of showing you your baby’s face, and may not be necessarily qualified to look for abnormalities in your baby
  • While a 4D scan can sometimes give you a nice picture of your baby’s appearance, it is sometimes dependent on luck and your baby’s position at that moment to get a good angle/photo.
  • Ultimately, the 2D ultrasound scan remains the standard of care developed by sonographers around the world to look for developmental, structural and growth abnormalities in your baby.

Frequently Asked Questions

1. Can a 4D scan show the sex of the baby?

Yes, all ultrasound scans, including 4D scans, can show the sex of the baby (3).

2. How is 3D ultrasound different from 4D ultrasound?

A 3D ultrasound allows doctors to visualize some facial features and body parts of the fetus more clearly. A 4D ultrasound, on the other hand, is a 3D ultrasound in motion. It shows embryonic movements with clarity (4).

3. Are 4D ultrasounds a standard practice?

No, 4D ultrasound has been recently introduced and is not a standard practice. Doctors mostly use it to complement 2D and 3D observations (4) (5).

4D ultrasounds help you view a moving three-dimensional image of your baby from inside your womb. The procedure is similar to that of a normal ultrasound, but this procedure uses sound waves instead of ultrasonic waves. It is advisable to get this ultrasound done either by the end of the second trimester or the beginning of the third trimester to capture a true image of the baby. Remember to consult your doctor before going through this procedure since it is optional. It is done so that couples can have a better look at their baby.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
  1. New Dimensions in Prenatal Ultrasound: 3D and 4D.
  2. Gestational Age.
  3. 20-Week Ultrasound (Anatomy Scan).
  4. Ultrasound.
  5. Dr. Florentina-Daniela Lebit and Professor Dr. Radu Vladareanu; (2011); The Role of 4D Ultrasound in the Assessment of Fetal Behaviour.
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Sadiya Qamar

Sadiya is a writer and editor with a passion for writing about parenthood and children. Her focus areas are health, wellness, and beauty. For MomJunction, she writes on kids’ health and nutrition.  Sadiya believes in doing in-depth research and providing accurate information to help parents with concerns on their children’s growth and development.

Dr. Ng Kai Lyn

(MMed (O&G), MRCOG)
Dr. Ng Kai Lyn is a Singapore-based obstetrician and gynecologist, specializing in urogynecology, minimally invasive surgery, and clinical interest in fertility. She has vast experience managing and treating benign gynecological conditions, including uterine fibroids, ovarian cysts, endometrial polyps, and endometriosis. She is also fellowship trained in urogynecology. She manages pelvic organ prolapse, pelvic floor reconstructive surgery, overactive bladder, urinary incontinence,...
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