The Difference Between 2D, 3D, and 4D Ultrasounds

If you're pregnant, you might be wondering what the difference between a 2D, a 3D, and a 4D ultrasound is. Most women will have at least one ultrasound done in pregnancy. As the newer imaging technologies become more widely available in ultrasound, you might hear various terms thrown around like 2D, 3D, and 4D ultrasounds.

There are differences in the types of ultrasounds done in pregnancy. All ultrasounds use sound waves to create a picture. The old standard is a 2D or two-dimensional image. In recent years, ​3D or three-dimensional images, and now four-dimensional images or 4D, have become popular. However, 3D and 4D ultrasounds are not considered standard prenatal tests and insurance may not cover the cost of these types of ultrasounds unless your doctor deems them medically necessary.

2D ultrasound gives you outlines and flat looking images, but it can be used to see the internal organs of the baby. This is helpful in diagnosing heart defects, issues with the kidneys, and other potential internal issues.

3D images are used to show you three-dimensional external images that may be helpful in diagnosing issues such as a cleft lip. What 4D ultrasound brings to the table is that as the image is continuously updated, it becomes a moving image, like watching a movie.

Each of these types of ultrasound has advantages and disadvantages. Many families prefer the 3D images because they look more like what they perceive a baby to look like in real life than the flatter 2D images. You should talk to your doctor or midwife about the type of ultrasound he or she uses and why. If your doctor or midwife doesn't offer you a 3D or 4D ultrasound and you'd like one, ask him or her about it.

Ultrasounds can be used to check a number of variables when you're pregnant, including:

• How your baby is developing
• Your baby's age
• Any problems in your uterus, ovaries, cervix, or the placenta
• How many babies you're carrying
• Any problems you and/or your baby may be having
• Your baby's heart rate
• Your baby's growth and position in your uterus
• The level of your amniotic fluid
• Signs of Down syndrome

The Food and Drug Administration (FDA) does not recommend that you get ultrasounds done for fun or bonding purposes, citing the use of ultrasound as a medical technology. This means that you should avoid places that offer ultrasounds that are not recommended by your doctor or midwife since the amount of time you and your baby are exposed to the ultrasound may not be limited and the ultrasound may not be performed properly. While ultrasound is considered safe, there is no research to indicate what prolonged exposure to ultrasound may do to a baby.