No doubt you’re anxious to see your growing baby in your belly — after all, nine months is a long time to wait to catch a glimpse of those tiny fingers and toes. And since 3D and 4D ultrasound exams allow you to see your unborn baby in even more depth and detail than a standard 2D ultrasound, you may be really eager to have a look.
But before you do, it’s important to understand when 3D sonograms and 4D sonograms should be used during pregnancy to ensure you’re doing everything possible to keep you and your baby safe and healthy.
What’s the difference between 2D, Doppler, 3D and 4D ultrasounds?
During your pregnancy, you may receive a combination of the following ultrasounds:
2D ultrasounds: If you’ve visited the doctor, you’ve probably already experienced a 2D (two-dimensional) ultrasound and know it can be an exciting and magical moment. For this exam, a wand (transducer) is placed on your belly or into your vagina to send sound waves through your body. The waves bounce off internal organs and fluids, and a computer converts these echoes into a two-dimensional image (or a cross-sectional view) of the fetus on a screen.
Doppler: With Doppler fetal ultrasound, your doctor uses a hand-held ultrasound device to amplify the sound of the fetal heartbeat with the help of a special jelly on your belly.
3D ultrasounds: For 3D ultrasounds, multiple two-dimensional images are taken at various angles and then pieced together to form a three-dimensional rendering. For instance, instead of just seeing a profile view of your cutie’s face, in a 3D sonogram you can see the whole surface (it looks more like a regular photo).
4D ultrasounds: A 4D ultrasound is similar to a 3D ultrasound, but the image shows movement like a video would. So in a 4D sonogram, you'd see your baby doing things in real time (like opening and closing his eyes and sucking his thumb).
Why 3D and 4D sonograms are performed during pregnancy
Medical practitioners use 2D and Doppler ultrasounds in uncomplicated pregnancies to examine the fetus, assess amniotic fluid and look for birth defects, among other reasons.
Ultrasounds in 3D and 4D are performed only to closely examine suspected fetal anomalies, such as cleft lip and spinal cord issues, or to monitor something specific. In other words, 3D sonograms and 4D ultrasounds are usually not part of routine prenatal exams.