3D (three dimensional) ultrasound is a miracle of modern technology and can allow you to view an image of your baby while still inside. The images you see can be fun and reassuring. Sometimes called “Keepsake” ultrasound, the best time to do this is between 28-34 weeks. This is because during this time frame the fetus begins to look more like a newborn and there is enough amniotic fluid for the sound waves to travel through. The ultrasound machine sends out sound waves that reflect off of tissues of varying density which the machine then translates into a picture. The idea is similar in theory to the sonar of a submarine. You will receive multiple pictures and these can be transferred to a CD-ROM or DVD disk and uploaded onto your computer to post to family and friends if so desired. Most of the medical literature documents the safety of prenatal ultrasound and we at Birthing Instincts are confident that when used appropriately for proper indications your baby will not be affected by the scan.
4D ultrasound scanning is just a static 3D picture but in real time. This means that you can sometimes see your baby yawn or smile or blink while moving around. While this technology is amazing is does not really add much to the routine screening of fetuses. It is not a necessary part of your anatomic ultrasound at 20 weeks. However, I believe that the reassurance of seeing your baby and having a picture will contribute to the confidence and serenity that enhances the home birth experience.