A three-dimensional ultrasound, which uses high-frequency sound waves and special imaging software to provide incredibly clear images of your baby, can be done at any point in pregnancy in addition to or instead of a traditional, two-dimensional ultrasound. While 3D ultrasounds are becoming more common, there's really no medical benefit to having one for most women, so you may or may not be offered one as part of your routine prenatal care. If you'd like to have one anyway, check with your insurance to see if they'll cover it.
The super-detailed images may be helpful if a potential problem is detected on a regular ultrasound. In these cases, being able to view the width, height, and depth of your baby and her internal organs can be helpful in making a diagnosis. If your doctor recommends a 3D ultrasound, your insurance will most likely cover it. However, it will not pay for ultrasounds given at shopping malls or other nonmedical venues (which many experts recommend you avoid anyway).
A 3D ultrasound is performed just like other ultrasounds. To conduct the exam, the doctor or technician will rub some gel on your belly and then move a transducer across the area. The transducer directs the sound waves toward your uterus and the baby inside it. Just as with traditional ultrasounds, a 3D ultrasound involves no radiation or x-rays, and is totally safe for both you and baby. The newest trend in the ultrasound world is the 4D ultrasound; the fourth dimension represents the addition of time. With in a 4D ultrasound, you get a 3D image of your baby with live action movement, so you can see what your baby's doing right at that very second -- smiling, smirking, thumb-sucking -- minus the short time delay of traditional ultrasounds.
Naturally the demand for 3D and 4D ultrasound has skyrocketed as more couples want to experience this intimate look at their babies. While this technology is becoming more widely available in doctors' offices, don't worry if you're not offered one. The traditional, two-dimensional ultrasound is still effective at screening for potential problems and making sure everything's fine in there. If you do decide to get a 3D or 4D ultrasound on your own, wait until you're at least 28 weeks along, since before that your baby really won't look all that cute in the pictures. And remember, the technicians at these places should not be relied on for any diagnosis or medical advice.