Your Baby

Many women have an opportunity to see their unborn baby during an ultrasound examination during pregnancy. Ultrasound is one of the most common tests in pregnancy. It uses high-frequency sound waves to create an image of the fetus' body and organs and the surrounding tissues. Although there are no set guidelines for having an ultrasound, many women have an ultrasound during the second trimester to:

• Confirm pregnancy dates.
• Determine the number of fetuses and examine the placental structures.
• Assist in prenatal tests, such as an amniocentesis.
• Examine the fetal anatomy for presence of abnormalities.
• Check the amount of amniotic fluid.
• Examine blood flow patterns.
• Observe fetal behavior and activity.
• Examine the placenta.
• Measure the length of the cervix.
• Monitor fetal growth.

If your doctor recommends an ultrasound scan, it may be done in the obstetrician's office, or by a specialist, such as a radiologist or maternal-fetal medicine doctor.

There are two types of ultrasound:

• Abdominal ultrasound. During an abdominal ultrasound, gel is applied to the abdomen and the ultrasound transducer glides over the gel on the abdomen to create the image. You may need to have a full bladder to help move the uterus into better view.
• Transvaginal ultrasound. In a transvaginal ultrasound, a smaller ultrasound transducer is inserted into the vagina and rests against the back of the vagina to create an image. A transvaginal ultrasound produces a sharper image and is often used in early pregnancy.

Although you may have some discomfort from the pressure of the ultrasound transducer or from having a full bladder, there is no known evidence of any type of danger to you or your unborn baby with ultrasound.

Ultrasound images may be captured in still photographs or on video to document findings. There are several types of ultrasound imaging techniques. The most common is two dimensional, or 2D. This gives a flat picture of one aspect of the image.

If more information is needed, a 3D ultrasound examination can be performed. This technique, which provides a three-dimensional picture, requires a special machine and special training. But the 3D image allows the health care provider to see width, height, and depth of images, which can be helpful in diagnosis. The 3D images can also be captured and saved for later review.

The latest technology is 4D ultrasound, which allows the health care provider to visualize your unborn baby moving in real-time. With 4D imaging, a three-dimensional image is continuously updated, providing a "live action" view. These images often have a golden color, which helps show shadows and highlights.

Ultrasound gives you a unique opportunity to see your first baby pictures, but more important, it provides your health care provider with technical information about your pregnancy. Ultrasound is a technique that is constantly being improved and refined. Ultrasound can provide valuable information to help your health care provider as he or she cares for you and your unborn baby.