Ultrasounds are safe, noninvasive imaging tests that use high-intensity sound waves to produce images of soft tissues inside the body. The images are called sonograms.
For pregnant women, prenatal ultrasounds are used to confirm that you're pregnant, check to see if there is more than one baby, determine how long you've been pregnant, check the growth and heart rate of the baby, and check for any congenital conditions. Ultrasounds can also detect the sex of the baby.
Ultrasounds are also used to view other parts of the body to help in diagnosing the cause of unexplained pain or swelling, for example, or to examine your reproductive organs. Diagnostic ultrasounds are performed by placing a probe or transducer on your skin like the prenatal ultrasound, or in your vagina during a pelvic ultrasound.