The different types of prenatal ultrasound are transvaginal scans, standard ultrasound, advanced ultrasound, doppler ultrasound, 3-D ultrasound, 4-D ultrasound and fetal echocardiography, as reported by the American Pregnancy Association. These procedures help monitor fetus growth and detect abnormalities.
Transvaginal scans use probe transducers inside the vagina to generate sonogram images, and standard ultrasound produces 2-D images using a transducer over the abdomen, states the American Pregnancy Association. Advanced ultrasound works similarly to the standard ultrasound but targets a suspected problem. Doppler ultrasound measures slight changes in the frequency of the ultrasound waves, 3-D ultrasound generates 3-D images of the developing fetus, and 4-D ultrasound uses scanners to look at the face and movement of the baby. Fetal echocardiography assesses the baby’s heart anatomy and function.