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A: Your baby's heartbeat is one of the first things your doctor will look for on an ultrasound, a test that uses sound waves to give off visual images of your baby and placenta as well as your uterus and other pelvic organs.
Throughout a woman's pregnancy, her doctor will typically begin a prenatal exam with listening to the baby's heartbeat. Although a Doppler instrument is most frequently used, a fetoscope, a type of stethoscope, can be used after 20 weeks to hear a baby's heartbeat. A baby's heartbeat is checked often to monitor how the baby is developing and coping with the stress of the pregnancy and labor.