As you lie on an exam table, a sonographer coats your belly with a slick -- and possibly cold -- gel. Next, he moves a transducer, a hand-held device shaped like a microphone, over your belly. You can see the resulting images on a nearby computer screen.
Review Date 1/30/2020
Updated by: LaQuita Martinez, MD, Department of Obstetrics and Gynecology, Emory Johns Creek Hospital, Alpharetta, GA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.