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 1/14/2018
Updated by: John D. Jacobson, MD, Professor of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda Center for Fertility, Loma Linda, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.