Amniocentesis is done in an examination room, either with or without local anesthesia. It typically takes just a few minutes, during which you must lie very still. A technician locates your fetus with an ultrasound. Using the ultrasound for guidance, your doctor carefully inserts a long, but thin, hollow needle through your abdomen and into the amniotic sac. You should receive Rh immune globulin (RHIG) at the time of amniocentesis if you are an Rh-negative unsensitized patient.
Review Date 7/13/2021
Updated by: John D. Jacobson, MD, Department of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.