The Antenatal Genetic Testing Program at MCV began in 1973. The standard scheme for antenatal genetic testing involves counseling, the methods of carrier detection available, ultrasound, amniocentesis, and laboratory evaluation. Patients are referred because of a family or personal history of a genetic abnormality or because they have been evaluated in a carrier detection program like those for Tay-Sachs disease or Sickle Cell disease and are known carriers. After referral, patients are given genetic counseling by me and members of the Department of Human Genetics; if antenatal genetic testing is deemed appropriate, we obtain informed consent and proceed with an ultrasound study. The primary reason for doing an ultrasound study prior to amniocentesis is to detect twins. Twins are most likely to be in separate amniotic sacs and have different karyotypes; therefore, fluid must be obtained from each sac
