Prenatal diagnosis of genetic disorders as an important adjunct to clinical medicine had already been recognized in the beginning of this century and amniocentesis has been used as a diagnostic tool since the early 1930's (1,2). During the past two decades transabdominal amniocentesis has gained widespread acceptance since it was found to be most useful in the management of Kh isoimmunization (3). Yet, this procedure has become available for diagnosis of a variety of genetic disorders only in the last 10 years (4). This paper will focus primarily on chromosomal disorders in relation to prenatal diagnosis,