ABSTRACT
Although cytogenetic abnormalities contribute significantly to human mor bidity and mortality as causes of neonatal death, mental retardation, con genital abnormalities, reproductive problems, and cancer, their major con centration is found among those human conceptions which do not survive to term. Embryonic or fetal loss due to developmental abnormality reduces the incidence of cytogenetically detectable genetic abnormalities from as many as 30% of all conceptions to approximately 0 .5% of livebirths. In this chapter we shall examine methods for studying human gametes and products of conception, the incidence and types of cytogenetic anomalies detected, and their pathologic correlates .
