Counseling before fetal blood sampling via cordocentesis is more difficult than that done before amniocentesis because 1) a fetal anomaly has been detected or is very likely, 2) the cordocentesis procedure may have a higher risk than does amniocentesis, and 3) the gestational age is frequently advanced before referral. These factors result in counseling and decision dilemmas that include that 1) the advanced gestational age may preclude the option of termination, 2) fetal prognosis may be poor despite normal cytogenetic results, and 3) the benefit of a diagnosis to provide indications for various delivery options must be weighed against the psychological burden of documenting a chromosome abnormality far in advance of delivery. Thus, counseling before cordocentesis requires engaging the couple in decision making regarding potential management of the pregnancy as a prerequisite to choosing or declining the procedure.