When genetic counseling a pregnant or potentially pregnant woman, the physician should include her husband or other family members only at her request. Violating the patient’s privacy can have devastating results. Legal and social paternity do not necessarily imply biologic paternity. Although it would be proper to discuss these matters with the patient, this type of information should not be disclosed to others.

If the patient is a child, the situation is somewhat different. A father and mother who are married to each other have equal authority over their children. If the legal father does not question his biologic paternity, there is usually no problem. If a father asks whether he is the child’s biological father, a physician should be cautious. Both mutation and test variability can confound any genetic test of paternity. It is better to address the question of whether the child has a genetic disease than whether the disease came from the man asking the question.