There appears to be a consensus among medical professionals that husbands should not be told when they are not their wife’s child’s father. In a new paper in the journal Bioethics, Erica Lucast says
Counselors … tend to be cautious and prefer to deceive male clients when possible in order to protect their partners [while] … patients … tend to favor disclosure when it is done sensitively and with ample warning to the woman.
She cites a Journal of Genetic Counseling survey, published in 1990, of 677 geneticists in 18 countries, responding to this scenario:
You are evaluating a child with an autosomal recessive disorder for which carrier testing is possible and accurate. In the process of testing relatives for genetic counseling, you discover that the mother and half siblings are carrier, whereas the husband is not. The husband believes that he is the child’s biological father.
The results depended very little on the country:
96% of respondents believed that protection of the mother’s confidentiality overrode disclosure of true paternity. Of these, 81% … said that they would tell the mother in private, without the husband present, and let her decide what to tell him; 13% … would tell the couple that they are both genetically responsible, and the remaining 2% would ascribe the child’s disorder to a new mutation, a one-in-a-million-occurrence. As their reasons for such answers, 58% cited preserving the family unit, 30 % cited the mother’s right to decide, and 13% cited the mother’s right to privacy.
Lucast goes even further, arguing that medical geneticists should not even offer couples an informed consent option to decide up front whether they would want to know if genetic tests reveal that the husband is not the father. Her reason is that doing so could inform husbands that genetic testing can reveal paternity.
It is much more likely that bringing up the possibility prior to testing will put the woman in the very position we are trying to protect her from. … If, as I have suggested, the counselor plans to attempt to keep paternity but not personal genetic information from the man, it is probably better not the discuss the issue ahead of time.
I wonder how often medical professionals, given a choice, tell a wife that she caught a sexually transmitted disease from her philandering husband.
Addendum: Tom Crispin points us to "Judge bans husband from naming adulterer," and Annrandgirl points us to "men [without custody] banned from testing a child’s DNA" and "man [needs] consent of his accuser," all from the United Kingdom.