Accidental incest is sexual activity or marriage between persons who were unaware of a family relationship between them which would be considered incestuous.
For example, artificial insemination with an anonymous donated sperm may result in offspring being unaware of any biological relations, such as paternity or half siblings.
To reduce the likelihood of accidental incest, fertility clinics usually limit the number of times that a donor's sperm may be used.
Taiwan allows those conceived by artificial means to find out if they are related to a person they are considering marrying.
[4] Accidental incest may also arise in the following situations: Genetic sexual attraction is an unproven hypothesis, commonly considered pseudoscience, offered as an explanation for cases of sexual attraction and relations between adults who were not aware of their close blood relations.