Accidental incest


Accidental incest is sexual activity or marriage between persons who were unaware of a family relationship between them which would be considered incestuous.
The laws of many jurisdictions void incestuous marriages, even if entered into without awareness of the kinship. If an incestuous relationship is suspected, DNA testing may be used. Some jurisdictions permit offspring of IVF donations access to donation records or to adoption records.

Causes

People may be unaware of a kinship relationship between them in a number of circumstances. 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. Some countries have laws limiting the number of children a donor can father, while others limit sperm donations based on family numbers to enable one family to have true siblings.
Taiwan allows those conceived by artificial means to find out if they are related to a person they are considering marrying.
Accidental incest may also arise in the following situations: