Using the sperm of a relative of an infertile man may seem to be a good solution; the child will be genetically related to the legal father and will look like a member of the family. There are, however, some serious drawbacks. If a genetic problem is involved in the infertility, then the closer the relationship is to the father, the greater is the chance that the donor is also affected. Even if state law severs parental rights for a sperm donor, it will not sever the other relationship. If a brother is used as a donor, he is still the child’s legal uncle. If the extended family is aware of the arrangement, they may treat the child as though the biologic father were the legal or social father. In case of divorce of the legal parents and/or infertility in the marriage of the donor, there may be a battle for custody of the child. An uncle has the right to go to court and challenge the fitness of a parent. If the uncle is also the biologic father of the child, this relationship may strengthen his case before the judge whatever the law on sperm donation may be.

The use of a relative of the mother carries the same legal risks plus the medical risks of consanguinity. In most cases, the risks of recessive genetic disease are not high, but using a maternal relative as donor carries a higher risk than using an unrelated donor. In addition, if custody questions do arise, the mother may face undue prejudice because of the cultural abhorrence of incest. Although artificial insemination with her brother’s sperm is not the same as marrying her brother, the distinction may be irrelevant to a judge or a jury in a custody case.