Among states where there are laws, there is hardly consistency. Not all states recognize the intended parents as the legal parents from birth. Prospective parents should make certain they understand existing state laws, as well as check with an experienced attorney, estate planner and/or fertility counselor to ensure that all required paperwork and procedures are complete. Some states, meanwhile, might require a parent unrelated by genes to petition the court for recognition before the baby is born. Still others require the parent who is not related to go through a curtailed—or even complete—adoption proceeding after the baby is born.

Laws also change over time as societal perceptions evolve. Dinsmore Adams, an estate planning attorney with Curtis, Mallet-Prevost, Colt & Mosle in New York, points out that as late as the 1950s, unless a person specifically named an adopted family member as the beneficiary of a will or trust, that person would often be cut out. “It was thought that if there was a question, the money should follow the blood,” he says. “That eventually changed.”

Indeed, state law prevails when a person dies without a will or trusts in place. However, even if a parent puts wishes in writing, problems can arise if the documents do not properly address a situation of assisted reproduction. This situation often requires a local judge to weigh in. As Robert Browning, an estate planning attorney with WealthPlan in San Jose, points out, even if a parent and the state recognize a child as entirely the parent’s, that doesn’t mean the child is an heir. Families can seize on language that does not specifically include a child born by alternative means to argue that a distant relative, or even a grandparent or parent, did not intend for the child to be an heir.

Even if a parent and the state recognize a child as entirely the parent’s, that doesn’t mean the child is an heir.

A New York court case decided earlier this year illustrates the unpredictable nature of estate planning as it relates to ART. In 1959, a New York lawyer created a trust that would eventually benefit his grandchildren, however he specified that adopted children “shall not be recognized.” Decades later, one of his daughters and her husband had twins using the husband’s sperm, a donor egg and a surrogate mother in California. The trustees then went to court to determine whether the trust should benefit the twins or if they should be excluded as adopted children.

The judge relied on the fact that California—the home of the surrogate—did not consider the children to be adopted. That state has separate processes for establishing parenthood via adoption and surrogacy. In this particular case, the original trust funder had specified that spouses could receive money from the trust, which indicated to the judge that the man was open to nonblood relations benefiting from it. Because there was nothing in the documents to signal that the man would have wanted to exclude children born through assisted reproduction—which was still science fiction in 1959—the court declared the twins to be their mother’s—and therefore their grandfather’s—descendants who could receive money from the trust.

Adams, one of the attorneys who represented the trustees, says he believes the case has modest precedent value, because it is hard to imagine a similar collection of facts cropping up again. But the case shows how difficult it is to predict how fertility issues will arise in a family and what unexpected questions they might raise.