Redefining parenthood.

Michael Douglas' ex-wife, Diandra, moves in with Zack Hamton Bacon III, a New York hedge-fund executive. When they try to have kids by IVF and failed, they tried a surrogate, and that failed, as well. (It's unclear whether the IVF attempts and the surrogacy attempt are the result of an infertility problem with one of the prospective parents or is simply a matter of preference. Both Diandra and Zack are parents of children from their previous marriages.) They engage the services of another surrogate in Southern California, where Diandra lives when she's not in NYC. The surrogate gets pregnant through IVF with a donated oocyte. In fact, she's carrying twins, who are born about 3 months early.

Diandra and Zack are now splitting. She's filed for custody in California. He's filed in Manhattan for an order that would force Diandra to bring the children to New York. If the case stays in California, is Diandra -- who is neither the genetic mother nor the gestational mother -- the mother of the boys and therefore entitled to assert parental rights? Students in this summer's Bioethics and Law course know the answer, courtesy of Johnson v. Calvert and Buzzanca v. Buzzanca. For everyone else, here's the end of today's article in the N.Y. Times:

If the case stays in California, the fact that Ms. Douglas is not the biological or genetic mother of the twins is unlikely to make a difference, because case law here emphasizes intent when deciding who is a legal parent, said Leslie Ellen Shear, an Encino lawyer who has been involved in many surrogacy cases.

Surrogacy, unmarried parents, relocation issues, allegations of domestic violence are all becoming common in family court cases, she said. Which doesn't mean that they are easy for courts to decide.

But she noted, "We invented courts to deal with all the difficult problems for which there is no social consensus."

Of course, all of this presumes that California law would apply. I don't know whether New York's law would be any different, but if it is, then this will shape up into an epic choice-of-law battle before it becomes an epic family-law or bioethics battle.

If California is still Diandra's domicile, and the contract was entered into and performed there, and the children are there, presumably California law would apply. Even if the case were litigated in New York, which seems to be what Zack is angling toward, New York courts might well conclude that California law should apply. Or not . . . .