The California Supreme Court recently heard arguments in three cases involving lesbian couples that split up after becoming mothers. The problem is that the laws designed to fix rights and responsibilities of parents after a divorce were crafted with straight couples in mind, with the result that it is not clear what happens when only one of the parents is biologically related to the child (as is the case when one partner is artificially inseminated, for example). This problem is complicated by the fact that each of these divorces were on extremely unfriendly terms. As a result, the biological mother is put in a position in which her best legal argument for keeping custody of the child may very well be that lesbian couples should not be treated on equal legal footing with straight couples.

The laws need to be fixed in order to recognize these all too common problems. Families that are tied together by something other than pure biology are becoming more and more common, and absent the availability of institutions like marriage to create binding legal ties between family members, these situations are going to continue to be even more difficult to resolve than they already are. In many cases, the non-related mother will adopt the child in order to achieve a legal status on par with that of the biological mother. But even that option is not always available, particularly in states that do not allow gay individuals to adopt, or that do not allow unmarried partners to adopt a child if the biological parent does not relinquish her own parental rights.

Personally, I think this kind of situation makes it crystal clear that same-sex couples need to have access to an institution like civil marriage, civil unions, domestic partnership, or whatever one wants to call a state-recognized bond between two people. It also is necessary to clarify parentage in cases of artificial insemination or surrogacy in cases in which the couple involved, whether straight or gay, has chosen not to get married. The fact that one partner contributes no biological material should not be the sole decisive factor in determining custody, child support rights, or the myriad other legal issues arising out of the decision to start a family.