The debate over extending employers' health plans to include unmarried couples has become complicated, says the National Journal, "by the drive for gay rights and by the growing political pressures to bolster the traditional family."

In some cases, advocates for both homosexuals and the traditional family have opposed local governments granting family health benefits to the nonemployee in unmarried heterosexual couples -- so-called domestic partners or cohabitants.

• At least 34 municipalities -- including New York and Los Angeles -- now offer health care benefits to domestic partners, whatever their sex.

• But seven other cities -- including Baltimore, Chicago, Denver, New Orleans and Philadelphia -- only extend benefits to same-sex couples.

• Santa Barbara and Oakland, Calif., initially planned to cover only same-sex couples, but adopted broader plans last year after attorneys warned they would be liable to sex discrimination suits by heterosexuals.

The Human Rights Campaign says laws extending benefits to same-sex couples only are appropriate, because homosexuals can't marry. And Massachusetts' acting Governor Paul Cellucci vetoed a bill to allow Boston to extend benefits to city employees' domestic partners because it "undermines strong marriages" -- but would support extending benefits to same-sex couples only.

Traditional family advocates say extending benefits takes away an incentive to get married, and that unmarried couples lack the commitment of married ones. Their case is bolstered by sociologists Larry Bumpass, of the University of Wisconsin - Madison, and Linda J. Waite, of the University of Chicago, whose research shows unmarried couples are far less likely to stay involved over the long term, regardless of whether they've become parents.

Inclusive plans would likely benefit unmarried heterosexual couples far more than homosexuals. The Census Bureau estimates the number of unmarried cohabitants has growth from 523,000 in 1970 to almost 4 million in 1996.