In January of 2007, the New York City Board of Health unexpectedly withdrew a proposal to allow city residents to change the sex on their birth certificates without undergoing sex-change procedures. Heath Commissioner Thomas R. Frieden, who enthusiastically supported the plan only a month before, told the New York Times that institutions like hospitals and jails raised concerns the board hadn't considered: Would female patients end up in hospital beds next to men? Would male inmates wind up in women's cell-blocks?

"This is something we hadn't thought through, frankly," Frieden admitted. "What the birth certificate shows does have implications beyond what the birth certificate shows."