Efforts are underway to change the way intersex children are treated: "The way that we took care of things in the past ... where there was a fair amount of secrecy, where there was surgery done in the infant state, and potentially irreversible surgery, is probably not the best way to go about things," said Dr. Earl Cheng, who runs the sex development disorders program at Chicago's Ann & Robert H. Lurie Children's Hospital, one of several nationwide.

It's a fitful evolution and a sign of the times, perhaps the natural next step in the gender-blurring evolution. Intersex conditions are often confused with gender identity issues, but they're different. Gender orientation refers to whether someone identifies as male, female, or something else; intersex involves reproductive anatomy. Some affected children have typical male or female chromosomes, but genetic glitches and hormonal problems that begin in the womb, cause genitals to resemble those of the opposite sex. Others have a male-female blend of sex chromosomes and reproductive organs.

Prevalence estimates vary, from more than 1 in 1,000 newborns, including conditions that involve mildly atypical genitals, to about 1 in 5,000 for more obvious cases. Experts say there's no evidence numbers are increasing, although rising awareness has led more families to seek treatment at specialty centers. Read More