Proponents counter that there is no bias against girls in the United States. In fact, American couples are just as likely, if not more likely, to want a girl.
"We get roughly the same number of parents coming in who will request a boy as will request a girl," said David L. Hill, scientific director of the ART Reproductive Center in Beverly Hills, Calif. "It's not as if everyone is coming in wanting a male."
After bearing three girls, Kristen Magill tried for a boy -- and is having two.
(Laurie Swope For The Washington Post)
At MicroSort, 75 percent of parents have been seeking girls, Karabinus said.
Still, concern remains about the possibility of more subtle, emotional consequences. What happens in cases where, after paying thousands of dollars and suffering months of discomfort and inconvenience, parents are bitterly disappointed by a baby of the "wrong" sex?
"Consider the father who wants a boy in the hope of having as a son the athlete he had never been. Suppose the son isn't really interested in sports," Sandel said. "What sorts of expectations will burden a child who was designed with certain purposes in mind?"
These kinds of questions raise fears that the increasing ability to control and commercialize childbearing will fundamentally transform parenting.
"This is . . . a threat to the core value of parenthood that is usually expressed by the commitment to unconditional love," Gomez-Lobo said. "Our children should not be the result of our desires. We should love them as they are, not as we wanted them to be."
For their part, the Magills are looking forward to introducing their daughters to their little brothers.
"It's a good thing this is out there and available," Kristen said. "I don't think it's for everybody -- it takes money and patience and everything. But we felt like it was worth it. I'm sure having boys will be a different experience."