But for some couples, the cost and criticism are no match for the guarantee of having a boy or a girl.
"It's a huge happy thing," Steinberg said, describing the wall of thank-you cards and baby photos in his clinic. "Of course, any pregnancy is a huge happy thing. But some women out there are just obsessed with getting what they're after."
While the proportion of foreign patients at Steinberg's clinic is increasing, most of his business still comes from U.S. couples.
Kristen and John Magill are one such couple. Seven years ago, they used PGD with hopes of rounding out their girl-heavy brood.
"We had three girls and really wanted to complete our family with a boy," said Kristen Magill, who in 2004 had three carefully selected male embryos implanted in her womb. "We wanted a boy to carry on the Magill name."
The couple from Fallmouth, Mass., ended up having twin boys: John Magill the 3rd and Patrick.
"I know there are people who don't believe it should be done, but I don't really have an opinion," Kristen Magill said. "We did it for our own reasons."