For generations, people who wanted to choose their child's sex resorted, fruitlessly, to old wives' tales and folklore, such as the belief that eating more salty food or meat raises the odds of having a boy. But techniques developed to help infertile couples and to weed out genetic diseases have changed that -- the same procedures used to make sure an embryo is healthy can be used to determine its sex.
So far, most of the couples doing this either suffer from infertility or want to avoid passing on devastating genetic diseases, primarily ailments such as muscular dystrophy that afflict boys more often than girls. Only those who oppose creating embryos in the laboratory for any reason object to sex selection in such cases.
After bearing three girls, Kristen Magill tried for a boy -- and is having two.
(Laurie Swope For The Washington Post)
But a small number of clinics have begun offering the procedures to couples with no medical reasons -- who simply want to do the kind of "family balancing" the Magills sought or to plan the birth order of their children.
"The overwhelming number of couples who come in for this are couples who have three, four, five children in one gender and come to us and say, 'Will you guarantee us the opposite?' " said Norbert Gleicher, medical director of the Center for Human Reproduction, which has clinics in the New York and Chicago areas. "Why shouldn't patients have the right to choose this? It's one of the most basic rights in our society that we can build our families the way we wish."
The IVF procedure, which costs about $10,000 to $20,000, requires women to get hormone shots so doctors can retrieve eggs for fertilization in the laboratory. The lab harmlessly removes a single cell from 3-day-old, eight-cell embryos to test them. Only embryos of the desired sex are implanted into the womb. The process is almost infallible for picking sex and has the same overall success rate for producing a baby as standard IVF.
This approach, called PGD from its original use for "preimplantation genetic diagnosis," has been largely banned for nonmedical use in a number of countries, including Australia, Britain, Canada, France, Germany, India, Japan and Switzerland. In the United States, most fertility doctors say they refuse to do the procedure except for medical problems.
"My job is to help people make healthy babies, not help people design their babies. Gender is not a disease," said Ralph R. Kazer, a Northwestern University fertility doctor. "We would rather spend our time helping people who want to have babies who can't have babies."
With scientists rapidly identifying genes for various human traits, the potential for tailoring children in many other ways is becoming increasingly possible, critics say.
"It is the first step towards the concept of a designer baby," said George Annas, a Boston University bioethicist. "If you don't draw the line at disease, where do you draw the line? If gender is okay, it's hard to say any other characteristic we might be able to select in the future is off-limits."
But the doctors doing the procedures and independent experts say science is not even close to allowing parents to pick other traits -- and in all likelihood never will be.