Embryo screening usually checks for abnormalities, but also predicts sex
Boy or girl? Almost half of U.S. fertility clinics that offer embryo screening say they allow couples to choose the sex of their child, the most extensive survey of the practice suggests.
Sex selection without any medical reason to warrant it was performed in about 9 percent of all embryo screenings last year, the survey found.
Another controversial procedure _ helping parents conceive a child who could supply compatible cord blood to treat an older sibling with a grave illness _ was offered by 23 percent of clinics, although only 1 percent of screenings were for that purpose in 2005.
For the most part, couples are screening embryos for the right reasons _ to avoid passing on dreadful diseases, said Dr. William Gibbons, who runs a fertility clinic in Baton Rouge, La., and is president of the Society for Assisted Reproductive Technology, which assisted with the survey.
"There are thousands of babies born now that we know are going to be free of lethal and/or devastating genetic diseases. That's a...