Chicago ? Correction: The Associated Press erroneously reported that a child in a similar case donated bone marrow to his sister. The boy, Adam Nash, donated umbilical cord blood to his sister, who suffered from a genetic disorder affecting her bone marrow.

In a growing practice that troubles some ethicists, a Chicago laboratory helped create five healthy babies so that they could serve as stem-cell donors for their ailing brothers and sisters.

The made-to-order infants, from different families, were screened and selected when they were still embryos to make sure they would be compatible donors. Their siblings suffered from leukemia or a rare and potentially lethal anemia.

This is the first time embryo tissue-typing has been done for common disorders like leukemia that are not inherited, and the results suggest that many more children than previously thought could benefit from the technology, said Dr. Anver Kuliev, a Chicago doctor who participated in the research.

“This technology has wide implications in medical practice,” Kuliev said Tuesday at a news conference.

The Chicago doctors said the healthy embryos that were not matches were frozen for potential future use. But some ethicists said such perfectly healthy embryos could end up being discarded.

“This was a search-and-destroy mission,” said Richard Doerflinger of the U.S. Conference of Catholic Bishops. The chosen embryos “were allowed to be born so they could donate tissue to benefit someone else.”

Valparaiso University professor Gilbert Meilaender, a member of the President’s Council on Bioethics, called the practice “morally troubling.” The council recently called for increased scrutiny of the largely unregulated U.S. infertility industry.

The cases involved prenatal tests called pre-implantation HLA testing, pioneered at Chicago’s Reproductive Genetics Institute.

The tests are an offshoot of pre-implantation genetic diagnosis, which has been done for more than 1,000 couples worldwide to weed out test-tube embryos with genetic diseases such as Down syndrome, or, more recently, for sex selection.

The institute’s doctors made headlines four years ago after performing embryo tissue typing plus genetic disease screening for a Colorado couple who wanted to create another baby to save their daughter, who had a rare inherited disease called Fanconi anemia. The resulting baby boy, Adam Nash, donated bone marrow in an operation doctors said was a success.

Since then, embryo tissue typing with genetic disease testing has been performed more than three dozen times worldwide, with most of the cases done at the Chicago institute, Kuliev said.

The cases, reported in today’s Journal of the American Medical Assn., involved nine couples who submitted embryos that underwent tissue-typing tests during 2002 and 2003. Five had infants considered suitable donors.

So far, stem cells from the umbilical cord blood of one infant have been donated to an ailing sibling, Kuliev said. He called the operation a success but said the older child would need continued monitoring to be sure.