'Selecting' Siblings to Help Sick Kids
Center Combines Fertility Technique, Tissue Typing to Choose Children With Lifesaving Stem Cells
Five More Births continued...
Researchers removed DNA from 199 eight-cell embryos following in vitro fertilization and analyzed them for tissue compatibility with the sick children. Twenty-eight matching embryos were transferred, resulting in the birth of five healthy children whose tissue matched that of their siblings.
If the couples had conceived naturally, they would have had a 25% chance of giving birth to a child whose tissue matched his or her sibling.
"Prior to this technology, tissue matching could only be done after implantation," study co-researcher Anver Kuliev, MD, PhD, tells WebMD. "Obviously interrupting the pregnancy because the fetus is not a match is a poor option."
While there are legitimate "Brave New World" concerns surrounding new technologies that allow parents to select the traits of their children, bioethicists contacted by WebMD say they have few concerns about using preimplantation genetic diagnosis to avoid life-threatening genetic illnesses and possibly save sick family members.
In an editorial accompanying the study, Norman C. Fost, MD, addressed the criticism that as preimplantation genetic diagnosis becomes more refined, people may use it to select trivial traits like eye color. This "slippery slope" argument, he notes, can be made with just about all new technology, "since new technology almost always has undesirable consequences." Fost directs the program in medical ethics at the University of Wisconsin and is the former chairman of the American Academy of Pediatrics Committee on Bioethics.
Ethicist Josephine Johnston says that given the expense and poor success rate of IVF, it is unlikely that couples will choose it over natural conception for frivolous reasons. Johnston is an associate for ethics law at the Hastings Center for bioethics research in New York's Hudson River Valley.
"With the trauma and uncertainty involved with IVF, people certainly aren't clamoring to do it if they can conceive naturally," she says. "But the concern about designer children may become more real if the success rate for IVF improves."
'The Best Outcome'
Lisa Nash says she and her husband heard all the criticisms but consider preimplantation genetic diagnosis a godsend that gave the Colorado couple the option of having a desperately wanted second child that could, as an added bonus, help make their first child well.
It took them five IVF attempts, at a cost of more than $80,000, to have Adam and two other attempts to have a third child 13 months ago.
"My worst fear was that I would have other kids who would only know Molly through pictures, or that my husband and I would have never had any other children because of the risk of passing this illness on," she says. "Out of the possible scenarios, this technology gave us the best outcome imaginable."