Baltimore, MD (LifeNews.com) -- Genetic screening has come under fire from pro-life advocates because parents can use the process to destroy human embryos who carry any disability traits. However, a new study shows that a handful of parents use the screening process to purposefully give birth to children who have disabilities similar to their own.

Scientists at the Genetics and Public Policy Center at Johns Hopkins University are set to publish an article in an upcoming issue of the journal Fertility and Sterility on the subject.

Their publication will discuss how some parents use pre-implantation genetic diagnosis, or PGD, to screen for human embryos who have the same flawed genes.

Susannah Baruch and her colleagues, according to a New York Times report, surveyed 190 American PGD clinics and found that three percent of parents intentionally used PGD "to select an embryo for the presence of a disability."

Baruch says some parents don't see the conditions as disabilities or want their children to have an appreciation of the kind of disabilities they endure.

While critics may deride such decisions as intentionally trying to cripple children, it's nothing new.

The Washington Post in 2002 profiled a deaf lesbian couple who set out to have a deaf child by purposefully soliciting a deaf sperm donor.

"A hearing baby would be a blessing," Sharon Duchesneau told the newspaper at the time. "A deaf baby would be a special blessing."

However, some fertility clinics told the Times they find such practices unacceptable.

Robert Stillman of the Shady Grove Fertility Center in Rockville, Maryland, denies allowing parents to screen specifically for deafness or dwarfism.

"In general, one of the prime dictates of parenting is to make a better world for our children," he said. "Dwarfism and deafness are not the norm."

Yury Verlinsky of the Reproductive Genetics Institute in Chicago also refuses such requests and told the newspaper, "If we make a diagnostic tool, the purpose is to avoid disease."