Fertility Challenges – not “Designer Babies” – Drive Mushrooming Use of PGD Technique
Caseload is up tenfold in two years at one center. Fear of miscarriage appears to be most common motivation for couples.
MARGATE, FLORIDA – When a breakthrough treatment in reproductive medicine – preimplantation genetic diagnosis, or PGD – became widely available in the 1990s for treating a host of fertility and genetic disorders, some ethicists warned of a wave of so-called “designer babies,” in which couples would abuse the technique for selection of attributes such as gender and hair and eye color.
Less than a decade later, Americans are flocking to clinics offering PGD in mushrooming numbers but for a far more ordinary reason: to treat infertility with no diagnosed cause.
In PGD, infertility specialists create human embryos through in vitro fertilization (IVF) and then remove one or two cells from each for a biopsy. From these cells, laboratory experts can determine which embryos have the best chance of developing into a healthy baby after implantation into the womb.
At one of the nation’s busiest PGD laboratories, The Center for Preimplantation Genetics in Rockville, Maryland – which performs PGD analysis at the microscopic level for IVF Florida Reproductive Associates and nearly two-dozen other IntegraMed clinics nationwide – the rate of PGD cases last year doubled that of 2002, rising from 7 per month to about 14.
And for 2004, center officials are bracing for a breath-taking upswing: the caseload is projected to increase to nearly 70 per month by year’s end – 10 times the rate of 2002, when the center first opened.
The vast majority of cases are performed for couples struggling to avoid miscarriages, since PGD has proven highly successful for women who have suffered multiple miscarriages.
“Nine out of 10 of our cases come to us for analysis of chromosome abnormalities, the most common cause of previously unexplained infertility,” said William Kearns, Ph.D., the Center’s scientific director. The PGD technique allows reproductive geneticists to choose the healthy embryos over those with abnormalities, thereby reducing the risk of miscarriage.
The other 10 percent of cases are for couples wanting to conceive children free of an inheritable genetic disease known to be in a family’s history – a principle benefit of PGD that is touted increasingly by healthcare advocacy groups. Currently, PGD can be used to detect more than 200 genetic disorders such as cystic fibrosis, Duchenne muscular dystrophy and hemophilia.
“Advocacy organizations for such diseases have mounted intense public awareness efforts on behalf of PGD, which is having an effect, along with a general knowledge increase among infertility patients,” said Steven J. Ory, M.D., reproductive endocrinologist at IVF Florida.
“There’s no question there’s a rapidly increasing demand due to public education about PGD,” Ory said. “The learning curve has steepened remarkably in the last year or two.”
Although PGD does uncover the sex of an embryo, The Center for Preimplantation Genetics does not perform gender-only analysis. While highly controversial, gender selection and so-called “family balancing” are legal in the U.S. However, only a few infertility practices offer it and the American Society for Reproductive Medicine advises against it.
According to an April 2004 survey by Johns Hopkins’ Genetics and Public Policy Center, 61 percent of respondents said that they approved of genetically screening embryos for the purposes of helping a sick brother or sister, while 57 percent did not approve of using PGD for gender selection.
Preimplantation Genetic Diagnosis
How PGD is performed
Embryos are obtained two ways: either by combining an egg and sperm in the laboratory, or by flushing out the uterus five to seven days after fertilization. Once the embryo is isolated, a single cell is removed from each embryo under microscopic guidance and analyzed for the presence of genetic disorders. A diagnosis is obtained within a day or so of the test and only the unaffected embryos are replaced in the woman’s uterus.
Diseases PGD can detect include;
Alpha-1-antitrypsin deficiency
Cystic fibrosis
Fragile X syndrome
Lesch-Nyhan syndrome
Charcot-Marie-Tooth disease
Down syndrome
Tay-Sachs disease
Duchenne muscular dystrophy
Hemophilia A
Retinitic pigmentosa
Turner syndrome
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