|
WEDNESDAY, Jan. 19 (HealthDayNews) -- In what they are calling a first, Australian scientists have used pre-implantation genetic diagnosis (PGD) to help a couple avoid having a baby with rhesus factor disease.
A healthy baby girl was born in November 2003 as a result of the procedure, according to a report in the European medical journal Human Reproduction.
The potentially fatal rhesus factor (Rh) disease is caused by an incompatibility between a mother's blood and that of her fetus.
The PGD procedure has been available for a while but apparently not used, said Dr. Joe Leigh Simpson, chairman of the department of obstetrics and gynecology at Baylor College of Medicine in Houston, on hearing of the Australian break-through.
"It's not a novel idea, but it's a good idea," added Simpson, whose institution is one that offers the procedure.
PGD has been used since the 1990s, mainly to detect single-gene diseases such as cystic fibrosis, to avoid diseases linked to the X chromosome and to scan for chromosomal disorders.
This is a new use of the technique, report the study authors, who are based in Sydney.
The case reported this week involved a 27-year-old married woman who already had one child with Rh disease. The woman underwent in vitro fertilization, 12 fertilized eggs were tested and two healthy embryos were transferred to her uterus. At 39 weeks, the woman delivered a healthy baby girl.
"This is just another in a long list of possible applications of embryo-screening techniques," said Dr. Jaime Grifo, director of the division of reproductive endocrinology at New York University Medical Center. Grifo was the first in the United States to successfully perform PGD, in that case, to avoid hemophilia. "It's an interesting application," he added.
"Using PGD to select out diseased embryos has been going on for a long time," Simpson added. "This is another in a long series of disorders."
With Rh disease, the mother's body identifies the baby's blood as "foreign" and develops antibodies against it. Those antibodies can destroy the red blood cells of the fetus and can cause jaundice, anemia, brain damage, heart failure and even, in some cases, stillbirth.
The disease, however, is becoming more rare. In the past 35 or so years, the incidence of Rh disease has been cut dramatically by the availability of anti-D immunizations given during pregnancy.
"Rh disease is not that common. It's not like it was 40 years ago," Simpson said. "There are other options."
According to the March of Dimes, not all women who need the immunization treatment get it, while some women do not benefit from it. Each year, approximately 4,000 babies in the United States are still born with Rh disease, down from about 20,000 in the 1960s.
According to the authors of the study, the procedure could be used by couples who already have a child with Rh disease. There is a tendency for the disease to worsen in subsequent pregnancies.
The only drawback, the authors said in a prepared statement, is that there may not be enough clinics that could perform the procedure. And they noted, the procedure itself can be expensive.
More information
The March of Dimes (www.marchofdimes.com ) has more on Rh disease.
|
.gif)
