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Latest Surrogacy News
Do IVF kids face more
health risks?
By Jacqueline Stenson
MSNBC CONTRIBUTOR July 21, 2003
July 21 —
In
the 25 years since the birth of the world’s first
“test-tube” baby, about a million children around the globe
have been conceived with the help of medical technology, and
experts say most of them are doing just fine. But with a
growing number of studies suggesting these kids may have
elevated rates of rare birth defects or other health
problems, U.S. doctors have formed a panel to take a careful
look at the safety of fertility techniques.
BORN IN ENGLAND on July 25,
1978, Louise Brown was the first child to be conceived
through in vitro fertilization. Since then, assisted
reproductive technology, or ART, has become more common with
thousands of children born each year. In 2000, the latest
year for which statistics are available, about 35,000 babies
in the United States were born using ART, accounting for 1
percent of all U.S. births.
Studies have yielded
conflicting results on the safety of these techniques, with
some reports showing that children conceived through ART are
no different health-wise than their naturally conceived
peers while other studies have raised concerns.
“What we needed was a group
of experts to really do an assessment about the strength and
power of the studies and what conclusions we could
reasonably draw about the risks,” says genetics expert Kathy
Hudson, director of the Genetics and Public Policy Center at
Johns Hopkins University in Baltimore and former assistant
director of the National Human Genome Research Institute.
Hudson partnered with the
American Society for Reproductive Medicine and the American
Academy of Pediatrics to convene a panel of experts who are
now analyzing the available research.
“Anytime a technique has
been associated, even suggested to be associated, with a
problem, I think it’s important to look at that association
to see if it’s real,” says Dr. Sandra Ann Carson, president
of the ASRM and a professor of obstetrics and gynecology at
Baylor College of Medicine in Houston. “Right now, we’re not
sure if it’s real.”
SUSPECTED PROBLEMS
During IVF, doctors place
egg and sperm cells together in a petri dish and then
transfer one or more of the resulting fertilized embryos
into a woman's uterus. With intracytoplasmic sperm
injection, or ICSI, a modification of IVF that was developed
in the early 90s to overcome male factor infertility,
doctors inject a single sperm - which may be immobile or
misshapen - into an egg.
Among the more recent
reports that have triggered some alarm over the techniques
are two large-scale studies published in the New England
Journal of Medicine over a year ago.
One study conducted in
Australia found that babies conceived through IVF or ICSI
were more than twice as likely as naturally conceived
infants to have major birth defects (9 percent vs. 4.2
percent), including problems with the heart and urinary or
genital tracts.
The second study by U.S.
health officials showed that children conceived through ART
were more than twice as likely as others to be born
underweight (6.5 percent vs. 2.5 percent), putting them at
risk for breathing difficulties and other potentially deadly
health problems at birth as well as developmental
difficulties down the line
The second study by U.S.
health officials showed that children conceived through ART
were more than twice as likely as others to be born
underweight (6.5 percent vs. 2.5 percent), putting them at
risk for breathing difficulties and other potentially deadly
health problems at birth as well as developmental
difficulties down the line.
Several other studies
followed. Last January, two reports published in genetics
journals found that children with Beckwith-Wiedemann
syndrome were four to six times more likely to have been
conceived through IVF or ICSI than not. The syndrome, which
normally affects one in 15,000 newborns, can cause an
oversized tongue and internal organs, high birthweight and a
greater risk of some cancers.
Also in January, a report
in The Lancet implicated IVF with a five- to seven-fold
increased risk of a rare form of eye cancer known as
retinoblastoma among children born in the Netherlands.
And, in the April issue of
the Journal of Urology, Johns Hopkins researchers concluded
that babies conceived though IVF were seven times more
likely to be born with a set of rare urological birth
defects that include the formation of the bladder outside
the body.
Other case reports linked
ICSI with Angelman syndrome, yet another rare condition that
can cause developmental problems and speech impairment.
To date, there have been
about 300 published reports involving children conceived
with ART, says Hudson, and the panel of experts will be
looking at all of them this summer. They plan to issue a
report in the fall with their conclusions and possible
directions for future research.
Britain, too, is taking
steps to better understand any potential dangers to children
from these techniques. Last fall, the government’s Human
Fertilization and Embryology Authority and the Medical
Research Council announced the creation of a working group
to explore the issue. The group’s report is expected later
this year.
‘SMALL DIFFERENCES’
While the studies linking
ART with health problems may seem scary, experts emphasize
that most of the observed abnormalities are rare to begin
with and therefore are still uncommon even if the risk is
magnified several times.
“You could hypothesize that
if there were a particular health problem that’s very
common, it would have been recognized early,” says Hudson.
“The risks that do exist,
if they do exist, are rare,” she maintains. Dr. Arnold
Strauss, chief of pediatrics at Vanderbilt University
Medical Center in Nashville and a member of the U.S. panel
analyzing the data, agrees.
“Common sense would say
that a lot of people have been through this and most of
their children are doing well,” says Strauss. “It’s
really a question of subtlety and small differences,” he
says.
What is clear is that ART
has not produced anywhere near the catastrophic results some
predicted a quarter century ago when Brown was born.
POSSIBLE FACTORS
Doctors do know that
because multiple embryos often are implanted during an IVF
cycle to boost the odds of success, a woman has an increased
risk of having twins, triplets or other multiples. These
babies are at risk for being born prematurely and
underweight. But it’s not known precisely why
singletons might be at risk for low birthweight or some of
the various birth defects or other problems that have been
identified in studies.
“Is it the disease, the
infertility, resulting in the birth defect or is it the
technique itself?” asks Carson.
Infertile couples who
undergo ART may have characteristics, such as defective
sperm or eggs, that put them at greater risk of having
children with abnormalities, experts speculate.
Strauss said he can see how
actual ART procedures could theoretically pose a risk.
“The speculation would be that you’re dealing with cells
that are put into conditions that they would never normally
see,” he says, referring to egg and sperm cells in a culture
medium in a lab dish. “Cells do change” in culture, he adds.
Experts say potential
problems could stem from other aspects of infertility
treatment, including the use of drugs to stimulate the
ovaries or maintain a pregnancy, the freezing and thawing of
embryos, or possible damage to an egg resulting from the
injection of sperm during ICSI.
As fertility specialists
sort out the risks, they say parents of children conceived
through ART or those contemplating fertility treatments
should not be overly concerned.
Dr. Zev Rosenwaks, director
of the Center for Reproductive Medicine and Infertility at
New York-Presbyterian Hospital in New York City, says he
explains to his patients that ART is still relatively new
and “while we don’t see a glaring increase in the
abnormality rate” there may be some, unclear degree of risk.
Both Rosenwaks and Dr. Alan DeCherney, a professor of
obstetrics and gynecology at the University of California at
Los Angeles and editor of the journal Fertility and
Sterility, say their patients aren’t deterred when they hear
about some of the recent studies. “They’re interested
in getting pregnant,” says DeCherney.
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