Accusations about biased counselling
began flying almost before the ink was dry on the new
guidelines on prenatal screening from the Society of
Obstetricians and Gynaecologists of Canada (SOGC). The
recommendations themselves, published in early February,
are hardly groundbreaking — they essentially seek
to apply existing best practices in genetic screening
across the country — but the resulting media maelstrom
has revealed a serious schism in the way medical geneticists
think about the way physicians are counselling their
pregnant patients.
BEHIND
THE SCREEN
The SOGC is recommending that all pregnant women in
Canada be offered the choice of having non-invasive
prenatal genetic screening for fetal aneuploidy (including
Down syndrome, trisomy 18 and other genetic abnormalities),
and sets goals for better screening methods and guaranteed
counselling for patients who choose to undergo screening.
The difference between the new guidelines and the last
set, from 2001, is relatively minimal; the 2001 guidelines
said women should be offered screening if a counselling
program was available in the area to help inform women
about risk assessments and their options. The new guidelines
recommend that all women be offered screening and counselling,
in an effort by the SOGC to push the provinces to expand
their programs.
Dr Sylvie Langlois, a Vancouver
clinical geneticist and one of the authors of the SOGC's
new guidelines, says patients and doctors alike need
to consider all the choices available to them, from
whether to have the screening done to possible termination
of pregnancies. "It's a question of letting everyone
have the choice," says Dr Langlois of increasing access
to screening. "It's not a question of trying to have
perfect babies. We are trying to provide couples with
information about preparing for pregnancies with mental
illnesses."
The option to undergo blood-test
screening is important, explains Dr Langlois, because
it can determine whether diagnostic tests may be appropriate
to identify fetal aneuploidy, which can help prepare
obstetricians and surgeons for potentially complicated
deliveries. Up to half of children born with Down syndrome
are also born with heart defects that may require urgent,
highly specialized cardiac surgery. Duodenal atresia
and duodenal stenosis are also associated with Down
syndrome births. "Trisomy 18 can also cause problems
in labour," says Dr Langlois, "and knowing it exists
can influence an obstetrician's management of fetal
distress."
The new guidelines also describe
the minimum detection rate and maximum false-positive
rate of screening tests that may be used. Improving
the screening methodology should reduce the number of
amniocentesis tests performed to just a fraction of
the current figure, about 8%, with equal effectiveness
at diagnosing abnormalities, notes Dr Langlois. (Amniocentesis
is an invasive genetic test that results in the loss
of approximately 0.6% of the fetuses examined, according
to a recent literature review.) The new guidelines recommend
offering amniocentesis before screening only to patients
over 40 years old, whereas the previous guidelines had
a cut-off age of 35.
NEUTRALITY
AT ISSUE
Outspoken opponents of prenatal screening like the Canadian
Down Syndrome Society (CDSS) and McGill bioethicist
Dr Margaret Somerville have publicly stated the SOGC's
recommendations will lead to more abortions (Dr Somerville
has called genetic testing a "search and destroy mission")
and amount to eugenics. These charges are firmly denied
by Dr Langlois. But what really appears to be at issue
is the extent to which physicians influence patients'
decisions about whether they should request screening
or prenatal genetic diagnostics.
"A critical component of this screening
process is the context, the language and manner in which
these conversations about the possibility of Down syndrome
occur," said the CDSS in a release. "The CDSS is greatly
concerned that information provided to parents be clear,
accurate and unbiased." Doctors do not provide value-neutral
counselling, it went on, and their failure to do so
amounts to an implicit sanction of eugenics to eliminate
fetuses with Down syndrome.
The questionable neutrality of
counselling was confirmed by at least one of the medical
geneticists who served as a reviewer for the new SOGC
guidelines. "There is a problem with that," admits Dr
David Chitayat, the head of the prenatal diagnosis and
medical genetics program at Toronto's Mount Sinai Hospital.
He acknowledges that many physicians do not provide
non-directive counselling. "People are not educated
on how to counsel," he said. "We as medical geneticists
are trained to counsel and make sure it is non-directive,
but other physicians often do not know how to do it
and just tell patients what should be done." It's not
uncommon nowadays for the responsibility for counselling
to fall to family physicians.
FORTHCOMING
EVIDENCE
A systematic review of the international literature
on women's "decisional needs" in prenatal Down syndrome
testing is nearing completion by a group of Laval University
researchers. One of its conclusions, according to a
preliminary analysis presented at the Canadian Cochrane
Symposium in Ottawa on February 12, identifies a significant
gap in the knowledge of health professionals when it
comes to women's decision-making about genetic screening.
"Family physicians are not prepared
to counsel patients on test results," says Dr Sylvie
St-Jacques, one of the authors of the review, which
will likely be submitted for publication in April this
year. "Risk communication is geneticists' speciality."
In addition, doctors often don't take enough time to
thoroughly explain the tests and the results with their
patients, she says.
One problem that's been made clear
by the review, adds fellow author Dr Sonya Grenier,
is that Canada badly needs an oversight body to check
up on doctors who provide prenatal genetic screening.
DISSENT
AND DISAGREEMENT
Criticism of biased counselling was roundly dismissed
by Dr Langlois. "We know our counselling is non-directive
because 50% of patients don't choose to be screened,"
she says of her own practice, where she provides counselling.
Over the course of the past month, she says, two of
her patients decided to go ahead with their pregnancies
despite diagnoses of Down syndrome, after she counselled
them. "We provide a balanced view of Down syndrome,
and we give them information published by the Canadian
Down Syndrome Society, in fact."
But that may not be enough, says
Dr Chitayat. "I have a fear that even though there are
brochures and lots of information, that most women are
not being told about the choices. Patients can be quite
confused and most doctors don't counsel by asking what
they want. Many just tell them to get the blood test."
The optimal solution for Ontario
— he declined to speak about other provinces, though
he says many are similar — would be for the health
ministry to let doctors bill for group counselling sessions.
Genetic screening's complexity demands about an hour
with each patient, notes Dr Chitayat, but one could
just as easily counsel 20 patients during that hour.
If the system were streamlined like that, Dr Chitayat
says medical genetics experts would be able to provide
superior counselling for all patients who chose to have
prenatal screening, and family physicians without training
and experience on the topic would be off the hook.
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