PARIS: Children conceived with the aid of fertility
treatments are more likely to be born with serious physical defects, according
an Australian study published Saturday.
Conception
using treatments like ovulation induction, in-vitro fertilisation or the
injection of sperm directly into an egg, resulted in serious defects in 8.3 per
cent of cases studied, the research team said.
The
corresponding ratio in spontaneous conceptions was 5.8 per cent -- a
"very" significant difference, lead researcher Michael Davies told
AFP of the University of Adelaide study published in the New England Journal of
Medicine.
"Something
that is not often talked about in the clinic, I suspect, is the risk of having
an abnormal baby. And so this emphasises this is something that must be talked
about between patients and clinicians.
"They
must discuss the risk for this when choosing the treatment."
Davies,
from the university's Robinson Institute for fertility, said the research had
focused on serious defects, "things that either require treatment or if
there is no treatment they are going to be considered handicapping", like
a heart condition or cerebral palsy.
The
study covered 308,974 births registered in South Australia between January 1986
and December 2002, of which 6,163 had resulted from assisted conception.
"I
don't think there is any reason it wouldn't be applicable to the majority of
clinics around the world," said Davies, calling for further research.
More
than 3.7 million babies are born every year as a result of fertility treatment.
The
survey, which researchers said was the most comprehensive of its kind yet,
found that not all treatments were equally risky.
The
scientists noted birth defects in 7.2 per cent of children born from in-vitro
fertilisation (IVF) and 9.9 per cent from intracytoplasmic sperm injection
(ICSI).
For
IVF, the percentage dropped significantly when taking into consideration
factors like parental age, smoking and other factors, but for ICSI it remained
high.
ICSI,
in which a sperm cell is injected directly into an egg, is a form of IVF --
which involves the fertilisation of an egg outside the body, in a laboratory.
Davies
said there were several theories on why ICSI was more risky -- possibly
involving the use of damaged sperm or damage caused by manipulation of the
sperm and egg in the lab.
With
IVF, the sperm entered the egg of its own accord.
"There
are factors associated with ICSI that require further research," he said.
The
researchers also found a tripling of risk in women using clomiphene citrate, a
drug for ovulation induction.
"While
confined to a small group in our study, this is of particular concern as
clomiphene citrate is now very widely available at low cost," said Davies.
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AFP/ck
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