Spanish
doctors found it was one of the most decisive factors in
the development
of
heart, kidney and urinary
tract defects.
Women should be aware of the dangers of
being overweight, they say. The researchers from Barcelona's
Hospital
de Sant Pau report their findings, based on 2,060 children,
in the journal Diabetologia.
Birth defects
It has long
been known that women who are diabetic before pregnancy
have a
higher chance of having birth defects that can lead to
heart and kidney
problems.
This is linked to the mother having high blood
sugar levels at a time when the embryo's organs are forming.
Babies
born to women with a condition called gestational diabetes
- diabetes triggered by pregnancy - are also at risk of
birth defects for the same reason.
The chance of damage
is slightly
lower because the mothers' blood sugar levels are usually
fairly unaltered.
Diabetes and obesity are closely linked.
However,
the latest study found the risk of birth defects seemed
to more closely related to a woman's level of obesity,
than
to the severity of her diabetes.
Dr Rosa Corcoy and colleagues
looked at the relationship between the mother's blood sugar
levels and weight and birth defects in more than 2,000
children born to women with gestational diabetes.
The mother's
degree
of obesity, measured by body mass index, appeared to be
the main predicting factor for heart defects in the unborn
child.
It was the only factor that predicted whether the baby
was likely to be born with kidney and urinary tract problems.
Previous
studies have not shown that obesity can increase the risk
of heart defects in the children of women with diabetes,
possibly
because this factor was not studied specifically, said
Dr
Corcoy.
Energy excess
She said one explanation was that
being obese
was an indication that the nutrients required for development
were in over-abundant supply. An excess of glucose and
other nutrients has been linked to birth defects before.
She said
the resistance to insulin that occurs in diabetes might
also be important. "This is just one of the problems that obesity
can have during pregnancy," said Dr Corcoy, from the Universitat
Autònoma de Barcelona.
She recommended women planning to have
a family consider their weight, but added: "It would not be
good to lose weight very quickly before pregnancy because of
the negative effects that could also have for mother and baby."
Amanda
Vezey, care advisor for Diabetes UK said: "This is an interesting
piece of research which reinforces the importance of being
a healthy weight. "We know that obesity is amongst the risk
factors which can make you more likely to have gestational
diabetes.
This research further highlights the importance of
trying to maintain a healthy weight when planning to become
pregnant." A spokeswoman from the National Childbirth Trust
said: "This study emphasises the need to address factors
that lead to overweight in young women as not only their
own health,
but that of their children could be affected."
"Often the most
unhealthy foods have the most promotion. Women need positive
information to make healthy choices for themselves and
their children. "However, individual women who are pregnant
and worried should remember that the proportion of babies
affected is small,
and discuss this with their midwife or doctor," she said.
Story
from BBC NEWS
Published: 2004/07/19
© BBC MMIV
