May 26, 2006
Study questions need for iron in pregnancy
NEW YORK (Reuters Health) - Children whose mothers take
iron supplements while pregnant don't have higher IQs than
those whose mothers didn't take iron pills, a study from
Animal studies have shown that iron deficiency in pregnancy
-- usually more severe than the anemia that may strike pregnant
women -- can cause brain damage in offspring, Dr. Maria
Makrides of Women's & Children's Hospital in North Adelaide and
Doctors in many industrialized nations routinely advise
pregnant women to take iron supplements, they add, but the
evidence for their benefits is not clear. In fact, they note,
the US Preventive Task Force has called for studies to look at
whether iron supplementation does in fact have any effect on
To investigate, Makrides and her team assigned 430 pregnant
women to take 20 mg of iron daily or a placebo beginning at 20
weeks of gestation through delivery. They then evaluated the
children's behavior and intelligence at four years of age.
At the end of pregnancy, 1 percent of the women who took
iron had anemia, compared to 11 percent of those who did not.
There was no difference in IQ between the iron group and
the placebo group.
However, 16 percent of children whose mothers took iron had
an abnormal behavior score, compared to 8 percent of children
in the placebo group. This finding "needs to be interpreted
with caution," the researchers write, as it could have been due
to chance rather than the effect of iron supplementation.
Accidental overdose with iron supplements is a common cause
of poisoning in children, Makrides and her colleagues point
"From a public health perspective, the lack of apparent
clinical benefit and the potential hazards associated with
routine iron supplementation in pregnancy suggest that the
risks may outweigh the benefits in well-nourished populations
in whom the incidence of iron-deficiency anemia at the end of
pregnancy is about 11 percent," they conclude.
SOURCE: American Journal of Clinical Nutrition, May 2006.