In a study in western China, an area of severe
iodine deficiency and endemic cretinism, participants
were groups of children from birth to 3 years and
women at each trimester of pregnancy.16 Untreated
children 1–3 years of age, studied when first seen,
served as controls. The intervention was oral iodised
oil and treated children and the babies born to the
treated women were followed for two years. The main
outcomes were neurologic examination, head circumference,
and indexes of cognitive and motor development.
A small subsample was followed out to ª7 years
of age.17 The prevalence of moderate or severe neurologic
abnormalities among the infants whose mothers
received iodine in the first or second trimester was
2%, as compared with 9% among the infants who
received iodine during the third trimester (through
the treatment of their mothers) or after birth. Treatment
in the third trimester of pregnancy or after
delivery did not improve neurologic status, but
head growth and developmental quotients improved
slightly. Treatment at the end of the first trimester
did improve neurologic outcome. The prevalence of
microcephaly was 27% in the untreated children compared
with 11% in the treated children. The mean
(standard deviation) developmental quotient at 2
years of age was higher in the treated than in the
untreated children (90 14 vs. 75 18). In the longterm
follow-up study, development of children (range
4–7.3 years) whose mothers received iodine during
pregnancy, and children who received iodine first in
their second year, was examined.17 A second group of
children (range 5.8–6.9 years) whose mothers received
iodine while pregnant were examined 2 years later.
Head circumference was improved for those who
received iodine during pregnancy (compared with