Apparent insufficiency of iodine supplementation in pregnancy.

Background: Pregnant woman are at increased risk for iodine deficiency, which may induce thyroid insufficiency and have damaging effects not only on the mother but also the fetus. We hypothesize that iodine supplementation during pregnancy reduces the risk for iodine deficiency.

Methods: Cross-sectional study to assess iodine levels in random urine specimens during pregnancy in New York City.