High prevalence of maternal hypothyroidism despite adequate iodine status in Indian pregnant women in the first trimester.

Background: Iodine requirements are increased during pregnancy to maintain maternal and fetal euthyroidism. There have been recent improvements in iodized salt coverage in India, but whether iodized salt is sufficient to sustain iodine requirements during pregnancy remains uncertain. Our aims were to measure thyroid status in first trimester pregnant women in southern India and assess potential determinants of thyroid function, including iodine status, thyroid autoimmunity, dietary patterns, body weight, and anemia.

The iodized salt programme in Bangalore, India provides adequate iodine intakes in pregnant women and more-than-adequate iodine intakes in their children.

Objective: To compare the iodine status of pregnant women and their children who were sharing all meals in Bangalore, India.

Design: A cross-sectional study evaluating demographic characteristics, household salt iodine concentration and salt usage patterns, urinary iodine concentrations (UIC) in women and children, and maternal thyroid volume (ultrasound).

Setting: Antenatal clinic of an urban tertiary-care hospital, which serves a low-income population.