Iodine deficiency in pregnant woman can affect growth and development of fetus. People who live in an area that had affected by previous iodine deficiency may continuously affect by abnormal thyroid function. The aim of the study is to assess thyroid function, that was measured by the concentrations of thyroid stimulating hormone, and its relationships with free thyroxine (fT4) among pregnant women in the two different geographic areas with previous history of iodine deficiency in Magelang, Central Java, Indonesia. Cross-sectional study was conducted in two types of location (replete and non-replete area) in Magelang, Central Java, Indonesia. A total of 243 aged between 15-45 y old with no pregnancy complication from two different geographics areas of iodine replete and sufficient were include in study. Blood biochemical markers such as free thyroxine hormone and thyroid stimulating hormone were assessed by Elisa method. Median of fT4 in non-replete and replete area was 1.18 (0.63-3.5) ng/dL; 1.12 (0.37-1.95) ng/dL, respectively. Whilst, median of TSH in replete area was 1.27 (0.09-8.21) ng/dL and non replete area was 1.3 (0.01-8.67) ng/dL. Correlation between fT4 and TSH showed significat relationship in non-replete area, r=-0.39 (<0.05), but it was not significant in replete area, r=-0.08 (>0.05). In addition, scatter plot showed the relationship between fT4 and TSH levels pattern in the replete area more widespread. Pregnant womens who live in areas that had affected severe iodine deficiency intake may have abnormal thyroid function but it still euthyroid maintain by adequate iodine intake.
Keywords: function; iodine; thyroid hormone.