[An approach to a sanitary and social problem: urinary iodine excretion in pregnant women from a iodine deficient region].

The urinary iodine excretion (UIE) assay is an effective method to detect reduced iodine intake. UIE was measured in two different samples (morning and evening) from 121 pregnant women, with a turbid-metric method modified by Pino (normal value =150 ugl/1). Furthermore, thyroid function was evaluated in pregnant women with UIE <100 ug/l. From 121 pregnant women, the UIE was normal in 75 with similar morning and evening samples (morning: 305.2 +/- 7.0; evening: 319.2 +/- 8.8; p: NS). The UIE did no showed differences in different trimesters and in morning and evening samples. The UIE was low in 46 women (36.9%), without significant differences between morning and evening (morning: 88.12 +/- 5.07 microg/l; evening: 88.7 +/- 6.2 microg/l; p: NS). Normal or low UIE were not influenced by the age of pregnant women and 45% of pregnant women with UIE < 100 ug/l showed impaired thyroid function. Morning and evening study of UIE allowed us to detect a higher number of pregnant women with low iodine intake. This study let us to find thyroid function abnormalities likes a screening method, because in our state there is not a public screening program for gestational hypothyroidism.