Excreção urinária de iodo em lactentes segundo as características pós parto Urinary excretion of iodine in infants in relation to characteristics at and after childbirth

Objective: To evaluate the concentration of iodine in the urine of infants (ioduria) and its possible relation to the postpartum characteristics of the newborn infant, and to assess the concentration of iodine in table salt, since this is the food with the highest content of this micronutrient ingested by the population. Methods: 32 infants under 6 months of age participated. The analysis of iodine in urine was based on the Sandell-Kolthoff reaction (1937) and that in salt on the titration method recommended by the National Health Foundation (Funasa). Postpartum infant characteristics were collected by means of a questionnaire answered by the nursing mothers. A descriptive statistical analysis was carried out. To compare the average ioduria of the infants in terms of the variables: type of delivery, breastfeeding, pregnancy and use of supplement, the Student t-test was applied. Associations of interest were examined by Fisher's exact test. The criterion of significance was p0.05. Results: The mean height and weight of the infants at birth were 47.5 cm and 3.2 kg, respectively. Most infants received exclusive breastfeeding, took no supplement, were born at term and by cesarean section. The median urinary iodine found in the infants was 190.78 mg /L and the average concentration of iodine in the salt was 75.59 mg I /kg salt. There was no correlation between the iodine content in salt and ioduria in infants. Conclusion: The median urinary iodine was found to be adequate, but the concentration of iodine in salt was excessive. There were no significant relationships between the postpartum characteristics of the infant and urinary iodine.