Comparison of Urinary Iodine Excretion in Neonates and Their Mothers in Isfahan, Iran

Abstract

To determine the urinary iodine excretion of neonates (28 days of age or younger) and their mothers in Isfahan, a centrally located city in Iran, in 1997 after 8 years of iodized salt distribution in an effort to ameliorate iodine deficiency. Through a cross-sectional study and by means of convenient sampling, 146 mother-neonate pairs were selected among neonates born in Shahid Sadoughi Hospital in Isfahan. In order to eliminate the effect of povidone-iodine on breast milk and urinary iodine, Savlon antiseptic solution was used in normal vaginal delivery and on the umbilical cord. Normal values of urinary iodine concentration for the mothers and their neonates were > or = 10.0 microg/dL and >5.0 microg/dL, respectively. The data were analyzed and compared by the Student t test and Pearson correlation coefficient in SPSS software. P values <0.05 were considered statistically significant. In only 3% of the neonates and 14% of the mothers, urinary iodine excretion was below the normal range. No mother or neonate had severe iodine deficiency. In 2% of the mothers and 2% of the neonates, mild iodine deficiency was found. The mean urinary iodine concentration of neonates whose mothers were iodine deficient was significantly lower than that of neonates whose mothers were iodine sufficient (17.34 +/- 7.83 microg/dL versus 22.21 +/- 7.57 microg/dL; P<0.01). A direct significant correlation was noted between the urinary iodine excretion of neonates and that of their mothers (r = 0.37; P<0.01). The urinary iodine excretion in mothers paralleled the urinary iodine concentration of their neonates. If urinary iodine concentration is considered an index of total body iodine content, this study demonstrated that prolonged iodized salt intake has minimized the occurrence of iodine deficiency in Isfahan.