The results are thus compatible with the international recommendation that lactating women and infants younger than two years of age who reside in iodine-sufficient countries do not require iodine supplementation
BACKGROUND Iodine , an essential micronutrient , plays a critical role in normal growth and development , especially during the first two years of life .
This systematic review and meta- analysis is among the first to evaluate breast-milk iodine concentrations and infant iodine status in countries characterized by iodine sufficiency or deficiency .
Can postpartum maternal urinary iodine be used to estimate iodine nutrition status of newborns?
I deficiency can lead to detrimental effects , particularly in neonates and young infants . The aim of this study was to explore whether postpartum maternal urinary I can be used to estimate the I status of newborns . In this cross-sectional study conducted in Tehran , lactating mothers and newborns , within 3 - 5 d postpartum , were r and omly selected .  Urine sample s were collected from each mother and newborn , and a heel-prick blood sample was obtained from all newborns as part of the routine national newborn screening programme . According to the WHO criteria , median urinary I concentration ( UIC ) 5 mIU/l was considered as I insufficiency . A total of 147 postpartum women and neonates , aged 27·8 ( SD 5·3 ) years and 4·2 ( SD 0·6 ) d , respectively , completed this study  . The median UIC was 68·0 ( interquartile range ( IQR ) 39·4 - 133·5 ) and 212·5 ( IQR 92·3 - 307·3 ) µg/l in postpartum mothers and newborns , respectively . The median neonatal TSH was 1·00 ( IQR 0·50 - 1·70 ) mIU/l . There was no significant difference in the neonatal UIC and TSH of infants whose mothers had deficient and sufficient urinary I. In the multiple linear regression , neonatal UIC value was associated with maternal urinary I ( P=0·048 ) and parity ( P=0·039 ) ; a significant association was observed between neonatal TSH and infant sex ( P=0·038 ) and birth weight ( P=0·049 ) . The findings of our study demonstrate that , despite postpartum mothers being mildly I deficient , I status of their infants was adequate as assessed by UIC and TSH values . It seems factors other than maternal urinary I may influence the I status in newborns
The results are thus compatible with the international recommendation that lactating women and infants younger than two years of age who reside in iodine-sufficient countries do not require iodine supplementation
BACKGROUND Iodine , an essential micronutrient , plays a critical role in normal growth and development , especially during the first two years of life .
This systematic review and meta- analysis is among the first to evaluate breast-milk iodine concentrations and infant iodine status in countries characterized by iodine sufficiency or deficiency .