Association Between Neonatal Thyroid Stimulating Hormone Status and Maternal Urinary Iodine Status

Abstract

Maternal urinary iodine concentration (MUIC) and percentage of neonates with Thyroid stimulating hormone (TSH) >5 mIU/L are amongst the parameters suggested for assessing adequate iodine status. To assess the correlation between MUIC and neonatal TSH levels. Cross-sectional. Tertiary care center in Delhi, India, between November 2015 to November 2016. Postnatal mother-neonate dyads. TSH levels assessed among neonatal samples were stratified as below and above 5 mIU/L. MUIC was measured in 544 mothers, 400 mother-neonate dyads with neonatal TSH levels >5 mIU/L (cases) and 144 mother-neonate newborn mother dyads with neonatal TSH <5 mIU/L (controls). Results: The percentage of mothers with iodine insufficiency (9.8% vs 5.6%) as well as iodine excess (54.3% vs 41.7%) were significant higher in cases than controls. Mean TSH was also higher (P=0.0002) in both the iodine deficient and iodine excess group. There was no correlation between neonatal TSH values and MUIC. Lack of correlation between neonatal TSH and MUIC is due to iodine excess together with iodine deficiency.