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

ABSTRACT

BACKGROUND: 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. OBJECTIVE: To assess the correlation between MUIC and neonatal TSH levels. STUDY DESIGN: Cross-sectional. SETTINGS Tertiary care center in Delhi, India, between November 2015 to November 2016. PARTICIPANTS: Postnatal mother-neonate dyads. METHODS: 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: 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. CONCLUSION: Lack of correlation between neonatal TSH and MUIC is due to iodine excess together with iodine deficiency.