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

ABSTRACT

Background: Maternal urinary iodine concentration (MUIC) andpercentage of neonates with Thyroid stimulating hormone (TSH)>5 mIU/L are amongst the parameters suggested for assessingadequate iodine status.Objective: To assess the correlation between MUIC andneonatal TSH levels.Study design: Cross-sectional.Settings Tertiary care center in Delhi, India, between November2015 to November 2016.Participants: Postnatal mother-neonate dyads.Methods: TSH levels assessed among neonatal samples werestratified as below and above 5 mIU/L. MUIC was measured in544 mothers, 400 mother-neonate dyads with neonatal TSHlevels >5 mIU/L (cases) and 144 mother-neonate newbornmother 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%) weresignificant higher in cases than controls. Mean TSH was alsohigher (P=0.0002) in both the iodine deficient and iodine excessgroup. There was no correlation between neonatal TSH valuesand MUIC.Conclusions: Lack of correlation between neonatal TSH andMUIC is due to iodine excess together with iodine deficiency.