Introduction: In India, newborn screening (NBS) for congenital hypothyroidism (CH) is not yet a national government policy. Preliminary information suggests neonatal TSH levels to be higher in expatriate Indian babies than those in European populations in developed countries.
Objectives: To evaluate maternal urinary iodine and cord blood TSH in a subset of women participating in a postnatal NBS program for CH.
Methods: Cord blood (CB) and postnatal (PN) NBS samples (>24 h of age) were collected on Whatman 903 filter paper. Dried blood spot TSH assay was performed by immunofluorometry and urine iodine (UI) was estimated by the ammonium persulfate method.
Results: Mean±S.D. TSH in 4200 CB samples was 7.9±7.4 mU/l. TSH>20 mU/l was found in 4.6% of CB and 1.39% of 13 426 PN samples. Median UI in 350 mothers was 189 μg/l. Insufficient UI (<150 μg/l) was present in 42% women. Intake above normal (UI 150 to <250 μg/l) and excessive intake (UI>250 μg/l) were found in 22 and 20% of women respectively. TSH was weakly negatively correlated with birth weight, rural residence, and normal delivery, but not with UI.
Conclusion: Locally derived TSH cut offs are needed to deal with high recall rate. Iodine deficiency and low birth weight may be two contributory factors for high recall. Iodine nutrition is extremely inconsistent and variable in our women.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology