:: Volume 2, Issue 4 (12-2000) ::
2000, 2(4): 263-277 Back to browse issues page
High prevalence of neonatal hypothyroidism in Tehran
A Ordookhani , M Hedayati, P Mirmiran, R Hajipour, F Azizi
Abstract:   (43370 Views)
Abstract: Preliminary studies denote that screening for congenital hypothyroidism (CH) is feasible in Iran due to elimination of iodine deficiency and resulting decreased hyperthyrotropinemia and recall rate. In this article the incidence rate of neonatal hypothyroidism, managerial processing and operational feasibility are discussed. Six general hospitals of Tehran, and one hospital and a delivery center under the coverage of PHC in Damavand district health network were set for cord blood specimen collection on filter paper. Specimen collection and transportation to Endocrine Research Center central lab were performed according to NCCLS and Wisconsin newborn screening program guidelines. TSH values ≥20 mU/L were recalled, venous TSH and T4, maternal and neonatal urinary iodine concentration were measured between 7-14 days of life. Hypothyroidism was confirmed by venous TSH more than 10 mU/L and T4 less than 6.5 μg/dl. Hypothyroid newborns underwent thyroid scanning, using 99mTc pertechnetate and radiographic imaging for detection of probable delayed bone age. Thereafter, L-T4 replacement therapy began promptly. 16124 neonates were screened from Feb 20, 1998 to Mar 20, 2001(37 months). 90% of total births were covered. 0.2% of all specimens were unsatisfactory for TSH testing. Recall rate was 1.4%. 17 cases were hypothyroid (Incidence rate was 1: 950 births). Mean and SD for the interval between birth to starting L-T4 treatment was 11± 5 days. Median maternal and neonatal iodine excretion were 18.3 (8-40) and 38.9 (7.8-45) μg/dl, respectively. Among CH newborns, 12, 2, 0, and 3 cases had cord blood TSH values >100, 50-100, 40-50, and 20-40 (mU/L), respectively. There were consanguineous marriages between parents of 11 hypothyroid cases. The screening program for CH is feasible and highly effective in both PHC and non-PHC systems in Tehran and Damavand because of high coverage of total births, minimal rate of unsatisfactory cord blood samples, short interval between birth to starting treatment, and low recall rate. High incidence of neonatal hypothyroidism, which may be due to consanguineous marriages necessitates a national screening program.
Keywords: Neonatal screening, Cretinism, Congenital hypothyroidism, Cord blood, TSH
Type of Study: Original | Subject: Endocrinology
Received: 2006/11/30 | Published: 2000/12/15

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Volume 2, Issue 4 (12-2000) Back to browse issues page