Evaluation of possible interactive factors with thyrotropin level in screening program of congenital hypothyroidism in Ahvaz

ABSTRACT

Accuracy and efficiency in screening program for congenital hypothyroidism [CH] in each geographical area requires regional studies and updating protocols. This study performed to assess factors possibly interactive with the result of screening test for CH in Ahvaz. During 19 months [Nov 2006-May 2008] all newborns in Ahvaz enrolled in screening by heel prick sampling for TSH then were referred for confirmation if it was >/= 5mIU/L. In next step, second assays considered as hypothyroid if TSH remained >/= 10 mlU/L. The factors were studied including age, history of hypothyroidism in mother, sex, birth weight [BW], birth number, feeding, parental consanguinity, TSH levels and duration of normalization of TSH. In totally of 35655 neonates were screened. 1162 cases [55.8%M, 44.2% F with p<0.001] recalled [3.25%]. Our study showed sex difference that was not significant in confirmed CH [82] cases [52.4% M,47.6% F with P=0.6], and also for TSH levels in both suspicious and confirmed individuals [P=0.55 and p=0.49 respectively]. The 90% of registered suspicious neonates were healthy, ad consequently discharged without treatment. Our study was shown hypothyroid neonates [3.7 +/- 1.8 kg] had no correlation with TSH [P=0.6 and p=0.3]. Also there were no correlation between TSH levels and the above-mentioned studied factors. If TSH level was high in screening test a longer time was needed for its normalization [P=0.03]. This study showed that suspicious and hypothyroid dominancy was mainly in boys with no relation to TSH. This suggests that healthy newborns suspicious to CH with elevated TSH need to be followed longer without treatment