Comparison of Cord Blood Thyroid Stimulating Hormone with Thyroid Stimulating Hormone Levels from Venous Samples on 3rd Day of Life in Detecting Congenital Hypothyroidism in Newborn- A Retrospective Study.

ABSTRACT

Congenital Hypothyroidism (CH) is one of the most common disorders related to mental impairment and growth retardation in newborns. The main objective of screening is to detect and treat them early so as to prevent or minimize the neuropsychological damage which can be irreversible if the treatment is delayed beyond the first few weeks of life. In our institution, we do concomitant T4 and TSH after 48 hours of birth for screening. This study is aimed at assessing the usefulness of cord blood thyroid stimulating hormone (CBTSH) screening compared to TSH on 3rd postnatal day. METHODSA retrospective study was done in 272 term neonates at birth to analyse the cord blood TSH levels and TSH levels were tested for on 3rd postnatal day. The values were statistically analysed using Fisher’s exact test.RESULTS272 babies were enrolled in the study. 17 (6.25%) babies had cord blood TSH above 20 mIU/ml and 11 (4.04%) babies had TSH values more than 10 mIU/ml in the 3rd day sample. The mean value of CBTSH was 9.68 microU/ml (SD +/-8.47) and that of 3rd day TSH was 3.76 microU/ml (SD +/- 3.17). 4 out of the 11 babies with elevated TSH levels on 3rd day was found to have congenital hypothyroidism on further follow up.CONCLUSIONSThis study reveals a high proportion of congenital hypothyroidism when compared to national and international references, thus highlighting the need for universal screening. According to our study, cord blood TSH cannot substitute the 3rd day TSH for diagnosing congenital hypothyroidism