ESPE Abstracts

Background: Neonatal hyperthyrotropinaemia (HT) is defined by elevated TSH and normal fT₄. HT is an increasingly common diagnosis and may be transient or permanent. There is a often a diagnostic dilemma whether to treat to prevent subclincal hypothyroidism or to wait thereby avoiding the risks of iatrogenic hyperthyroidism.

Objective and hypotheses: To examine a large population of infants referred to a tertiary centre over one year and determine prevalence, sex distribution and natural course of neonatal HT. In our study HT resolved in 76% of infants. We recommend watchful waiting with thyroid function tests repeated every 2 weeks.

Method: A 1 year retrospective study was conducted at Great Ormond Street Hospital between 2012–2013. Neonates with an abnormal screening test and a raised TSH (6–20 mU/l) and a normal fT₄ on confirmatory tests were included.149 babies were referred to the hospital with abnormal newborn screening tests. 123 had congenital hypothyroidism, 26 had neonatal hyperthyrotopinaemia. TFT’s were tested every 2 weeks in neonates with HT. Information was provided to parents about the importance of testing. Thyroid antibodies were evaluated in all babies with HT and were found to be negative. Thyroid scan was done when TSH was more than 15 mU/l and showed evidence of dyshormonogenesis in one. All babies were born at term. There was a male predominance (17/26). HT resolved in 8 weeks in 17 babies and in 12 weeks in three babies. six babies were started on thyroxine.

Results and conclusion: A diagnosis of HT was made in 17% of babies evaluated for an abnormal screening test in this study. In most cases HT appears to be transient, resolving in 76%.In the event of TSH rising above 20 mU/l, TSH remaining static or TSH and fT₄ decreasing correspondingly we started treatment (24%).We recommend watchful waiting in neonatal HT.