Endocrine Abstracts

Aim: To audit the current congenital hypothyroidism (CHT) management practice in our centre.

Standards: Guidelines published by UK Newborn Screening Policy and Standards in 2005 and ESPE in 1999.

Method: Retrospective audit from 2006 to 2010. The list was compared with the regional newborn screening lab to ensure data collection was complete.

Results: Thirty cases were referred to the unit giving local incidence of 7/10 000 births compared to 2.5/10 000 in UK. 28/30 were identified on Guthrie test and 2/30 on prolonged jaundice screen with normal Guthrie test. 67% were females. 50% were of South Asian (SA) ethnicity, 37% White Caucasian (WC) and 13% others compared to the local birth ethnic figures of 20% SA, 65% WC and 15% others. Data of 29 children were analysed (one child died related to prematurity complications). All had blood test to confirm diagnosis. 19/29 (65%) had thyroid radioisotope scan of which 52% demonstrated normal uptake (possible dyshormonogenesis) and 38% lingual/absent thyroid. 22/29 (75%) had CHT confirmed and 7/29 (25%) subclinical hyperthyrotropinaemia (SHT). Thyroxine tablet preparation at daily dose of 37.5 or 50 μg was used except 8/22 on 25 μg daily dose (<10 μg/kg per day). 7/8 who received 25 μg dose showed a pattern of delay in normalising TSH confirming inadequate dosage. Of the seven cases with SHT (TSH range from 5.1 to 36 mIU/l – reference=0.3–5 mIU/l), 3/7 went on to develop CHT requiring treatment (one had lingual thyroid) and 4/7 eventually normalised (range 5–28 weeks age).

Conclusion: The incidence of CHT in our local population is higher than the national figure with an increased incidence amongst SA. Initial thyroxine dose of <10 μg/kg per day (25 μg once daily) is inadequate. Two cases of CHT diagnosed on prolonged jaundice screen would not have been picked up if the recently published NICE guideline on jaundice was followed.