Endocrine Abstracts

Introduction: Congenital hypothyroidism (CH) is defined as thyroid hormone deficiency which is present at birth. Thyroid hormones are crucial for early neurodevelopment. Untreated severe CH results in major neurological deficits. Therefore, if treatment is initiated early, these deficiencies can be prevented. Newborn screening for CH was first initiated in Sri Lanka in September 2010.

Methods: A retrospective cohort study was carried out in the Endocrinology clinic at the Lady Ridgeway Hospital for Children. Data was obtained using the clinic records of children who were referred as having abnormal Thyroid Functions from January 2012 to January 2022 using a researcher administered questionnaire. Sample size was calculated using Lwanga and Lemeshow equation and study sample calculated as 73.

Results: When demographic factors were analysed, out of 73 cases, 50.7% were female and 49.3% were male. 84.7% were Sinhalese, while 8.2% Muslim, 4.1% Tamil and 2.7% belonged to other ethnicities. Out of the CH babies, 8.2% were born to mothers were diagnosed with thyroid illnesses and 2.7% were born to consanguineous parents. 84.9% babies diagnosed with CH were born at term while 15.1% were born preterm. 8.2% of babies with CH had Trisomy 21. 54.2% were identified by newborn screening within 2 weeks from birth and 50.7% were started on treatment with Levothyroxine within first 2 weeks of birth. 31.5% were identified between 2 weeks to 1 month and 35.6% were started on treatment between the same time frame. Clinical features led to the diagnosis of 12.3% while 50.7% were informed via their local medical officer of health and 37.1% were informed from the hospital of birth. On neonatal screening TSH was identified as >100 mU/L in 47.9% and 27.4% had TSH between 40 and 100 mU/L. 20.5% had TSH between 20 and 40 mU/L whilst 4.1% were between 6 and 20 mU/L. Ultrasound scan findings include 31.5% with aplasia, 12.3% with hypoplasia and 4.1% with ectopic location. Thyroid gland was normal in 52.1%.

Conclusion: Our analysis helped to identify the factors linked with Congenital Hypothyroidism and also assessed the efficacy of the neonatal screening program over the past decade in Sri Lanka.