Evaluation of the Incidence of Neurodevelopmental Disorders in Children Aged 1 to 3 Years with Congenital Hypothyroidism Treated with Levothyroxine

Objective (s): To assess the incidence of neurodevelopmental disorders in children aged 1 to 3 years with congenital hypothyroidism treated with Levothyroxine. Methods: In a historical cohort study, 122 neonates with congenital hypothyroidism under treatment with levothyroxine and 122 healthy children aged between one and three years were evaluated by the ASQ questionnaire for their neurodevelopmental status. Sampling was done non-randomly. In the exposure group, questionnaires were asked by telephone or they were invited to the clinic for an assessment period after contact with them. In the healthy children group (control group), children who were referred to the clinic for periodic examinations were selected. Results: Overall 17.2% of children with congenital hypothyroidism and 12.3% of health children failed to obtain tershold score for developmental test giving a relative risk of 1.4, but the risk was was not significant. Conclusion: The study showed that children with congenital hypothyroidism would develop normally if diagnosis and initiation of treatment starts at age under one month. The prescribed dose of 10 micrograms per kilogram of baby weight at the start of treatment and adjusting the dosage of the drug correlate with the age and weight of the child and continuing until the age of three, will lead to normal development in children.