Psychomotor development assessment in pre-schooler children with primary congenital hypothyroidism

Abstract

Background: Congenital hypothyroidism (CH) is the most common neonatal disease and the main treatable and preventable cause of intellectual disability. Objective: The aim of this study is to assess psychomotor development in pre-schooler children with permanent primary CH. Design: Retrospective analysis of patients with CH, diagnosed through the neonatal screening program, between September 1996 and July 2018, and followed up in a tertiary hospital in Porto, Portugal, included in a cross-sectional study. Psychomotor development was assessed using Griffiths Mental Development Scale (GMDS) or Wechsler Preschool and Primary Scale of Intelligence (WPPSI) at age 2/3 years old and again at age 4/5 years old, by the same trained psychologist. Data regarding age at diagnosis, thyroid-stimulating hormone (TSH) level at diagnosis, initial levothyroxine dose, etiology of the primary CH, number of appointments in the first three years of life and levothyroxine dose supplementation by the time of the development scale assessment were abstracted from clinical records. Intellectual disability was defined as intellectual quotient (IQ) ≤69. Results: 62 patients were included in the study. Patients' median TSH level at diagnosis was 189,5 [19-727] mU/L. Median age at levothyroxine initiation was 11,5 [5-28] days with a median dose of 10,5 [7-19] ug/kg/day. The total IQ of children with CH at ages 2/3 years old (28,4 ± 9,0 months) was 99,743 ± 1,5 whereas at ages 4/5 years old (61,2 ± 12,1 months) was 103 [73-121]. None of the patients included in the study had IQ ≤69. Conclusion: No impaired psychomotor development/intellectual disability was found in pre-schooler children with treated CH.