Phonological acquisition in children with early-treated congenital hypothyroidism: association with clinical and laboratory parameters.

PURPOSE: To evaluate the phonological characteristics of children with congenital hypothyroidism (CH).

METHODS: Observational, analytical, cross-sectional, ambispective study including prepubertal children with CH (n=100; study group, SG) and controls without CH ( n=100; control group, CG). Assessments included a speech language pathology interview, the phonological evaluation of the ABFW Child Language Test, medical data, and neuropsychological tests in the first three years of life.

RESULTS: On treatment onset of the SG, the median chronological age of the participants was 18.0 days and 48.4% had total T4 <2.5 µg/dL (31.75 nmol/L). At the age of 7 years, children in the SG had higher rates of consonant cluster simplification and lower rates of complete phonological system compared to those in the CG. On analysis of combined age groups (4+5 and 6+7 years), the CG had a higher frequency of complete acquisition versus the SG. On multivariate analysis, thyroid agenesis, abnormal scores on the Clinical Linguistic and Auditory Milestone Scale and developmental quotient tests were associated with the occurrence of phonological disorders.

CONCLUSION: Children with CH present delay in phonological acquisition, despite early diagnosis and adequate treatment, especially between the ages of 6-7 years. The etiology of CH and the results of neuropsychological tests in the first years of life seem to be related to this delay.