Hearing evaluation of children with congenital hypothyroidism

Abstract

Objective: To evaluate the hearing function of children with congenital hypothyroidism (CH). Methods: A descriptive, quantitative, cross-sectional study carried out at NAMI in Fortaleza University, on 2006. Forty six children joined in the study, of whom 30 children with CH receiving hormonal replacement therapy with levothyroxine and 16 healthy children consisting of control group (CG). All the children had an auditory evaluation. The control group children were submitted to a TSH and free T4 level. Medical records were analyzed to determine the TSH and free T4 level, the beginning and the follow-up for children with CH. Results: Female gender prevailed in both groups, CH and CG, 23 (76.7%) and 9 (56.3%) children, respectively. The age group of the children with CH ranged from 3 months to 8 years old and the age group of the children from CG ranged from 4 months to 5.6 years old. The average for the beginning of the therapy with levothyroxine in CH children was 135.43 ±325.58 days. The other auditory tests were within the normal range and no statistically significant difference was found between the groups. Conclusions: Children with CH didn’t show any alteration in hearing threshold levels. They were first submitted to an auditory exam very late and the average time to start the therapy for CH was 4.5 months. This could contribute for the absence of hearing alterations at auditory evaluations, indicating that treated congenital hypothyroidism, even though not precociously, will not cause alteration in hearing threshold levels.