Congenital hypothyroidism: the clinical profile of affected newborns identified by the Newborn Screening Program of the State of Minas Gerais, Brazil.

OBJECTIVE

To evaluate the clinical profile of newborns with congenital hypothyroidism identified by the Newborn Screening Program of the State of Minas Gerais, Brazil, between 2000 and 2006.

METHODS

Analysis of factors involved in this profile, including: TSH and FT4 levels (determined by chemiluminescence, with limits of normality set at 0.3-5.0 microUI/mL and 0.8-1.8 ng/dL, respectively), age at diagnosis and age at treatment. The study sample consisted of 443 children, 55.8% were female and 95% were seen before completing 60 days of life.

RESULTS

The most prevalent clinical signals were: umbilical hernia (51%), enlarged anterior fontanel (50.3%), and open posterior fontanel (47.2%). Hypotonia, macroglossia and feeding difficulties were the clinical signs most frequently associated with the biochemical severity of the disease. A delay in bone age was present in 32.1% of the children at diagnosis. The median of serum TSH and FT4 was 120 microUI/mL and 0.62 ng/dL, respectively. The median age at start of treatment was 28 days.

CONCLUSION

There are some early clinical signs that suggest a diagnosis of congenital hypothyroidism. Therefore, when presented with a child exhibiting these signs, serum TSH and FT4 should be assayed in order to confirm or rule out the disease, irrespective of the result of screening. Age at start of treatment remains high, but strategies are being implemented to reduce it.