Background: Implementation of neonatal screening programs for congenital hypothyroidism (CH) has reduced related nosologies and has eradicated CH-associated mental impairment. With the decrease of the TSH cut-off limits employed to avoid false negative results, milder cases of CH are diagnosed. Obviously, in a number of patients, especially among milder CH cases, thyroid dysfunction is transient. The diagnosis of transient vs. permanent CH is established in time. No specific prognostic factors have been introduced allowing prediction of the outcome.
Objective and hypotheses: To identify the baseline characteristics influencing the outcome in neonates with CH. To formulate an algorithm that estimates the probability of transient CH in a given neonate based on specific data.
Methods: Data from the medical records of children diagnosed with CH by the Greek national screening program were analysed retrospectively. Patients were diagnosed during the last 35 years using variable TSH cutoff limits ranging from 30 to 6 mIU/ml. Laboratory, clinical and ultrasonographic data, as well as family history and geographical origin, were recorded and evaluated.
Results: A total of 1 051 children with CH were included in our study (569 male and 482 female, ratio 1.2:1). Of these, informative data were available in 844 patients. 15 children were diagnosed with a specific syndrome. In 20% of patients, a severe anatomical thyroid defect was disclosed. Among patients in whom an evident reason for permanent CH was not established (anatomic thyroid defect, known syndrome, etc), CH was transient in 33%. Percentage varies significantly among specific subgroups (e.g., 54% in premature IVF-conceived boys, 36% in premature normal-conception girls, etc).
Conclusion: The use of baseline characteristics and long-term data (e.g. sex, birth weight, mode of conception, initial TSH value, family history etc) from representative CH subgroups can help formulate a practical algorithm calculating the probability of CH being transient.
01 - 03 Oct 2015
European Society for Paediatric Endocrinology