Background: Screening for congenital hypothyroidism (CH) with the possibility of an early treatment has transformed the outlook for children with CH. Despite the unquestioned public health success of newborn screening programs, the management of CH is still controversial. Most patients with positive screening have permanent hypothyroidism but some of them may have transient hyperthyreotropinemia, so it is important to identify these patients in order to avoid lifelong unnecessary treatment.
Objective: To identify factors useful to distinguish between children with permanent congenital hypothyroidism and transient (TH) o permanent hyperthyreotropinemia (PH).
Method: We enrolled 54 children with positive screening test for CH. All these patients have been treated with levo-thyroxine at a dose of 1012 μg/kg per day up to three years when treatment has been discontinued and the diagnosis was rechecked. Comparison between different parameters in the three groups was performed by one-way ANOVA and χ2.
Results: Table 1.
|TH (n=23)||PH (n=10)||CH (n=21)||P|
|Gestational age (weeks)||36.4||37.5||38.1||0.117|
|Birth weight (g)||2590||2700||2900||0.270|
|TSH at diagnosis (mIU/ml)||81.5||105.2||82.4||0.842|
|FT4 at diagnosis||9.5||9.0||12.7||0.720|
|Levo-thyroxine at diagnosis (μg/day)||31.19||32.0||29.81||0.899|
|Levo-thyroxine adjustment||0/23 (0%)||0/10 (0%)||12/21 (57%)||0.0001|
|Levo-thyroxine at 1 years (μg/kg per day)||2.31||2.93||3.02||0.154|
|Levo-thyroxine at 3 years (μg/kg per day)||1.33||1.70||2.67||0.0001|
Conclusion: Our data demonstrate that none of the considered parameters was able to predict differential diagnosis among CH and either TH or PH before the age of 3 years, with the only exception of levo-thyroxine dose adjustments that were necessary only in CH patients; as a consequence of levo-thyroxine adjustment, levo-thyroxine dose at the age of therapy withdrawal was significantly higher in CH patients than in the other groups. When TH or PT is suspected early cessation of therapy should be considered in order to reduce medical expenses and parental anxiety.
18 Sep 2014 - 20 Sep 2014