**8. Follow-up**

Congenital anomalies are also more frequent in CH than in general population (10% in CH compared to 3% in general population) most common of these anomalies is cardiac malformation particularly pulmonary stenosis, atrial septal defect and ventricular septal defect. Adequate monitoring is required to maintain the thyroid functions within the recommended levels. The American Academy of Pediatrics recommends the following monitoring schedule [53].


• Four weeks after any change in dose or more frequently if results are abnormal or noncompliance is suspected.

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To ensure adequate growth and neurological development of the infant clinical evaluation should be carried out even more frequently than lab investigation.

#### **8.1. Unresolved controversy**

The incidence of congenital hypothyroidism is seemingly on the rise. Whether this increase is absolute or the result of lowering of screening test cutoff or changes in the racial and demographic profile or something else remains to be determined. This rise may also be the result of a larger reach of the screening test or the detection of infants with mild hypothyroidism and those with "delayed TSH rise". As already mentioned the most common cause of CH is thyroid dysgenesis, but the underlying etiology of thyroid dysgenesis remains an enigma. Only 2% cases of thyroid dysgenesis caused by genetic mutation in genes that encode for thyroid transcription factors. The other issue at hand is whether the rise of TSH is permanent or temporary we require more studies in affected infants detected by abnormalities on a second screening test to resolve this controversy.
