ABSTRACT

The aim of this study was to evaluate the risk factors leading to congenital hypothyroidism (CH) and to determine the appropriateness of the cut-off value used in screening in our country.

To investigate the risk factors, mothers of 84 newborns diagnosed with CH and 188 normal newborns as control group out of newborns in whom heel lance was performed in the National Newborn Screening Program (NSP) in Ankara in 2009 were enrolled in a survey to perform a nested case-control study.

A statistically significant association with consanguineous marriage, history of threatened abortion, presence of thyroid disease or CH in family members was observed in newborns with CH. The second component of our study was related to the power of screening test. When the cut-off value was taken as 15.05 mlU/L in the analysis of heel lance performed “between 2nd and 6th days after birth” using the test for CH in screening laboratories in our country, sensitivity and specificity of the test was observed as 77.1% and 97.3%, respectively. This supports the appropriateness of the current cut-off value defined as “15 mlU/L” for our country used in NSP workflow.

Risk factors observed in this study and definition of the cut-off value as 15.05 mU/L in screening test are highly significant in establishing health policies for NSP in our country.