Background: Congenital hypothyroidism (CH) is a major target of new born screening. It has two major forms (permanent and transient) that have different prognoses.
Objective and hypotheses: The purposes of this study were to assess the trends in incidence of permanent and transient CH in China, and to identify clinical variables that may help to distinguish these two forms of CH.
Method: Newborns were screened for CH at Xinhua Hospital of Shanghai Jiaotong University, Shanghai, China, from December 1983 to December 2012. Newborns diagnosed with CH were treated and followed.
Results: Among 1 187 906 newborns screened, 417 were diagnosed with CH. The overall incidence of CH was 1:2 849 newborns. The incidence more than doubled during the 30-year study period, Ptrend=5.8×10−10. The increasing incidence was observed for transient CH (Ptrend=0.006) but not for permanent CH (Ptrend=0.64). The ratio of transient to permanent CH was 0.52 overall and increased significantly during the study period (Ptrend=0.01); from 0.21 prior to 1997 to 0.71 between 2008 and 2012. Compared to transient CH patients, permanent CH patients with normal thyroids had a significantly lower birth weight (3.4 vs 3.2 kg) and higher thyrotrophic (TSH) levels at the time of screening (29.4 vs 41.6 μIU/ml). The AUC for discriminating these two types of CH was 0.63, and 0.64 for birth weight and TSH levels at the time of screening, respectively.
Conclusion: The incidence of CH increased in Shanghai, China, during the last three decades, and was attributable to the increase of transient CH.
18 Sep 2014 - 20 Sep 2014