The Frequency and Characteristics of Hypothyroidism Jaundice in Neonates with Hyperbilirubinemia; A Ten-Year Survey

Background & Aims: Congenital hypothyroidism is a serious disorder that could be treated if detected early. Jaundice is one of the symptoms of these neonates. However, the prevalence, clinical course and severity of jaundice are not yet well defined. We compared the clinical course and severity of jaundice in a case-controlstudy of congenital hypothyroidism and other neonates of unknown etiology who are yellow. Methods: The cross–sectional study was performed during 2002-2012 on 2780 four-day or older term neonates with jaundice. In addition to the usual procedures for diagnosis of jaundice, thyroid function was performed on 706 newborns referred to the neonatal or clinic part of Ghaem Hospital of Mashhad, Iran, and their thyroid function was evaluated. The clinical progress and severity of jaundice infected with hypothyroidism [thyroid-stimulating hormone (TSH) ≥ 10 µu/ml or T4 less than 8 µg/dl] compared with infants with jaundice of unknown cause. Results: The neonates' mean age was 16.03 ± 8.80 and 8.60 ± 6.10 days (P = 0.001), age of onset of jaundice was 4.00 ± 1.60 and 2.68 ± 1.75 days (P = 0.008), total bilirubin was 15.70 ± 5.25 and 21.88 ± 5.10 mg/dl (P < 0.001), length of hospital stay was 0.80 ± 1.11 and 3.37 ± 1.71 days (P < 0.001), age of the jaundice improving was 21.00 ± 15.23 and 49.40 ± 14.60 days (P = 0.080), T4 level was 5.80 ± 2.70 and 9.63 ± 2.26 µg/dl and TSH level was 22.56 ± 1.80 and 3.31 ± 1.69 µu/ml in groups of case and control, respectively. Conclusion: Based on the findings of this study, in infants presenting with jaundice, after the second week of life, evaluation of hypothyroid may be recommended.