Jaruratanasirikul Somchit, Janjindamai Waricha, Sriplung Hutcha
Department of Pediatrics, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
J Pediatr Endocrinol Metab. 2019 Nov 26;32(11):1275-1282. doi: 10.1515/jpem-2019-0054.
Background Preterm infants are at high risk of developing congenital hypothyroidism (CH) due to the immaturity of the hypothalamic-pituitary-thyroid (HPT) axis, loss of iodine supply from the mother and preterm health problems. Objectives To study the incidence and etiologies of CH in preterm infants who were born or admitted in our institute during 2010-2015. Methods The medical records of preterm infants diagnosed with CH as defined by the thyroid-stimulating hormone (TSH) level at the time of the first or second screening >10 mU/L and/or free T4 < 1.00 ng/dL were reviewed. Results Of 2777 preterm infants, 73 cases (2.6%) were diagnosed as CH. The average TSH levels at the first and second screenings were 20.85 and 15.42 mU/L, respectively. The patients were treated with thyroxine at an average initial dosage of 15 μg/kg/day. At 2-3 years of age, after thyroxine discontinuation for 6-10 weeks and regular thyroid function tests for 2 years, 58 patients (79.5%) were diagnosed as having transient CH and 15 patients (20.5%) were diagnosed as having permanent CH. We found no clinical or laboratory parameters in the neonatal period that could differentiate permanent from transient CH. Thyroid scintigraphy (99 m pertechnetate) revealed two patients (13.3%) with ectopic thyroid, one with thyroid hypoplasia (6.7%), eight with normal thyroid (53.3%) and four with enlarged thyroid (26.7%). Conclusions CH was common in preterm infants with an estimated incidence of 2.6%. Thyroxine should be given to preterm infants with higher initial values of TSH >10 mU/L in order to prevent delayed treatment of permanent CH that could be confirmed later.
背景 由于下丘脑 - 垂体 - 甲状腺（HPT）轴不成熟、母亲碘供应中断以及早产相关健康问题，早产儿患先天性甲状腺功能减退症（CH）的风险很高。目的 研究2010 - 2015年在我院出生或入院的早产儿中CH的发病率及病因。方法 回顾首次或第二次筛查时促甲状腺激素（TSH）水平>10 mU/L和/或游离T4<1.00 ng/dL定义为诊断CH的早产儿的病历。结果 2777例早产儿中，73例（2.6%）被诊断为CH。首次和第二次筛查时的平均TSH水平分别为20.85和15.42 mU/L。患者接受甲状腺素治疗，平均初始剂量为15 μg/kg/天。在2 - 3岁时，甲状腺素停药6 - 10周并进行2年的定期甲状腺功能检查后，58例患者（79.5%）被诊断为暂时性CH，15例患者（20.5%）被诊断为永久性CH。我们发现在新生儿期没有临床或实验室参数可以区分永久性CH和暂时性CH。甲状腺闪烁显像（99m高锝酸盐）显示2例患者（13.3%）有异位甲状腺，1例有甲状腺发育不全（6.7%），8例甲状腺正常（53.3%），4例甲状腺肿大（26.7%）。结论 CH在早产儿中很常见，估计发病率为2.6%。对于TSH初始值>10 mU/L的早产儿应给予甲状腺素，以防止可能在后期确诊的永久性CH的延迟治疗。
