Autonomous University of Barcelona, Vall d’Hebron University Hospital, Clinic of Pediatric Endocrinology, Barcelona, Spain
Vall d’Hebron University Hospital, Clinic of Neonatal, Barcelona, Spain
J Clin Res Pediatr Endocrinol. 2022 Dec 1;14(4):453-462. doi: 10.4274/jcrpe.galenos.2022.2022-2-1. Epub 2022 Jul 21.
Preterm and low birth weight (LBW) neonates may present with thyroid dysfunction during a critical period for neurodevelopment. These alterations can be missed on routine congenital hypothyroidism (CH) screening which only measures thyroid stimulating hormone (TSH). The objective of this study was to evaluate a protocol for thyroid function screening (TFS) six years after national implementation.
Serum TSH and free thyroxine (fT4) were measured during the second week of life in neonates below 31 weeks. Patients with abnormal TFS (fT4 <0.8 ng/dL and/or TSH >5 mU/L) were followed up with repeated tests until normal levels were reported. Patients who were still on levothyroxine (LT4) at three years of age were re-evaluated.
Five-hundred and nine neonates were included. Thyroid dysfunction was detected in 170 neonates (33%); CH n=20 (3.9%) including typical CH n=1; delayed TSH elevation CH n=19; hypothyroxinemia of prematurity (HOP) n=15 (2.9%); and transient hyperthyrotropinemia n=135 (26.5%). Twenty-one neonates (4.1%) were treated (20 for CH and 1 for HOP). At 3-year follow-up only three patients were diagnosed with permanent CH and still need treatment. LBW infants tended to have TSH levels higher than those with adequate weight.
This protocol was able to detect thyroid dysfunction in preterm neonates who were not identified by the current program based on TSH determination in whole-blood. This thyroid dysfunction seems to resolve spontaneously in a few months in the great majority of neonates, but in some cases LT4 could be needed. There is a critical need for specific guidelines regarding the follow-up and re-evaluation of transient CH in preterm neonates.
早产儿和低出生体重儿（LBW）在神经发育的关键时期可能会出现甲状腺功能障碍。这些改变可能会在常规先天性甲状腺功能减退症（CH）筛查中被遗漏，该筛查仅测量促甲状腺激素（TSH）。本研究的目的是评估国家实施 CH 筛查六年后的甲状腺功能筛查（TFS）方案。
在 31 周以下新生儿生命的第二周测量血清 TSH 和游离甲状腺素（fT4）。异常 TFS（fT4<0.8ng/dL 和/或 TSH>5mU/L）的患者进行重复测试，直到报告正常水平。在三岁时仍服用左甲状腺素（LT4）的患者进行重新评估。
共纳入 509 名新生儿。170 名新生儿（33%）存在甲状腺功能障碍，包括典型 CH20 例（3.9%），包括 1 例典型 CH；延迟 TSH 升高 CH19 例；早产儿甲状腺功能减退症（HOP）15 例（2.9%）；和短暂性促甲状腺素血症 135 例（26.5%）。21 名新生儿（4.1%）接受了治疗（20 例为 CH，1 例为 HOP）。在 3 岁时的随访中，只有 3 名患者被诊断为永久性 CH，仍需治疗。LBW 婴儿的 TSH 水平往往高于体重充足的婴儿。
本方案能够检测到 TSH 全血测定不能识别的早产儿的甲状腺功能障碍。在大多数新生儿中，这种甲状腺功能障碍在几个月内似乎会自发缓解，但在某些情况下可能需要 LT4。对于早产儿短暂性 CH 的随访和重新评估，迫切需要制定具体的指南。
