Abstract: Objective To understand the heel filter paper blood thyrotropin (TSH) level of preterm infants, and explore the appropriate screening time on preterm infants so that provide more exact diagnostic criteria to clinic. Methods A total of 4 606 specimens of preterm were seek out from more than one hundred specimens of neonatus borned in Beijing in 2011, and were divided into six groups according to different gestational age, screening time, birth weight, and established term infants group as control.TSH value was detected by DELFIA method, and distribution and the differences of TSH in preterm infants were analyzed between those groups by statistical software. Results The heel filter paper blood TSH level of preterm infants was lower than that of full-term infants as a whole, and very-low-birth-weight infants and extreme preterm infants in the exists obviously of individual differences, distribution was not balanced;The TSH level of preterm infants in delay screen over two weeks was declined, general preterm infants for overall balanced declined, extreme preterm infants and very-low-birth-weight infants in centered of level changed slightly, but department of percentileis was rise in terminal high value;The TSH cut-off of general preterm infants and full term infants were basically the same, but dropped significantly in extreme preterm infants and very-low-birth-weight infants, and also in delay screen over two weeks. Conclusion Establish TSH cut-off should consider different gestational age, birth weight and blood collection time of effect.

Key words: preterm infant, very-low-birth-weight infant, extreme preterm infant, thyrotropin, transient hypothyroxinaemia of preterm

摘要： 目的 了解早产儿足跟干血片促甲状腺激素(thyrotropin, TSH)水平, 探讨早产儿合适的筛查时机和切值, 为临床提供更好的诊断标准。方法 从 2011年收集的10万余份标本中选出早产儿标本4 606份, 以不同胎龄、采血时间和体重分组, 足月儿为对照组。采用时间分辨荧光免疫法测其干血片TSH值, 分析TSH水平分布及组间比对。结果 早产儿足跟干血片TSH整体水平低于足月儿, 极早早产儿和极低体重儿中存在明显的个体差异, 分布不均衡 ;早产儿在延迟2周采血后, 其TSH水平有所下降, 一般早产儿为整体均衡下降, 而极早早产儿和极低体重儿在百分位数居中的水平变化不大, 但在百分位数末端高值处则有升高;一般早产儿的TSH切值与足月儿基本一致, 而极早早产儿和极低体重儿的则有明显下降, 且在延迟2周采血后亦有明显下降。结论 制定TSH筛查切值应考虑不同胎龄、体重和采血时间的影响。

关键词: 早产儿, 极低体重儿, 极早早产儿, 促甲状腺激素, 暂时性低甲状腺素血症