OBJECTIVE To examine the effect of antenatal corticosteroid administration (ACS) on fetal thymus growth in women who received ACS compared with gestational-age-matched controls. STUDY DESIGN Fetal thymus size and growth were measured in women at risk for preterm delivery who received ACS and compared with a matched cohort of women who were at low risk for preterm delivery and did not receive ACS. Fetal thymus perimeter and diameter were measured by 2-D ultrasound at baseline and every 2 weeks until delivery. RESULTS After adjusting for confounders, ACS exposure was associated with a significant reduction in thymus perimeter size (-0.70; 95% CI: -1.33, -0.07; P = 0.03). For every additional week of exposure, thymus growth trajectory was significantly decreased in ACS-exposed fetuses (P = 0.04). CONCLUSION The association between ACS and reduced fetal thymus growth should be further examined to establish the impact of ACS on childhood thymus development and immune programming.

中文翻译：

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产前注射皮质类固醇激素与胎儿胸腺生长减少有关：一项前瞻性队列研究。

目的探讨与妊娠年龄匹配的对照组相比，接受ACS的妇女的产前皮质类固醇给药（ACS）对胎儿胸腺生长的影响。研究设计在接受ACS的有早产风险的妇女中测量胎儿胸腺的大小和生长，并与匹配的队列中有低早产风险且未接受ACS的妇女进行比较。在基线时以及每2周直到分娩前，通过2-D超声测量胎儿胸腺的周长和直径。结果校正混杂因素后，ACS暴露与胸腺周长显着减少有关（-0.70； 95％CI：-1.33，-0.07； P = 0.03）。每增加一周的暴露，暴露于ACS的胎儿的胸腺生长轨迹就会明显降低（P = 0.04）。