Harris Birthright Centre for Fetal Medicine, Fetal Medicine Research Institute, King's College Hospital NHS Foundation Trust, London, United Kingdom (T.V.V., R.A., A.S., M.C., L.D.A., K.H.N., V.Z., J.M.S.).
Department of Congenital Heart Disease, Evelina London Children's Hospital, Guy's and St Thomas' NHS Foundation Trust, United Kingdom (T.V.V., M.C., V.Z., J.M.S.).
Circ Cardiovasc Imaging. 2018 Jul;11(7):e007575. doi: 10.1161/CIRCIMAGING.118.007575.
Assessment of the outflow tract views is an integral part of routine fetal cardiac scanning. For some congenital heart defects, notably coarctation of the aorta, pulmonary valve stenosis, and aortic valve stenosis, the size of vessels is important both for diagnosis and prognosis. Existing reference ranges of fetal outflow tracts are derived from a small number of cases.
The study population comprised 7945 fetuses at 13 to 36 weeks' gestation with no detectable abnormalities from pregnancies resulting in normal live births. Prospective measurements were taken of (1) the aortic and pulmonary valves in diastole at the largest diameter with the valve closed, (2) the distal transverse aortic arch on the 3 vessel and trachea view beyond the trachea at the distal point at its widest systolic diameter, and (3) the arterial duct on the 3 vessel and trachea view at its widest systolic diameter. Regression analysis, with polynomial terms to assess for linear and nonlinear contributors, was used to establish the relationship between each measurement and gestational age. The measurement for each cardiac diameter was expressed as a z score (difference between observed and expected value divided by the fitted SD corrected for gestational age) and percentile. Analysis included calculation of gestation-specific SDs. Regression equations are provided for the cardiac outflow tracts and for the distal transverse aortic arch:arterial duct ratio.
The study established reference ranges for fetal outflow tract measurements at 13 to 36 weeks' gestation that are useful in clinical practice.
流出道切面的评估是常规胎儿心脏扫描的一个组成部分。对于一些先天性心脏病，特别是主动脉缩窄、肺动脉瓣狭窄和主动脉瓣狭窄，血管的大小对于诊断和预后都很重要。现有的胎儿流出道参考范围是从少数病例中得出的。
研究人群包括 7945 名在 13 至 36 周妊娠期间无明显异常的胎儿，这些胎儿来自正常分娩的妊娠。前瞻性测量了（1）舒张期关闭时主动脉瓣和肺动脉瓣在最大直径处的大小，（2）在 3 血管和气管切面的远端升主动脉弓，在气管最远端的最宽收缩直径处，（3）在 3 血管和气管切面的最宽收缩直径处的动脉导管。回归分析采用多项式项来评估线性和非线性贡献，以建立每个测量值与胎龄之间的关系。每个心脏直径的测量值表示为 z 分数（观察值与预期值的差值除以拟合的 SD，SD 按胎龄校正）和百分位数。分析包括计算特定胎龄的 SD。为胎儿流出道和远端升主动脉弓-动脉导管比提供了回归方程。
该研究建立了 13 至 36 周妊娠胎儿流出道测量的参考范围，在临床实践中很有用。
