Gámez Francisco, Rodríguez María José, Tenías José María, García Javier, Pintado Pilar, Martín Raquel, Pérez Ricardo, Ortiz-Quintana Luis, De León-Luis Juan
Department of Obstetrics and Gynecology, Hospital General Universitario Gregorio Marañón, Universidad Complutense de Madrid, Madrid, Spain (F.G., P.P., R.M., R.P., L.O.-Q., J.D.L.-L.); and Department of Obstetrics and Gynecology (M.J.R., J.G.) and Research Support Unit (J.M.T.), Hospital la Mancha Centro, Alcázar de San Juan, Ciudad Real, Spain.
J Ultrasound Med. 2015 Apr;34(4):577-84. doi: 10.7863/ultra.34.4.577.
The purpose of this study was to estimate reference ranges for the pulsatility index (PI) of the fetal aortic isthmus in uncomplicated singleton and twin pregnancies during the second half of pregnancy.
We conducted a cross-sectional observational study involving 543 healthy fetuses: 361 singleton pregnancies and 182 twin pregnancies between 19 and 36 weeks' gestation. The aortic isthmus PI was measured in 2 sonographic planes: the longitudinal aortic arch view and the 3-vessel and trachea view. We evaluated the reproducibility of aortic isthmus PI measurements between these planes by calculating intraclass correlation coefficients and limits of agreement. Scans were performed by 2 physicians, and intraobserver agreement was also measured. Regression analysis was used to estimate gestational age reference values for the aortic isthmus PI.
The aortic isthmus PI was significantly correlated with gestational age in singletons and twins during the second half of pregnancy (P < .01). We did not find significant differences between reference ranges in singletons and twins or between the sonographic views.
This study offers reference ranges for the aortic isthmus PI during the second half of gestation in singleton and twin pregnancies. Mean aortic isthmus PI values were similar in both types of gestations as well as both sonographic views. The aortic isthmus PI may be reliably obtained from either sonographic view.
本研究旨在评估妊娠后半期单胎和双胎妊娠中胎儿主动脉峡部搏动指数（PI）的参考范围。
我们进行了一项横断面观察性研究，纳入了543例健康胎儿：361例单胎妊娠和182例双胎妊娠，妊娠周数在19至36周之间。在两个超声平面测量主动脉峡部PI：主动脉弓纵切面和三血管气管切面。我们通过计算组内相关系数和一致性界限来评估这些平面之间主动脉峡部PI测量的可重复性。扫描由两名医生进行，同时也测量了观察者内一致性。采用回归分析来估计主动脉峡部PI的孕周参考值。
妊娠后半期单胎和双胎的主动脉峡部PI与孕周显著相关（P <.01）。我们未发现单胎和双胎的参考范围之间或超声切面之间存在显著差异。
本研究提供了单胎和双胎妊娠后半期主动脉峡部PI的参考范围。两种妊娠类型以及两个超声切面的主动脉峡部PI平均值相似。从任一超声切面均可可靠地获得主动脉峡部PI。
