Sonesson S E, Fouron J C, Leduc L, Lessard M, Grignon A
Astrid Lindgren's Children's Hospital, Karolinska Institute, Stockholm, Sweden.
Ultrasound Obstet Gynecol. 2000 May;15(5):407-12. doi: 10.1046/j.1469-0705.2000.00124.x.
No reference values exist concerning the differences between cardio-circulatory variables of normal twin fetuses. The normal data could be useful in the identification of conditions causing opposite hemodynamic effects on each twin.
To establish the normal differences among cardio-circulatory parameters of twin fetuses during the second and third trimesters of gestation.
Twenty-seven normal twin pregnancies were used in this longitudinal and prospective study. Doppler-echocardiographic investigations were performed every 2-3 weeks starting at an average of 23.11 +/- 3.13 (mean +/- standard deviation) weeks' gestation. At each visit, the following cardio-circulatory variables were evaluated: the cardio-thoracic ratio, the ventricular wall and septal thicknesses, end-diastolic and systolic diameters, ventricular fractional shortenings, velocity of circumferential fibre shortenings and left and right ventricular outputs. In addition the following measurements were made from Doppler recordings: through both aortic and pulmonary valve the acceleration and ejection times, the peak systolic velocities and the velocity time integrals; and through both mitral and tricuspid valves peak velocities of E and A waves and the E/A ratios. Finally the pulsatility index of the umbilical artery was also evaluated.
There was no single variable where the intertwin difference changed with gestational age. No systematic difference between the smaller and larger twin could be demonstrated for any variables except for the cardio-thoracic ratio.
Reference tables should permit a comparative approach between the two twins in the investigation of life threatening complications such as twin-to-twin transfusion syndrome.
目前尚无关于正常双胎胎儿心血管循环变量差异的参考值。这些正常数据可能有助于识别对每个胎儿产生相反血流动力学效应的情况。
建立妊娠中晚期双胎胎儿心血管循环参数的正常差异。
本纵向前瞻性研究纳入了27例正常双胎妊娠。从平均妊娠23.11±3.13（均值±标准差）周开始，每2 - 3周进行一次多普勒超声心动图检查。每次检查时，评估以下心血管循环变量：心胸比、心室壁和室间隔厚度、舒张末期和收缩期直径、心室缩短分数、圆周纤维缩短速度以及左右心室输出量。此外，从多普勒记录中进行以下测量：通过主动脉瓣和肺动脉瓣测量加速时间和射血时间、收缩期峰值速度和速度时间积分；通过二尖瓣和三尖瓣测量E波和A波的峰值速度以及E/A比值。最后还评估了脐动脉的搏动指数。
没有一个变量的双胎间差异随胎龄变化。除心胸比外，对于任何变量，较小胎儿和较大胎儿之间均未显示出系统性差异。
参考表格应有助于在调查诸如双胎输血综合征等危及生命的并发症时对两个胎儿进行比较。
