Kim Suk Young, Lee Soon Pyo, Lee Chae Min, Jung Sun Young, Park Han Na
Department of Obstetrics and Gynecolgy, Gachon University Gil Medical Center, Incheon, Korea.
Obstet Gynecol Sci. 2015 Jan;58(1):17-23. doi: 10.5468/ogs.2015.58.1.17. Epub 2015 Jan 16.
The purpose of this study was to investigate the aortic isthmus (AoI) flow difference between larger fetus and smaller fetus of twin; and to evaluate the predictive value of early diagnosis of hemodynamic change in twin growth.
This prospective study on 49 pairs of twin fetuses was performed to obtain AoI blood flow data. Cases with structural or chromosomal abnormalities and co-twin death were excluded. The interval from examination to delivery was within 4 weeks and 3 cases over 4 weeks interval were re-examined. Assessment of fetal AoI Doppler parameters were peak systolic velocity (PSV), end-diastolic velocity, times-averaged maximum velocities, pulsatility index (PI), and resistance index (RI). According to the direction of the diastolic flow in the AoI, antegrade and retrograde flow were made and was used to analyze the perinatal outcomes of each fetus. The predictive value of AoI Doppler parameters in predicting fetal growth was obtained by using ANOVA and logistic regression analysis of quantitative variables in each fetus of twins.
There were significant differences in the gestational weeks at delivery, birth weight and the incidence of growth discordance over 20% or more between monochorionic twin and dichorionic twin. The AoI PI and RI were significantly higher in smaller fetus than in larger regardless of chorionicity. Retrograde flow was noted in 8 of 98 cases (8.2%) and the only one case was of the larger fetus and the others were smaller fetuses of twin. Significant correlations were found between the AoI PI and birthweight (P=0.018) and between the PSV and growth discordance (P=0.032). In monochorionic twin, linear correlation was shown between the AoI PI and birthweight (P=0.004) and between AoI PI and growth discordance (P=0.031). Also, the meaningful correlation between the PSV and birthweight (P=0.036) was found by using logistic regression analyses.
On the basis of our observation, AoI PI has revealed their hemodynamic status and this result may improve the understanding of growth patterns in twins.
本研究旨在探讨双胎妊娠中较大胎儿与较小胎儿之间的主动脉峡部（AoI）血流差异；并评估双胎生长中血流动力学变化早期诊断的预测价值。
对49对双胎胎儿进行了这项前瞻性研究，以获取AoI血流数据。排除有结构或染色体异常以及双胎之一死亡的病例。检查至分娩的间隔在4周内，4周以上间隔的3例重新进行了检查。评估胎儿AoI多普勒参数包括收缩期峰值速度（PSV）、舒张末期速度、平均最大速度、搏动指数（PI）和阻力指数（RI）。根据AoI中舒张期血流方向，分为正向和反向血流，并用于分析每个胎儿的围产期结局。通过对双胎中每个胎儿的定量变量进行方差分析和逻辑回归分析，获得AoI多普勒参数在预测胎儿生长方面的预测价值。
单绒毛膜双胎和双绒毛膜双胎在分娩孕周、出生体重以及生长不一致发生率超过20%或更高方面存在显著差异。无论绒毛膜性如何，较小胎儿的AoI PI和RI均显著高于较大胎儿。98例中有8例（8.2%）出现反向血流，其中仅1例为较大胎儿，其余均为双胎中的较小胎儿。发现AoI PI与出生体重之间存在显著相关性（P=0.018），PSV与生长不一致之间存在显著相关性（P=0.032）。在单绒毛膜双胎中，AoI PI与出生体重之间呈线性相关（P=0.004），AoI PI与生长不一致之间呈线性相关（P=
