摘要目的:分析单绒毛膜双羊膜囊(MCDA)双胎合并双胎输血综合征(TTTS)Ⅰ～Ⅱ期时胎儿脑－胎盘血流分布特征，探讨脑－胎盘率(CPR)在预测双胎输血综合征Ⅱ期中的价值。方法:回顾性分析2017年6月至2019年6月重庆医科大学附属第一医院诊断的68例TTTS(包括Ⅰ期、Ⅱ期各34例)胎儿脑－胎盘血流参数及其差异，包括脐动脉搏动指数(UA-PI)、大脑中动脉收缩期峰值流速(MCA-PSV)、大脑中动脉搏动指数(MCA-PI)、CPR、UA-PI差异(UA-PI disc)、MCA-PSV差异(MCA-PSV disc)、MCA-PI差异(MCA-PI disc)与CPR差异(CPR disc)。 结果:TTTSⅡ期中供血儿与受血儿UA-PI、MCA-PI及CPR差异有统计学意义(均 P<0.05)；Ⅰ期与Ⅱ期的UA-PI disc 、MCA-PI disc和CPR disc差异有统计学意义(均 P<0.05)。多因素回归分析显示，只有CPR disc是TTTSⅡ期的独立预测因素( P<0.05)。ROC曲线显示，CPR disc诊断TTTSⅡ期的曲线下面积为0.766，敏感性为64.71%，特异性为82.35%( P<0.001)。 结论:MCDA双胎妊娠合并TTTSⅡ期时，双胎间脑－胎盘血流灌注出现明显差异，其中CPR disc与Ⅱ期密切相关。

abstractsObjective:To analyze the cerebroplacental blood flow distribution characteristics in monochorionic-diamniotic(MCDA) twin pregnancies with stageⅠ-Ⅱof twin-twin transfusion syndrome (TTTS), and investigate the predictive value of cerebroplacental ratio (CPR) in the stageⅡ of TTTS.Methods:The cerebroplacental blood flow distribution were analyzed retrospectively in 68 cases from June 2017 to June 2019 in the First Affiliated Hospital of Chongqing Medical University (34 cases for each stage) with TTTS, including the umbilical artery pulsatility index (UA-PI), middle cerebral artery peak systolic velocity (MCA-PSV), middle cerebral artery pulsatility index (MCA-PI), CPR, and their discordances(UA-PI disc, MCA-PSV disc, MCA-PI disc and CPR disc). Results:The differences of UA-PI, MCA-PI, and CPR between donors and recipients in TTTS Ⅱ were statistically significant (all P<0.05), the differences of UA-PI disc, MCA-PI disc and CPR disc between TTTS Ⅰ and TTTS Ⅱ were statistically significant (all P<0.05). Multivariate Logistic regression analyses showed that only CPR disc was independently associated with the stage Ⅱ of TTTS( P<0.05), and it had moderate predictive accuracy for the stage Ⅱ of TTTS with an area under the curve of 0.766, a sensitivity of 64.71% and a specificity of 82.35%( P<0.001). Conclusions:More cerebroplacental blood flow discordances are observed and CPR disc is closely related to stageⅡof TTTS.