单绒毛膜双羊膜囊双胎妊娠合并选择性生长受限时的脑-胎盘血流分布特征

Cerebroplacental blood flow redistribution in monochorionic-diamniotic twin pregnancies with selective fetal growth restriction

目的分析单绒毛膜双羊膜囊(MCDA )双胎合并选择性生长受限(sFGR)时的脑-胎盘血流分布特征,探讨脑-胎盘血流差异与出生体重差异的关系.方法回顾性分析52例正常生长MCDA双胎妊娠(对照组)与52例MCDA双胎妊娠合并sFGR (病例组)时的脑-胎盘血流分布特征及差异,包括脐动脉搏动指数(U A‐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)、脑-胎盘率(CPR)、 UA‐PI差异(UA‐PIdisc)、 MCA‐PSV差异(MCA‐PSVdisc )、 MCA‐PI差异(MCA‐PIdisc )和CPR差异(CPRdisc ).结果与对照组比较,病例组 U A‐PIdisc 、 MCA‐PIdisc和CPRdisc均明显增高(均 P <0 .01).相关性分析显示 U A‐PIdisc 、 MCA‐PIdisc和CPRdisc与出生体重差异呈显著正相关( r =0 .488 , 0 .414 ,0 .592;均 P <0 .001), ROC曲线显示这些指标诊断sFGR的曲线下面积分别为 0 .743 、 0 .662 和 0 .778 ,敏感性分别为 48 .08%、 67 .31%和 71 .15%,特异性分别为92 .31%、 59 .62%和78 .85%(均 P <0 .05).多因素回归分析显示只有CPRdisc是sFGR的独立预测因素.结论 MCDA双胎妊娠合并sFGR时,双胎间脑-胎盘血流灌注差异明显增加;双胎间脑-胎盘血流差异与出生体重差异密切相关.

Objective To analyze the cerebroplacental blood flow distribution characteristics in monochorionic-diamniotic (MCDA) twin pregnancies with selective fetal growth restriction (sFGR), and investigate the relationship between co-twin cerebroplacental blood flow discordances and co-twin birth weight discordances (BWdisc). Methods The cerebroplacental blood flow distribution characteristics and their discordances were analyzed retrospectively in 52 MCDA twin pregnancies with normal growth (control group) and 52 with sFGR (case group), including the umbilical artery pulsatility index (UA-PI), middle cerebral artery peak systolic velocity (MCA-PSV), middle cerebral artery pulsatility index (MCA-PI), cerebroplacental ratio (CPR), and their discordances (UA-PIdisc, MCA-PSVdisc, MCA-PIdisc and CPRdisc). Results Compared to the control group, UA-PIdisc, MCA-PIdisc and CPRdisc increased significantly (all P<0.01). UA-PIdisc, MCA-PIdisc and CPRdisc were related positively to BWdisc as shown by correlation analyses (r=0.488, 0.414, 0.592;all P<0.001), and they had moderate predictive accuracy for sFGR with area under the curves of 0.743, 0.662 and 0.778, with sensitivity of 48.08%, 67.31% and 71.15%, and specificity of 92.31%, 59.62% and 78.85%(all P<0.01). Multivariate Logistic regression analyses showed that only CPRdisc were independently associated with sFGR (P<0.05). Conclusions More cerebroplacental blood flow discordances are observed in MCDA twin pregnancies with sFGR. Co-twin cerebroplacental blood flow discordance is related to BWdisc.