母血中胎儿DNA预测前置胎盘合并粘连的探讨

目的:通过实时荧光定量PCR方法测定孕妇外周血中胎儿DNA量,初步探讨前置胎盘合并胎盘粘连孕妇外周血中胎儿DNA量与正常对照组有无统计学差异;母血中胎儿DNA定量能否预测前置胎盘合并胎盘粘连。方法:收集35例孕28~34周且胎儿为男性,经我院B超诊断为前置胎盘的单胎孕妇作为研究组,其中合并胎盘粘连8例经手术确诊,称为前置胎盘粘连组,未合并胎盘粘连27例称为前置胎盘未粘连组。收集30例孕28~34周,且胎儿为男性,正常单胎妊娠孕妇作为对照组,通过实时荧光定量PCR方法测定3组孕妇外周血中胎儿DNA量,比较3组结果的异同。结果:前置胎盘粘连组孕妇外周血中胎儿DNA量高于对照组,差异有统计学意义(P<0.05)。前置胎盘未粘连组孕妇外周血中胎儿DNA量与对照组差异无统计学意义(P>0.05)。前置胎盘粘连组孕妇外周血中胎儿DNA量高于未合并胎盘粘连组,差异有统计学意义(P<0.05)。孕妇外周血中胎儿DNA量与前置胎盘类型无关,差异无统计学意义(P>0.05)。结论:孕妇外周血中胎儿DNA量与胎盘粘连与否有关,即与胎盘组织的功能状态有关。因此测定孕妇外周血中胎儿DNA量可能有助于预测前置胎盘合并胎盘粘连。

The value of the quantitative analysis of fetal DNA in maternal plasma in predicting placenta praevia with placenta accreta

Objective:Apply real-time polymerase chain reaction(PCR) to quantify fetal DNA in maternal plasma,to compare the difference of level of fetal DNA between pregnant women with placenta accreta and the controls;to study if it can be used to predict pregnant women with placenta accreta prenatally.Methods:Blood was drawn from 35 pregnant women(28~34 weeks' gestation,all singleton pregnancy,male fetus) with placenta praevia diagnosed by ultrasonagraphy.The diagnosis of placenta praevia with placenta accreta was confirmed clinically after operation,they were classified as study group with placenta accreta.Others without placenta accreta were classified as study group without placenta accreta.Blood was also drawn from 30 normal pregnant women(28~34 weeks' gestation,all singleton,male fetus),as controls.DNA was isolated from the plasma and quantified by Real-time PCR for the Y chromosome-specific sequences.The differences among three groups were compared.Results:The level of fetal DNA in study group with placenta accreta was higher than that of controls(P<0.05).When comparing the level of fetal DNA,there was no statistical differences between study group without placenta accreta and controls(P>0.05).Between study group with and without placenta accreta,the level of fetal DNA in former group was also higher(P<0.05).The level of fetal DNA was not related to the type of placenta praevia(P>0.05).Conclusion:The level of fetal DNA is much higher in study group with placenta accreta than without placenta accreta and controls.The level of fetal DNA is correlated with the condition of placenta tissue,it maybe helpful to predict placenta accreta prenatally.