妊娠中期超声对持续性前置胎盘预测价值的研究

Value of ultrasonography in prediction of persistent placenta previa during second-trimester of pregnancy

目的探讨前置胎盘妊娠妇女妊娠中期的超声影像学表现对持续性前置胎盘(PPP)的预测价值。方法选择妊娠早、中期超声检查显示胎盘处于低置和/或前置状态的200例单胎孕妇,按产检孕周分为11~13+6周、14~17+6周、18~23+6周、24~27+6周4个阶段进行检查,观察胎盘附着位置,测量胎盘下缘距宫颈内口的距离,在孕晚期经超声检查确定胎盘状态。结果受检孕妇中有28例在孕晚期超声诊断为前置胎盘,结果均通过剖宫产术后或分娩后证实。对28例前置胎盘研究发现,不同孕周胎盘下缘距宫颈内口距离可初步预测PPP的可能性:在11~13+6周,胎盘下缘距宫颈内口距离≥21.8 mm时,PPP敏感性为77.810%,特异性为80.402%;在14~17+6周,胎盘下缘距宫颈内口距离≥18.2 mm时,PPP敏感性为82.322%,特异性为83.318%;在18~23+6周,胎盘下缘距宫颈内口距离≥14.5 mm时,PPP敏感性为87.531%,特异性为85.715%;在24~27+6周,胎盘下缘距宫颈内口距离≥11.2 mm时,PPP敏感性为96.407%,特异性为83.342%。结论在前置胎盘中,不同孕周胎盘下缘与宫颈内口间的距离能用于预测PPP的可能性,对临床指导及判断预后具有重要的价值。

Objective To study the value of uhrasonographie findings in prediction of persistent placenta previa （PPP） during the second-trimester of pregnancy. Methods This was a prospective study involving 200 singleton pregnancies with low-lying placenta and/or placenta previa early in the second-trimester of pregnancy. The placenta adhesion location was observed and the distance between the lower placenta edge and the inter- nal cervical os was measured in （11-13＋6） weeks, （14-17＋6） weeks, （18-23＋6） weeks and （24-27＋6） weeks. State of the placenta was determined by uhrasonography in late pregnancy. Results Among the pregnant women, 28 eases were diagnosed was placenta previa by ultrasonography in late pregnancy. All the results were confirmed after cesarean or delivery. In the study of 28 cases with placenta previa, it was found that the distance between the lower plaeenta edge and the internal cervical os could be used to predict the possibility of PPP in different gestational age： in （11-13＋6） weeks of gestation, when the distance was ≥21.8 mm, the sensitivity was 77.810% and the specificity was 80.402%; in （14-17＋6） weeks of gestation, when the distance was ≥18.2 mm, the sensitivity was 82.322% and the specificity was 83.318%; in （18-23＋6） weeks of gestation, when the distance was ≥14.5 mm, the sensitivity was 87.531% and the specificity was 85.715%; in （24-27＋6） weeks of gestation, when the distance was 〉111.2 ram, the sensitivity was 96.407% and the specificity was 83.342%. Conclusions For placenta previa, the distance between the lower placenta edge and the internal cervical os in different gestational age can be used to predict the possibility of PPP and has important value for clinicalguidance and prognoslic prediction.