应用阴道超声测量骨盆及胎头径线指数预测相对头盆不称的研究

Prediction of Cephalopelvic Disproportion by Ultrasonographic Cephalopelic

目的探讨应用阴道超声测量胎儿头盆指数，诊断相对头盆不称的方法。方法对１９０例初产妇分为阴道分娩组（１１７例）和手术分娩组（７３例）。在孕２８～３５周时应用阴道超声行骨盆测量，在分娩前１周行超声测量胎儿双顶径和头围，计算出径线，周长和面积的头盆指数，并与分娩结果比较。结果各种头盆指数在手术分娩组和阴道分娩组间均有显著性差异。其中定义为骨盆中腔前后径与横径的均值与胎儿双顶径之差的径线头盆指数（ＣＩＤ）准确率最高（７７．９％）。ＣＩＤ≤１５．８ｍｍ时，８３．０％的孕妇需手术分娩，ＣＩＤ＞１５．８ｍｍ时，７２．６％的孕妇可顺利经阴道分娩。结论应用阴道超声行骨盆测量和ＣＩＤ预测相对头盆不称，是一种简单实用的方法，可协助产科临床恰当地选择分娩方式。

Objective To develop a prospective antepartum method of identifying cephalopelvic disproportion by comparing the diameters of fetal head with those of the maternal midpelvis. Methods Transvaginal ultrasound pelvimetry was performed on 190 healthy primigravidas with cephalic presentation at 28～35 weeks of gestation, and the diameters of their fetal heads were meassured within one week prior to delivery. These indices the cephalopelvic indices of diameter, cirumference and area, were calculated and compared. Results The cephalopelvic index of diameter (CID), defined as the difference between the mean diameter of the midpelvis and the fetal biparetal diaameter (BPD), showed the highest degree of accuracy (77.9%). Eighty three percent of woomen with CID less than 15.8 needed operative delivery; 76.2% of those with CId more than 15.8 mm underwent vaginal delivery. Conclusions Transvaginal ultrasound pelvimetry and the CID by and large seems to be able to identify cephalopelvic disproportion before labor and may help obsetricians choose the most appropriate form of delivery in an uncomplicated vertex presentation.