Bian X, Zhuang J, Cheng X
Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Beijing, China.
Chin Med J (Engl). 1997 Dec;110(12):942-5.
To assess a method of antepartum diagnosis of cephalopelvic disproportion by comparing the diameters of fetal head with those of the maternal midpelvis.
Transvaginal ultrasound pelvimetry was performed on 190 healthy primigravidas with cephalic presentation at 28-35 weeks of gestation, and the fetal heads were measured within one week before delivery. The cephalopelvic indices of diameter, circumference and area were calculated and compared.
The index exhibiting the highest degree of accuracy (77.9%) was the cephalopelvic index of diameter (CID) defined as the difference between the mean diameter of the midpelvis and the fetal biparietal diameter (BPD). Eighty-three percent of the cases with CID less than 15.8 mm needed operative delivery, and 76.2% of the cases with CID more than 15.8 mm underwent vaginal delivery.
The CID may be used to identify cephalopelvic disproportion before the labor and help obstetricians choose the most appropriate form of delivery in an uncomplicated vertex presentation.
通过比较胎儿头部直径与母体中骨盆直径，评估一种头盆不称的产前诊断方法。
对190例孕28 - 35周、头先露的健康初产妇进行经阴道超声骨盆测量，并在分娩前一周内测量胎儿头部。计算并比较直径、周长和面积的头盆指数。
准确性最高（77.9%）的指数是直径头盆指数（CID），定义为中骨盆平均直径与胎儿双顶径（BPD）之差。CID小于15.8 mm的病例中83%需要手术分娩，CID大于15.8 mm的病例中76.2%经阴道分娩。
CID可用于在分娩前识别头盆不称，并帮助产科医生在单纯头先露情况下选择最合适的分娩方式。
