Lau T K, Lo K W, Wan D, Rogers M S
Department of Obstetrics and Gynaecology, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong.
Br J Obstet Gynaecol. 1997 Jul;104(7):798-802. doi: 10.1111/j.1471-0528.1997.tb12023.x.
To investigate clinical and ultrasonographic predictors of outcome of external cephalic version at term.
Prospective observational study.
University obstetric unit.
All external cephalic versions performed over two years (n = 243).
Nineteen different clinical and ultrasonographic variables were recorded before each procedure. The ability of each of the 19 variables to predict the success or failure of external cephalic version was assessed by univariate analysis. The study population was then divided into two subgroups of 129 and 114 patients by random allocation using computer generated numbers. Logistic regression was performed in each subgroup to assess the relative importance and independence of the important variables. The derived regression models were then applied to the other subgroup of patients to assess accuracy and reproducibility.
The overall success rate of the procedure was 69.5%. Both regression models identified the same three variables as independent predictors of failed versions: 1. presenting part engaged; 2. difficult to palpate the fetal head, and 3. a tense uterus on palpation. The two models correctly predicted 75.2% and 84.2% of outcomes in the other subgroup. If uterine tone, which was assessed after administration of tocolytic, was excluded from the analysis, the other two factors remained in the models, with the addition of nulliparity as a significant predictor of failed external cephalic version. The chance of success of external cephalic version in the original 243 women was found to be < 20% if two of these variables were present, 0% if all three were present, and 94% if none were present.
The outcome of external cephalic version can be predicted by easily available clinical parameters.
探讨足月外倒转术结局的临床及超声预测指标。
前瞻性观察性研究。
大学产科病房。
两年内进行的所有外倒转术（n = 243）。
在每次手术前记录19项不同的临床及超声变量。通过单因素分析评估这19项变量中每项预测外倒转术成功或失败的能力。然后使用计算机生成的数字将研究对象随机分为129例和114例患者的两个亚组。对每个亚组进行逻辑回归分析，以评估重要变量的相对重要性和独立性。然后将推导的回归模型应用于另一亚组患者，以评估准确性和可重复性。
该手术的总体成功率为69.5%。两个回归模型均确定了相同的三个变量作为外倒转术失败的独立预测指标：1. 先露部入盆；2. 难以触及胎头；3. 触诊时子宫紧张。这两个模型在另一亚组中正确预测了75.2%和84.2%的结局。如果将使用宫缩抑制剂后评估的子宫张力排除在分析之外，另外两个因素仍保留在模型中，且初产妇作为外倒转术失败的显著预测指标被纳入。发现如果存在其中两个变量，最初243名女性中外倒转术成功的几率<20%；如果三个变量均存在，成功几率为0%；如果均不存在，则为94%。
外倒转术的结局可通过易于获得的临床参数进行预测。
