Cluver Catherine, Hofmeyr G Justus, Gyte Gillian Ml, Sinclair Marlene
Department of Obstetrics and Gynaecology, Faculty of Health Sciences, Stellenbosch Universityand Tygerberg Hospital, PO Box 19063, Tygerberg, Western Cape, 7505, South Africa.
Cochrane Database Syst Rev. 2012 Jan 18;1:CD000184. doi: 10.1002/14651858.CD000184.pub3.
Breech presentation is associated with increased complications. Turning a breech baby to head first presentation using external cephalic version (ECV) attempts to reduce the chances of breech presentation at birth, and reduce the adverse effects of breech vaginal birth or caesarean section. Tocolytic drugs and other methods have been used in an attempt to facilitate ECV.
To assess interventions such as tocolysis, fetal acoustic stimulation, regional analgesia, transabdominal amnioinfusion or systemic opioids on ECV for a breech baby at term.
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2011) and the reference lists of identified studies.
Randomised and quasi-randomised trials comparing the above interventions with no intervention or other methods to facilitate ECV at term.
We assessed eligibility and trial quality. Two review authors independently assessed for inclusion all potential studies identified as a result of the search strategy and independently extracted the data using a designed data extraction form.
We included 25 studies, providing data on 2548 women. We used the random-effects model for pooling data due to clinical heterogeneity in the included studies in the various comparisons. The overall quality of the evidence was reasonable, but a number of assessments had insufficient data to provide an answer with any degree of assurance.Tocolytic drugs, in particular betastimulants, were effective in increasing cephalic presentations in labour (average risk ratio (RR) 1.38, 95% confidence interval (CI) 1.03 to 1.85, eight studies, 993 women) and in reducing the number of caesarean sections (average RR 0.82, 95% CI 0.71 to 0.94, eight studies, 1177 women). No differences were identified in fetal bradycardias (average RR 0.95, 95% CI 0.48 to 1.89, three studies, 467 women) although the review is underpowered for assessing this outcome. We identified no difference in success, cephalic presentation in labour and caesarean sections between nulliparous and multiparous women. There were insufficient data comparing different groups of tocolytic drugs. Sensitivity analyses by study quality agreed with the overall findings.Regional analgesia in combination with a tocolytic was more effective than the tocolytic alone in terms of increasing successful versions (assessed by the rate of failed ECVs, average RR 0.67, 95% CI 0.51 to 0.89, six studies, 550 women) but there was no difference identified in cephalic presentation in labour (average RR 1.63, 95% CI 0.75 to 3.53, three studies, 279 women) nor in caesarean sections (average RR 0.74, 95% CI 0.40 to 1.37, three studies, 279 women) or fetal bradycardia (average RR 1.48, 95% CI 0.62 to 3.57, two studies, 210 women).There were insufficient data on the use of vibroacoustic stimulation, amnioinfusion or systemic opioids.
AUTHORS' CONCLUSIONS: Betastimulants, to facilitate ECV, increased cephalic presentation in labour and birth, and reduced the caesarean section rate in both nulliparous and multiparous women, but there were insufficient data on adverse effects. Calcium channel blockers and nitric acid donors had insufficient data to provide good evidence. At present we recommend betamimetics for facilitating ECV.There is scope for further research. The possible benefits of tocolysis to reduce the force required for successful version and the possible risks of maternal cardiovascular side effects, need to be addressed further. Further trials are needed to compare the effectiveness of routine versus selective use of tocolysis, the role of regional analgesia, fetal acoustic stimulation, amnioinfusion and the effect of intravenous or oral hydration prior to ECV.Although randomised trials of nitroglycerine are small, the results are sufficiently negative to discourage further trials.
臀位分娩与并发症增加相关。使用外倒转术（ECV）将臀位胎儿转为头先露试图降低出生时臀位分娩的几率，并减少臀位阴道分娩或剖宫产的不良影响。已使用宫缩抑制剂及其他方法来促进外倒转术。
评估诸如宫缩抑制、胎儿声刺激、区域镇痛、经腹羊膜腔灌注或全身使用阿片类药物等干预措施对足月臀位胎儿进行外倒转术的效果。
我们检索了Cochrane妊娠与分娩组试验注册库（2011年9月30日）以及已识别研究的参考文献列表。
比较上述干预措施与不干预或其他促进足月外倒转术方法的随机和半随机试验。
我们评估了纳入资格和试验质量。两位综述作者独立评估所有因检索策略而识别出的潜在研究是否符合纳入标准，并使用设计好的数据提取表独立提取数据。
我们纳入了25项研究，提供了2548名女性的数据。由于纳入研究在各种比较中存在临床异质性，我们使用随机效应模型合并数据。证据的总体质量合理，但一些评估数据不足，无法提供任何程度的确定答案。宫缩抑制剂，特别是β激动剂，在增加分娩时头先露方面有效（平均风险比（RR）1.38，95%置信区间（CI）1.03至1.85，8项研究，993名女性），并减少了剖宫产数量（平均RR 0.82，95%CI 0.71至0.94，8项研究，1177名女性）。虽然该综述评估此结果的效能不足，但在胎儿心动过缓方面未发现差异（平均RR 0.95，95%CI 0.48至1.89，3项研究，467名女性）。我们未发现初产妇和经产妇在成功率、分娩时头先露及剖宫产方面存在差异。比较不同组宫缩抑制剂的数据不足。按研究质量进行的敏感性分析与总体结果一致。与单独使用宫缩抑制剂相比，区域镇痛联合宫缩抑制剂在提高成功倒转率方面更有效（通过外倒转术失败率评估，平均RR 0.67，95%CI 0.51至0.89，6项研究，550名女性），但在分娩时头先露方面未发现差异（平均RR 1.63，95%CI 0.75至3.53，3项研究，279名女性），在剖宫产方面也未发现差异（平均RR 0.74，95%CI 0.40至1.37，3项研究，279名女性）或胎儿心动过缓方面也未发现差异（平均RR 1.48，95%CI 0.62至3.57，2项研究，210名女性）。关于使用振动声刺激、羊膜腔灌注或全身使用阿片类药物的数据不足。
β激动剂促进外倒转术，增加了分娩时头先露及出生时头先露，并降低了初产妇和经产妇的剖宫产率，但关于不良反应的数据不足。钙通道阻滞剂和硝酸供体的数据不足，无法提供充分证据。目前我们推荐使用β拟交感神经药物促进外倒转术。仍有进一步研究的空间。宫缩抑制减少成功倒转所需力量的潜在益处以及母体心血管副作用的潜在风险，需要进一步探讨。需要进一步试验来比较常规使用与选择性使用宫缩抑制剂的有效性、区域镇痛的作用、胎儿声刺激作用、羊膜腔灌注以及外倒转术前静脉或口服补液的效果。尽管硝酸甘油的随机试验规模较小，但其结果足够负面，不鼓励进一步试验。
