Interventions for helping to turn term breech babies to head first presentation when using external cephalic version.

BACKGROUND: 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.
OBJECTIVES: To assess interventions such as tocolysis, fetal acoustic stimulation, regional analgesia, transabdominal amnioinfusion or systemic opioids on ECV for a breech baby at term. SEARCH
METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2011) and the reference lists of identified studies. SELECTION CRITERIA: Randomised and quasi-randomised trials comparing the above interventions with no intervention or other methods to facilitate ECV at term. DATA COLLECTION AND ANALYSIS: 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. MAIN
RESULTS: 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.