Fraser W D, Turcot L, Krauss I, Brisson-Carrol G
Cochrane Database Syst Rev. 2007 Jul 18;2006(3):CD000015. doi: 10.1002/14651858.CD000015.pub2.
Early amniotomy has been advocated as a component of the active management of labour. Several randomised trials comparing routine amniotomy to an attempt to conserve the membranes have been published. Their limited sample sizes limit their ability to address the effects of amniotomy on indicators of maternal and neonatal morbidity.
To study the effects of amniotomy on the rate of Cesarean delivery and on other indicators of maternal and neonatal morbidity (Apgar less than 7 at 5 minutes, admission to NICU).
The register of clinical trials maintained and updated by the Cochrane Pregnancy and Childbirth Group.
All acceptably controlled trials of amniotomy during first stage of labour were eligible.
Data were extracted by two trained reviewers from published reports. Trials were assigned methodological quality scores based on a standardized rating system. Typical odds ratios (ORs) were calculated using Peto's method.
Amniotomy was associated with a reduction in labour duration of between 60 and 120 minutes. There was a marked trend toward an increase in the risk of Cesarean delivery: OR = 1.26; 95% Confidence Interval (CI)=0.96-1.66. The likelihood of a 5 minute Apgar score less than 7 was reduced in association with early amniotomy (OR = 0.54; 95% CI = 0.30-0.96). Groups were similar with respect to other indicators of neonatal status (arterial cord pH, NICU admissions). There was a statistically significant association of amniotomy with a decrease in the use of oxytocin: OR = 0.79; 95% CI = 0.67-0.92.
AUTHORS' CONCLUSIONS: Routine early amniotomy is associated with both benefits and risks. Benefits include a reduction in labour duration and a possible reduction in abnormal 5-minute Apgar scores. The meta-analysis provides no support for the hypothesis that routine early amniotomy reduces the risk of Cesarean delivery. Indeed there is a trend toward an increase in Cesarean section. An association between early amniotomy and Cesarean delivery for fetal distress is noted in one large trial. This suggests that amniotomy should be reserved for women with abnormal labour progress.
早期人工破膜一直被提倡作为产程积极管理的一个组成部分。已有多项比较常规人工破膜与保留胎膜尝试的随机试验发表。但这些试验样本量有限，限制了其探讨人工破膜对孕产妇和新生儿发病率指标影响的能力。
研究人工破膜对剖宫产率以及其他孕产妇和新生儿发病率指标（5分钟时阿氏评分低于7分、入住新生儿重症监护病房）的影响。
Cochrane妊娠与分娩小组维护和更新的临床试验注册库。
所有在第一产程中进行人工破膜且对照可接受的试验均符合要求。
由两名经过培训的评审员从已发表报告中提取数据。根据标准化评分系统为试验分配方法学质量评分。使用Peto法计算典型比值比（OR）。
人工破膜与产程缩短60至120分钟相关。剖宫产风险有明显增加趋势：OR = 1.26；95%置信区间（CI）= 0.96 - 1.66。早期人工破膜与5分钟阿氏评分低于7分的可能性降低相关（OR = 0.54；95% CI = 0.30 - 0.96）。在新生儿状况的其他指标（脐动脉血pH值、入住新生儿重症监护病房情况）方面，各分组相似。人工破膜与缩宫素使用减少存在统计学显著关联：OR = 0.79；95% CI = 0.67 - 0.92。
常规早期人工破膜既有益处也有风险。益处包括产程缩短以及5分钟阿氏评分异常情况可能减少。荟萃分析不支持常规早期人工破膜可降低剖宫产风险这一假说。实际上，剖宫产有增加趋势。一项大型试验指出早期人工破膜与因胎儿窘迫行剖宫产之间存在关联。这表明人工破膜应保留用于产程进展异常的女性。
