Mercer B M, McNanley T, O'Brien J M, Randal L, Sibai B M
Department of Obstetrics and Gynecology, University of Tennessee, Memphis, USA.
Am J Obstet Gynecol. 1995 Oct;173(4):1321-5. doi: 10.1016/0002-9378(95)91379-3.
Our purpose was to determine the impact of early and late amniotomy on labor induction with continuous oxytocin infusion at term.
A total of 209 women admitted for labor induction were randomized to early or late amniotomy. The early amniotomy group (n = 106) had membranes ruptured as soon as it was deemed safe and feasible. The late amniotomy group (n = 103) had membrane rupture performed at > or = 5 cm dilatation. The first 103 women received a continuous oxytocin infusion with incremental adjustments at 60-minute intervals as required. The next 106 women had adjustments every 30 minutes as required. Statistical analysis was confined to concurrent groups.
Early amniotomy was associated with shorter labor (13.3 vs 17.8 hours, p = 0.001), chorioamnionitis (22.6% vs 6.8%, p = 0.002), and significant fetal umbilical cord compression (12.3% vs 2.9%, p = 0.017). The benefit regarding shortening of labor was limited to women having oxytocin increments every 30 minutes as required (13.3 vs 17.8 hours, p = 0.001). Alternatively, the increase in chorioamnionitis was confined to the 60-minute group (39% vs 11%, p < 0.001), which also demonstrated a trend toward increased moderate and severe variable decelerations (19.6% vs 6.4%, p = 0.08).
When a protocol of 60-minute increments in oxytocin infusion rate is desired, amniotomy should be performed late in labor to reduce chorioamnionitis and significant umbilical cord compression. Alternatively, if early amniotomy is necessary, oxytocin should be adjusted every 30 minutes as tolerated.
我们的目的是确定足月时早期和晚期人工破膜对持续静脉滴注缩宫素引产的影响。
总共209名因引产入院的妇女被随机分为早期或晚期人工破膜组。早期人工破膜组（n = 106）在认为安全可行时立即破膜。晚期人工破膜组（n = 103）在宫颈扩张≥5cm时破膜。前103名妇女根据需要每60分钟进行一次持续静脉滴注缩宫素并逐步调整剂量。接下来的106名妇女根据需要每30分钟进行一次调整。统计分析仅限于同期组。
早期人工破膜与产程缩短（13.3小时对17.8小时，p = 0.001）、绒毛膜羊膜炎（22.6%对6.8%，p = 0.002）以及显著的胎儿脐带受压（12.3%对2.9%，p = 0.017）相关。产程缩短的益处仅限于根据需要每30分钟增加缩宫素剂量的妇女（13.3小时对17.8小时，p = 0.001）。另外，绒毛膜羊膜炎的增加仅限于60分钟组（39%对11%，p < 0.001），该组也显示出中度和重度变异减速增加的趋势（19.6%对6.4%，p = 0.08）。
当希望采用缩宫素滴注速率每60分钟增加一次的方案时，应在产程后期进行人工破膜以减少绒毛膜羊膜炎和显著的脐带受压。另外，如果有必要进行早期人工破膜，应根据耐受情况每30分钟调整一次缩宫素。
