Hill Meghan G, Wise Michelle R, Pauleau Emmanuelle, Treadwell Beatrice, Sadler Lynn
Department of Obstetrics and Gynaecology, The University of Auckland, Level 1, Building 507, Grafton, Auckland, 1023, New Zealand.
Women's Health, Te Whatu Ora Te Toka Tumai Auckland, 2 Park Road, Grafton, Auckland, 1023, New Zealand.
Trials. 2025 Jan 22;26(1):27. doi: 10.1186/s13063-025-08722-z.
The approach to induction of labour differs internationally, with timing of amniotomy being controversial. Some institutions favour performing artificial rupture of membranes prior to commencement of oxytocin infusion, with the belief that the labour will progress more efficiently. In other institutions, the approach recommended is for oxytocin infusion with intact amniotic membranes until the person has reached the active phase of labour, citing risk of infection with early amniotomy. Current evidence is inconclusive. We are performing a randomised controlled trial assessing whether delaying amniotomy until the active phase of labour can decrease the rate of chorioamnionitis.
This is a randomised controlled trial at a single centre in New Zealand. Pregnant people undergoing induction of labour at ≥ 37 weeks gestational age with intact membranes and a singleton gestation are eligible for the trial. Participants are randomised to 'Early' amniotomy, at the commencement of oxytocin infusion, or to 'Late' amniotomy, when they have reached a cervical dilation of 6 or more centimetres or when they have been receiving oxytocin infusion for 12 h. The primary outcome of the trial is chorioamnionitis. To detect a decrease in chorioamnionitis from 9 to 3% with a power of 80% and a 95% CI, we will require 488 participants in total, randomised in a 1:1 ratio.
If delaying amniotomy reduces the rate of chorioamnionitis, this is important to inform future practice. Chorioamnionitis entails risk to both the pregnant person and the fetus and is an important contributor to neonatal sepsis, neonatal intensive care unit admission, maternal sepsis, caesarean, wound infection and postoperative infective complications. Conversely, if the rate of chorioamnionitis is not affected by timing of amniotomy, this will allow for safe individualization of care.
The trial is registered on the Australian and New Zealand Clinical Trials Registry, anzctr.org.au. Full registry title is 'Impact of early versus late artificial rupture of membranes during oxytocin induction of labour on the incidence of chorioamnionitis: A randomised controlled trial'.
ACTRN12621000405819. Date registered 14 April 2021.
引产的方法在国际上存在差异，羊膜穿刺术的时机存在争议。一些机构倾向于在开始输注缩宫素之前进行人工破膜，认为这样产程会更顺利。在其他机构，推荐的方法是在胎膜完整的情况下输注缩宫素，直到产妇进入产程活跃期，理由是早期羊膜穿刺术有感染风险。目前的证据尚无定论。我们正在进行一项随机对照试验，评估将羊膜穿刺术推迟到产程活跃期是否能降低绒毛膜羊膜炎的发生率。
这是在新西兰一个中心进行的随机对照试验。孕周≥37周、胎膜完整且为单胎妊娠的引产孕妇符合试验条件。参与者被随机分为“早期”羊膜穿刺术组，即在开始输注缩宫素时进行；或“晚期”羊膜穿刺术组，即当宫颈扩张达到6厘米或以上时，或在接受缩宫素输注12小时后进行。试验的主要结局是绒毛膜羊膜炎。为了以80%的检验效能和95%的置信区间检测绒毛膜羊膜炎发生率从9%降至3%，我们总共需要488名参与者，按1:1的比例随机分组。
如果推迟羊膜穿刺术能降低绒毛膜羊膜炎的发生率，这对于指导未来的实践很重要。绒毛膜羊膜炎对孕妇和胎儿都有风险，是新生儿败血症、新生儿重症监护病房收治、产妇败血症、剖宫产、伤口感染及术后感染并发症的重要原因。相反，如果绒毛膜羊膜炎的发生率不受羊膜穿刺术时机的影响，这将允许进行安全的个体化护理。
该试验已在澳大利亚和新西兰临床试验注册中心（anzctr.org.au）注册。完整的注册标题是“缩宫素引产期间早期与晚期人工破膜对绒毛膜羊膜炎发生率的影响：一项随机对照试验”。
ACTRN12621000405819。注册日期：2021年4月14日。
