Data from: Umbilical vein oxytocin for the treatment of retained placenta (Release Study): a double-blind, randomised controlled trial.

BACKGROUND: Retained placenta is associated with post-partum haemorrhage. Meta-analysis has suggested that umbilical injection of oxytocin could increase placental expulsion without the need for a surgeon or anaesthetic. We assessed the effect of high-dose umbilical vein oxytocin as a treatment for retained placenta. METHODS: In this double-blind, placebo-controlled trial, haemodynamically stable women with a retained placenta for more than 30 min were recruited from 13 sites in the UK, Uganda, and Pakistan. 577 women were randomly assigned by a computer-generated randomisation list stratified by centre to 30 mL saline containing either 50 IU oxytocin (n=292) or 5 mL water (n=285), which was injected into the placenta through an umbilical vein catheter. All trial participants, study workers, and data handlers were masked to individual allocations. The primary outcome was the need for manual removal of the placenta. Analysis was by intention to treat. This study is registered, number ISRCTN 13204258. FINDINGS: The primary outcome was recorded for all participants. We detected no difference between the groups in the need for manual removal of placenta (oxytocin 179/292 [61.3%] vs placebo 177/285 [62.1%]; relative risk 0.98, 95% CI 0.87-1.12; p=0.84). The need for manual removal was higher in the UK (overall 250/361 [69%]) than in Uganda (90/190 [47%]) or Pakistan (16/26 [62%]). Adverse events did not differ between the two groups. INTERPRETATION: Umbilical oxytocin has no clinically significant effect on the need for manual removal for women with retained placenta. FUNDING: WHO, WellBeing of Women, Pakistan Higher Education Commission.

背景：胎盘滞留（retained placenta）与产后出血（post-partum haemorrhage）存在显著关联。荟萃分析（meta-analysis）表明，脐部注射催产素（oxytocin）可在无需外科医师或麻醉操作的前提下促进胎盘娩出。本研究旨在评估大剂量脐静脉催产素治疗胎盘滞留的临床效果。

方法：本项双盲安慰剂对照试验（double-blind, placebo-controlled trial）从英国、乌干达及巴基斯坦的13个研究中心招募了胎盘滞留时长超过30分钟且血流动力学稳定的女性受试者。通过计算机生成的按中心分层的随机分配列表，将577名女性随机分为两组：试验组经脐静脉导管向胎盘内注入含50 IU催产素的30 mL生理盐水（n=292），对照组注入5 mL灭菌注射用水（n=285）。所有受试者、研究人员及数据处理人员均对分组分配实施设盲。本研究的主要结局为是否需要徒手剥离胎盘。分析采用意向治疗（intention to treat）原则。本研究已完成注册，注册号为ISRCTN 13204258。

结果：所有受试者均记录了主要结局数据。两组间需行徒手剥离胎盘的比例无统计学差异：试验组为179/292 [61.3%]，对照组为177/285 [62.1%]；相对风险（relative risk）为0.98，95%置信区间（95% CI）为0.87~1.12；p=0.84。英国中心的徒手剥离胎盘整体需求率为250/361 [69%]，高于乌干达中心的90/190 [47%]及巴基斯坦中心的16/26 [62%]。两组不良事件（adverse events）的发生率无显著差异。

解读：脐部注射催产素对胎盘滞留女性需行徒手剥离胎盘的临床必要性未产生具有临床意义的影响。

资助：世界卫生组织（WHO）、女性福祉项目（WellBeing of Women）、巴基斯坦高等教育委员会。